• 《Jetpack Compose从入门到实战》 第二章 了解常用UI组件


    在这里插入图片描述
    书附代码
    Google的图标库

    常用的基础组件

    文字组件

    
    @Composable
    fun TestText() {
        Column(modifier = Modifier.verticalScroll(state = rememberScrollState())) {
            Text(text = "hello world")
            Text(text = "hello world")
            Text(text = "hello world")
            Text(text = stringResource(id = R.string.hello_world))
            Text(
                text = stringResource(id = R.string.hello_world),
                style = TextStyle(
                    fontSize = 25.sp,//字体大小
                    fontWeight = FontWeight.Bold,//字体粗细
                    fontStyle = FontStyle.Italic,//斜体,
                    background = Color.Cyan,
                    lineHeight = 35.sp,//行高
                ),
            )
            Text(
                text = stringResource(id = R.string.hello_world),
                style = TextStyle(color = Color.Gray, letterSpacing = 4.sp)
            )
            Text(
                text = stringResource(id = R.string.hello_world),
                style = TextStyle(textDecoration = TextDecoration.LineThrough)
            )
    
            Text(
                text = stringResource(id = R.string.hello_world),
                style = MaterialTheme.typography.h6.copy(fontStyle = FontStyle.Italic)
            )
    
            Text(
                text = "Hello Compose, Compose是下一代Android UI工具包, 开发起来和以往XML写布局有着非常大的不同",
                style = MaterialTheme.typography.body1
            )
            Text(
                text = "Hello Compose, Compose是下一代Android UI工具包, 开发起来和以往XML写布局有着非常大的不同",
                style = MaterialTheme.typography.body1,
                maxLines = 1
            )
            Text(
                text = "Hello Compose, Compose是下一代Android UI工具包, 开发起来和以往XML写布局有着非常大的不同",
                style = MaterialTheme.typography.body1,
                maxLines = 1,
                overflow = TextOverflow.Ellipsis,
            )
    
            Text(text = stringResource(id = R.string.hello_world), fontFamily = FontFamily.Cursive)
            Text(text = stringResource(id = R.string.hello_world), fontFamily = FontFamily.Monospace)
            Text(
                text = "你好,我的世界", fontFamily = FontFamily(Font(R.font.test_font))
            )
    
            Text(text = buildAnnotatedString {
                appendLine("-------------------------------")
                withStyle(style = SpanStyle(fontSize = 24.sp)) {
                    append("你现在学的章节是")
                }
                withStyle(style = SpanStyle(fontWeight = FontWeight.W900, fontSize = 24.sp)) {
                    append("Text")
                }
                appendLine()
                withStyle(style = ParagraphStyle(lineHeight = 25.sp)) {
                    append("在刚刚讲过的内容中, 我们学会了如何应用文字样式, 以及如何限制文本的行数和处理溢出的视觉效果")
                }
                appendLine()
                append("现在,我们正在学习")
                withStyle(
                    style = SpanStyle(
                        fontWeight = FontWeight.W900,
                        textDecoration = TextDecoration.Underline,
                        color = Color(0xFF59A869)
                    )
                ) {
                    append("AnnotatedString")
                }
    
            })
            val annotatedString = buildAnnotatedString {
                withStyle(style = ParagraphStyle()) {
                    append("点击下面的链接查看更多")
                    pushStringAnnotation(
                        tag = "URL", annotation = "https://jetpackcompose.cn/docs/elements/text"
                    )
                    withStyle(
                        style = SpanStyle(
                            fontWeight = FontWeight.W900,
                            textDecoration = TextDecoration.Underline,
                            color = Color(0xFF59A869)
                        )
                    ) {
                        append("参考链接")
                    }
                    pop()//结束之前添加的样式
                    appendLine("-------------------------------")
                }
            }
    
            val currentContext = LocalContext.current
            ClickableText(text = annotatedString, onClick = { offset ->
                annotatedString.getStringAnnotations(tag = "URL", start = offset, end = offset)
                    .firstOrNull()?.let { annotation ->
                        val uri: Uri = Uri.parse(annotation.item)
                        val intent = Intent(Intent.ACTION_VIEW, uri)
                        startActivity(currentContext, intent, null)
                    }
            })
    
            SelectionContainer {
                Text(text = "可以被选中复制的文字")
            }
            TestTextField()
        }
    }
    
    @Composable
    fun TestTextField() {
        var textFields by remember { mutableStateOf("") }
        TextField(value = textFields,
            onValueChange = { textFields = it },
            label = { Text(text = "user name") })
    
        var userName by remember {
            mutableStateOf("")
        }
    
        var password by remember {
            mutableStateOf("")
        }
    
        TextField(value = userName,
            onValueChange = { userName = it },
            label = { Text(text = "用户名") },
            leadingIcon = {
                Icon(
                    imageVector = Icons.Filled.AccountBox, contentDescription = "username"
                )
            })
    
        TextField(value = password,
            onValueChange = { password = it },
            label = { Text(text = "密码") },
            trailingIcon = {
                IconButton(onClick = {}) {
                    Icon(
                        painter = painterResource(id = R.drawable.visibility),
                        contentDescription = "password"
                    )
                }
            })
        var outlinedTextFields by remember { mutableStateOf("Hello World") }
        OutlinedTextField(value = outlinedTextFields, onValueChange = { outlinedTextFields = it })
    
        //不是basicTextField,属性被material theme所限制,例如修改高度,输入区域会被截断,影响显示效果
        TextField(value = userName,
            onValueChange = { userName = it },
            label = { Text(text = "用户名") },
            leadingIcon = {
                Icon(
                    imageVector = Icons.Filled.AccountCircle, contentDescription = null
                )
            },
            modifier = Modifier.height(30.dp)
        )
    
    
        var basicTextFields by remember { mutableStateOf("") }
    
        BasicTextField(
            value = basicTextFields,
            onValueChange = { basicTextFields = it },
            decorationBox = { innerTextField ->
                Column {
                    innerTextField.invoke()//innerTextField代表输入框开始输入的位置,需要在合适的地方调用
                    Divider(
                        thickness = 1.dp, modifier = Modifier
                            .fillMaxWidth()
                            .background(Color.Black)
                    )
                }
            },
            modifier = Modifier
                .height(40.dp)
                .background(Color.Cyan),
        )
        Spacer(modifier = Modifier.height(15.dp))
        SearchBar()
        Spacer(modifier = Modifier.height(15.dp))
    
    }
    
    @Composable
    fun SearchBar() {
        var searchText by remember { mutableStateOf("") }
        Box(
            modifier = Modifier
                .fillMaxWidth()
                .height(50.dp)
                .background(Color(0xFFD3D3D3)),
            contentAlignment = Alignment.Center
        ) {
            BasicTextField(
                value = searchText,
                onValueChange = { searchText = it },
                decorationBox = { innerTextField ->
                    Row(
                        verticalAlignment = Alignment.CenterVertically,
                        modifier = Modifier.padding(vertical = 2.dp, horizontal = 8.dp)
                    ) {
                        Icon(imageVector = Icons.Filled.Search, contentDescription = "")
                        Box(
                            modifier = Modifier
                                .padding(horizontal = 10.dp)
                                .weight(1f),
                            contentAlignment = Alignment.CenterStart
                        ) {
                            if (searchText.isEmpty()) {
                                Text(text = "搜索", style = TextStyle(color = Color(0, 0, 0, 128)))
                            }
                            innerTextField()
                        }
                        if (searchText.isNotEmpty()) {
                            IconButton(
                                onClick = { searchText = "" }, modifier = Modifier.size(16.dp)
                            ) {
                                Icon(imageVector = Icons.Filled.Clear, contentDescription = "")
                            }
                        }
                    }
                },
                modifier = Modifier
                    .padding(horizontal = 10.dp)
                    .height(30.dp)
                    .fillMaxWidth()
                    .background(Color.White, CircleShape),
            )
        }
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    • 64
    • 65
    • 66
    • 67
    • 68
    • 69
    • 70
    • 71
    • 72
    • 73
    • 74
    • 75
    • 76
    • 77
    • 78
    • 79
    • 80
    • 81
    • 82
    • 83
    • 84
    • 85
    • 86
    • 87
    • 88
    • 89
    • 90
    • 91
    • 92
    • 93
    • 94
    • 95
    • 96
    • 97
    • 98
    • 99
    • 100
    • 101
    • 102
    • 103
    • 104
    • 105
    • 106
    • 107
    • 108
    • 109
    • 110
    • 111
    • 112
    • 113
    • 114
    • 115
    • 116
    • 117
    • 118
    • 119
    • 120
    • 121
    • 122
    • 123
    • 124
    • 125
    • 126
    • 127
    • 128
    • 129
    • 130
    • 131
    • 132
    • 133
    • 134
    • 135
    • 136
    • 137
    • 138
    • 139
    • 140
    • 141
    • 142
    • 143
    • 144
    • 145
    • 146
    • 147
    • 148
    • 149
    • 150
    • 151
    • 152
    • 153
    • 154
    • 155
    • 156
    • 157
    • 158
    • 159
    • 160
    • 161
    • 162
    • 163
    • 164
    • 165
    • 166
    • 167
    • 168
    • 169
    • 170
    • 171
    • 172
    • 173
    • 174
    • 175
    • 176
    • 177
    • 178
    • 179
    • 180
    • 181
    • 182
    • 183
    • 184
    • 185
    • 186
    • 187
    • 188
    • 189
    • 190
    • 191
    • 192
    • 193
    • 194
    • 195
    • 196
    • 197
    • 198
    • 199
    • 200
    • 201
    • 202
    • 203
    • 204
    • 205
    • 206
    • 207
    • 208
    • 209
    • 210
    • 211
    • 212
    • 213
    • 214
    • 215
    • 216
    • 217
    • 218
    • 219
    • 220
    • 221
    • 222
    • 223
    • 224
    • 225
    • 226
    • 227
    • 228
    • 229
    • 230
    • 231
    • 232
    • 233
    • 234
    • 235
    • 236
    • 237
    • 238
    • 239

    在这里插入图片描述

    图片组件

    @Composable
    fun TestImage() {
        Column {
    
            //Material Icon默认的tint颜色会是黑色, 所以彩色的icon,也会变成黑色
            Icon(
                imageVector = ImageVector.vectorResource(id = R.drawable.collect),//xml svg矢量图
                contentDescription = "矢量图资源"
            )
            //将tint设置为Color.Unspecified, 即可显示出多色图标
            Icon(
                imageVector = ImageVector.vectorResource(id = R.drawable.collect),//xml svg矢量图
                contentDescription = "矢量图资源", tint = Color.Unspecified
            )
    
            Icon(
                bitmap = ImageBitmap.imageResource(id = R.drawable.gallery), contentDescription = "图片资源"//加载jpg或png
            )
    
            Icon(painter = painterResource(id = R.drawable.visibility), contentDescription = "任意类型的资源")//任意类型的资源文件
    
            Image(
                imageVector = ImageVector.vectorResource(id = R.drawable.collect),//xml svg矢量图
                contentDescription = "矢量图资源"
            )
    
            Image(
                bitmap = ImageBitmap.imageResource(id = R.drawable.gallery), contentDescription = "图片资源"//加载jpg或png
            )
    
            Image(painter = painterResource(id = R.drawable.visibility), contentDescription = "任意类型的资源")//任意类型的资源文件
    
        }
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34

    按钮组件

    @Composable
    fun TestButton() {
        Column {
            Button(onClick = {}, contentPadding = PaddingValues(2.dp)) {
                Text(text = "确认")
            }
    
            Button(
                onClick = {},
                contentPadding = PaddingValues(5.dp),
                colors = ButtonDefaults.buttonColors(
                    backgroundColor = Color.Cyan, contentColor = Color.Gray
                )
            ) {
                Icon(
                    imageVector = Icons.Filled.Done,
                    contentDescription = "",
                    modifier = Modifier.size(ButtonDefaults.IconSize)
                )
                Spacer(modifier = Modifier.width(ButtonDefaults.IconSpacing))
                Text(text = "确认")
            }
    
            val interactionSource = remember {
                MutableInteractionSource()
            }
            val isPressedAsState = interactionSource.collectIsPressedAsState()
            val borderColor = if (isPressedAsState.value) Color.Green else Color.Cyan
    
            Button(
                onClick = {},
                contentPadding = PaddingValues(horizontal = 12.dp),
                border = BorderStroke(2.dp, borderColor),
                interactionSource = interactionSource
            ) {
                Text(text = "long press")
            }
    
            IconButton(onClick = {}) {
                Icon(
                    painter = painterResource(id = R.drawable.collect_24_x_24),
                    contentDescription = "",
                    tint = Color.Unspecified
                )
            }
    
            FloatingActionButton(onClick = {}) {
                Icon(
                    Icons.Filled.KeyboardArrowUp, contentDescription = ""
                )
            }
    
            ExtendedFloatingActionButton(icon = {
                Icon(
                    Icons.Filled.Favorite, contentDescription = "", tint = Color.Unspecified
                )
            }, text = { Text(text = "add to my favorite") }, onClick = {})
    
        }
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60

    选择器组件

    @Composable
    fun TestSelector() {
        Column(modifier = Modifier.verticalScroll(rememberScrollState())) {
            val checkedState = remember {
                mutableStateOf(true)
            }
            Checkbox(
                checked = checkedState.value,
                onCheckedChange = { checkedState.value = it },
                colors = CheckboxDefaults.colors(checkedColor = Color(0xFF0079D3))
            )
    
            val (state, onStateChange) = remember {
                mutableStateOf(true)
            }
            val (state2, onStateChange2) = remember {
                mutableStateOf(true)
            }
            val parentState = remember(state, state2) {
                if (state && state2) ToggleableState.On
                else if (!state && !state2) ToggleableState.Off
                else ToggleableState.Indeterminate
            }
            val onParentClick = {
                val s = parentState != ToggleableState.On
                onStateChange(s)
                onStateChange2(s)
            }
            TriStateCheckbox(
                state = parentState,
                onClick = onParentClick,
                colors = CheckboxDefaults.colors(checkedColor = MaterialTheme.colors.primary)
            )
            Row(modifier = Modifier.padding(10.dp, 0.dp, 0.dp, 10.dp)) {
                Checkbox(checked = state, onCheckedChange = onStateChange)
                Checkbox(checked = state2, onCheckedChange = onStateChange2)
    
            }
    
            val switchCheckedState = remember {
                mutableStateOf(true)
            }
            Switch(
                checked = switchCheckedState.value,
                onCheckedChange = { switchCheckedState.value = it },
                colors = SwitchDefaults.colors(
                    checkedThumbColor = Color.Cyan, checkedTrackColor = Color.Gray
                )
            )
    
            var sliderPosition by remember {
                mutableStateOf(0f)
            }
            Text(
                text = "%.1f".format(sliderPosition * 100) + "%",
                modifier = Modifier.align(alignment = CenterHorizontally)
            )
            Slider(value = sliderPosition, onValueChange = { sliderPosition = it })
    
        }
    
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62

    对话框组件

    @Composable
    fun TestDialog() {
        Column {
            val openDialog = remember {
                mutableStateOf(false)
            }
    
            Button(onClick = {
                openDialog.value = !openDialog.value
            }) {
                Text(
                    text = if (openDialog.value) "CloseDialog" else {
                        "OpenDialog"
                    }
                )
            }
    
            if (openDialog.value) {
                Dialog(
                    onDismissRequest = { openDialog.value = false }, properties = DialogProperties(
                        dismissOnBackPress = true, dismissOnClickOutside = true
                    )
                ) {
                    Box(
                        modifier = Modifier
                            .size(300.dp, 400.dp)
                            .background(Color.White)
                    ) {
                        Button(onClick = {
                            openDialog.value = false
                        }, modifier = Modifier.align(Alignment.Center)) {
                            Text(text = "Close")
                        }
                    }
                }
            }
    
    
            val alertDialog = remember {
                mutableStateOf(false)
            }
    
            Button(onClick = {
                alertDialog.value = !alertDialog.value
            }) {
                Text(
                    text = if (alertDialog.value) "CloseAlertDialog" else {
                        "OpenAlertDialog"
                    }
                )
            }
    
            if (alertDialog.value) {
                AlertDialog(onDismissRequest = { alertDialog.value = false },
                    title = { Text(text = "开启位置服务") },
                    text = {
                        Text(text = "提供精确的位置使用,请务必打开")
                    },
                    confirmButton = {
                        Button(onClick = { alertDialog.value = false }) {
                            Text(text = "同意")
                        }
                    },
                    dismissButton = {
                        TextButton(onClick = { alertDialog.value = false }) {
                            Text(text = "取消")
                        }
                    })
            }
        }
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    • 64
    • 65
    • 66
    • 67
    • 68
    • 69
    • 70
    • 71

    进度条组件

    @Preview
    @Composable
    fun TestProgress() {
        var progress by remember {
            mutableStateOf(0.1f)
        }
    
        val animatedProgress by animateFloatAsState(targetValue = progress, animationSpec = ProgressIndicatorDefaults.ProgressAnimationSpec, label = "progressAnim")
        Column(
            modifier = Modifier
                .padding(10.dp)
                .border(2.dp, color = MaterialTheme.colors.primary),
            horizontalAlignment = Alignment.CenterHorizontally,
            verticalArrangement = Arrangement.Center
        ) {
            CircularProgressIndicator(
                progress = animatedProgress,
                backgroundColor = MaterialTheme.colors.primary.copy(alpha = IndicatorBackgroundOpacity),
            )
            Spacer(modifier = Modifier.height(30.dp))
    
            LinearProgressIndicator(progress = animatedProgress, strokeCap = StrokeCap.Round)
            Spacer(modifier = Modifier.height(30.dp))
            Row {
    
                OutlinedButton(onClick = {
                    if (progress >= 1.0f) {
                        return@OutlinedButton
                    }
                    progress += 0.1f
                }) {
                    Text(text = "增加进度")
                }
                Spacer(modifier = Modifier.width(30.dp))
                OutlinedButton(onClick = {
                    if (progress == 0f) {
                        return@OutlinedButton
                    }
                    progress -= 0.1f
                }) {
                    Text(text = "减少进度")
                }
            }
        }
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45

    常用的布局组件

    ConstraintLayout约束布局需要依赖:implementation “androidx.constraintlayout:constraintlayout-compose: $constraintlayout _version”

    布局

    @Preview
    @Composable
    fun TestLayout() {
    
        Column(
            modifier = Modifier
                .border(2.dp, color = MaterialTheme.colors.primary)
                .verticalScroll(
                    rememberScrollState()
                )
        ) {
            Surface(
                shape = RoundedCornerShape(8.dp),
                modifier = Modifier
                    .padding(horizontal = 12.dp, vertical = 10.dp)
                    .fillMaxWidth(),
                elevation = 10.dp
            ) {
                Column(modifier = Modifier.padding(12.dp)) {
                    Text(text = "Jetpack Compose是什么", style = MaterialTheme.typography.h6)
                    Spacer(modifier = Modifier.padding(vertical = 5.dp))
                    Text(
                        text = "Jetpack Compose是用于构建原生Android UI的现代工具包。它采用声明式UI的设计,拥有更简单的自定义和实时的交互预览功能,由Android官方团队全新打造的UI框架。Jetpack Compose可简化并加快Android上的界面开发,使用更少的代码、强大的工具和直观的Kotlin API,快速打造生动而精彩的应用。"
                    )
                    Row(
                        modifier = Modifier.fillMaxWidth(),
                        horizontalArrangement = Arrangement.SpaceBetween
                    ) {
                        IconButton(onClick = { /*TODO*/ }) {
                            Icon(Icons.Filled.Favorite, null)
                        }
                        IconButton(onClick = { /*TODO*/ }) {
                            Icon(Icons.Filled.Add, null)
                        }
                        IconButton(onClick = { /*TODO*/ }) {
                            Icon(Icons.Filled.Star, null)
                        }
                    }
    
                }
            }
    
            Spacer(modifier = Modifier.height(40.dp))
            Text(text = "约束布局")
            Spacer(modifier = Modifier.height(40.dp))
    
            ConstraintLayout(
                modifier = Modifier
                    .width(300.dp)
                    .height(100.dp)
                    .padding(10.dp)
            ) {
                val (portraitImageRef, usernameTextRef, desTextRef) = remember {
                    createRefs()//createRefs最多创建16个引用
                }
                Image(painter = painterResource(id = R.drawable.img),
                    contentDescription = "",
                    modifier = Modifier.constrainAs(portraitImageRef) {
                        top.linkTo(parent.top)
                        start.linkTo(parent.start)
                        bottom.linkTo(parent.bottom)
                    })
                Text(text = "舞蹈系学姐",
                    style = MaterialTheme.typography.h6,
                    modifier = Modifier.constrainAs(usernameTextRef) {
                        top.linkTo(portraitImageRef.top)
                        start.linkTo(portraitImageRef.end, 10.dp)
                    })
                Text(text = "一本非常好看的漫画",
                    style = MaterialTheme.typography.body1,
                    modifier = Modifier.constrainAs(desTextRef) {
                        top.linkTo(usernameTextRef.bottom, 10.dp)
                        start.linkTo(usernameTextRef.start)
                    })
            }
    
            Spacer(modifier = Modifier.height(40.dp))
    
            ConstraintLayout(
                modifier = Modifier
                    .width(300.dp)
                    .height(100.dp)
                    .padding(10.dp)
            ) {
                val (usernameTextRef, passwordTextRef, usernameInputRef, passwordInputRef, dividerRef) = remember {
                    createRefs()//createRefs最多创建16个引用
                }
                val barrier = createEndBarrier(usernameTextRef, passwordTextRef)
    
                Text(text = "用户名", modifier = Modifier.constrainAs(usernameTextRef) {
                    top.linkTo(parent.top)
                    start.linkTo(parent.start)
                })
    
                Divider(
                    Modifier
                        .fillMaxWidth()
                        .constrainAs(dividerRef) {
                            top.linkTo(usernameTextRef.bottom)
                            bottom.linkTo(passwordTextRef.top)
    
                        })
    
                Text(text = "密码", modifier = Modifier.constrainAs(passwordTextRef) {
                    top.linkTo(usernameTextRef.bottom, 19.dp)
                    start.linkTo(parent.start)
                })
                OutlinedTextField(value = "456546461",
                    onValueChange = {},
                    modifier = Modifier.constrainAs(usernameInputRef) {
                        start.linkTo(barrier, 10.dp)
                        top.linkTo(usernameTextRef.top)
                        bottom.linkTo(usernameTextRef.bottom)
                        height = Dimension.fillToConstraints
                    })
    
    
                OutlinedTextField(value = "4645136131",
                    onValueChange = {},
                    modifier = Modifier.constrainAs(passwordInputRef) {
                        start.linkTo(barrier, 10.dp)
                        top.linkTo(passwordTextRef.top)
                        bottom.linkTo(passwordTextRef.bottom)
                        height = Dimension.fillToConstraints
                    })
    
            }
    
            Spacer(modifier = Modifier.height(20.dp))
    
            ConstraintLayout(
                modifier = Modifier
                    .fillMaxWidth()
                    .height(200.dp)
                    .padding(10.dp)
                    .background(Color.Gray)
            ) {
                val (backgroundRef, avatarRef, textRef) = remember {
                    createRefs()
                }
    
                val guideLine = createGuidelineFromTop(0.4f)
                Box(modifier = Modifier
                    .constrainAs(backgroundRef) {
                        top.linkTo(parent.top)
                        bottom.linkTo(guideLine)
                        width = Dimension.matchParent
                        height = Dimension.fillToConstraints
                    }
                    .background(Color(0xFF1E9FFF)))
    
                Image(painter = painterResource(id = R.drawable.avatar),
                    contentDescription = "",
                    modifier = Modifier.constrainAs(avatarRef) {
                        top.linkTo(guideLine)
                        bottom.linkTo(guideLine)
                        start.linkTo(parent.start)
                        end.linkTo(parent.end)
                    })
                Text(text = "排雷数码港", color = Color.White, modifier = Modifier.constrainAs(textRef) {
                    top.linkTo(avatarRef.bottom, 10.dp)
                    start.linkTo(parent.start)
                    end.linkTo(parent.end)
                })
    
            }
    
            Spacer(modifier = Modifier.height(20.dp))
            ConstraintLayout(
                modifier = Modifier
                    .fillMaxWidth()
                    .height(200.dp)
                    .padding(10.dp)
                    .background(Color.Gray)
            ) {
                val (text1Ref, text2Ref, text3Ref, text4Ref) = remember {
                    createRefs()
                }
                /*createVerticalChain(
                    text1Ref, text2Ref, text3Ref, text4Ref, chainStyle = ChainStyle.Spread
                )*/
                /*createVerticalChain(
                    text1Ref, text2Ref, text3Ref, text4Ref, chainStyle = ChainStyle.Packed
                )*/
                createVerticalChain(
                    text1Ref, text2Ref, text3Ref, text4Ref, chainStyle = ChainStyle.SpreadInside
                )
                Text(text = "text1", modifier = Modifier.constrainAs(text1Ref) {
                    start.linkTo(parent.start)
                    end.linkTo(parent.end)
                })
    
                Text(text = "text2", modifier = Modifier.constrainAs(text2Ref) {
                    start.linkTo(parent.start)
                    end.linkTo(parent.end)
                })
                Text(text = "text3", modifier = Modifier.constrainAs(text3Ref) {
                    start.linkTo(parent.start)
                    end.linkTo(parent.end)
                })
                Text(text = "text4", modifier = Modifier.constrainAs(text4Ref) {
                    start.linkTo(parent.start)
                    end.linkTo(parent.end)
                })
            }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52
    • 53
    • 54
    • 55
    • 56
    • 57
    • 58
    • 59
    • 60
    • 61
    • 62
    • 63
    • 64
    • 65
    • 66
    • 67
    • 68
    • 69
    • 70
    • 71
    • 72
    • 73
    • 74
    • 75
    • 76
    • 77
    • 78
    • 79
    • 80
    • 81
    • 82
    • 83
    • 84
    • 85
    • 86
    • 87
    • 88
    • 89
    • 90
    • 91
    • 92
    • 93
    • 94
    • 95
    • 96
    • 97
    • 98
    • 99
    • 100
    • 101
    • 102
    • 103
    • 104
    • 105
    • 106
    • 107
    • 108
    • 109
    • 110
    • 111
    • 112
    • 113
    • 114
    • 115
    • 116
    • 117
    • 118
    • 119
    • 120
    • 121
    • 122
    • 123
    • 124
    • 125
    • 126
    • 127
    • 128
    • 129
    • 130
    • 131
    • 132
    • 133
    • 134
    • 135
    • 136
    • 137
    • 138
    • 139
    • 140
    • 141
    • 142
    • 143
    • 144
    • 145
    • 146
    • 147
    • 148
    • 149
    • 150
    • 151
    • 152
    • 153
    • 154
    • 155
    • 156
    • 157
    • 158
    • 159
    • 160
    • 161
    • 162
    • 163
    • 164
    • 165
    • 166
    • 167
    • 168
    • 169
    • 170
    • 171
    • 172
    • 173
    • 174
    • 175
    • 176
    • 177
    • 178
    • 179
    • 180
    • 181
    • 182
    • 183
    • 184
    • 185
    • 186
    • 187
    • 188
    • 189
    • 190
    • 191
    • 192
    • 193
    • 194
    • 195
    • 196
    • 197
    • 198
    • 199
    • 200
    • 201
    • 202
    • 203
    • 204
    • 205

    Scaffold脚手架

    data class Item(val name: String, val icon: Int)
    
    @SuppressLint("UnusedMaterialScaffoldPaddingParameter")
    @Composable
    fun TestScaffold() {
    
        val selectedItem by remember {
            mutableStateOf(0)
        }
        val items = listOf<Item>(
            Item("主页", R.drawable.home),
            Item("列表", R.drawable.list),
            Item("设置", R.drawable.setting)
        )
    
        val scaffoldState = rememberScaffoldState()
        val scope = rememberCoroutineScope()
    
        Scaffold(topBar = {
            TopAppBar(title = { Text(text = "主页") }, navigationIcon = {
                IconButton(
                    onClick = {
                        scope.launch {
                            scaffoldState.drawerState.open()
                        }
                    },
                ) {
                    Icon(Icons.Filled.Menu, contentDescription = "")
                }
            })
        }, bottomBar = {
            BottomNavigation {
                items.forEachIndexed { index, item ->
                    BottomNavigationItem(selected = selectedItem == index, onClick = { }, icon = {
                        Icon(
                            painter = painterResource(id = item.icon), contentDescription = item.name
                        )
                    }, alwaysShowLabel = false, label = { Text(text = item.name) })
                }
            }
        }, drawerContent = { Text(text = "侧边栏") }, scaffoldState = scaffoldState) {
            Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
                Text(text = "主页界面")
            }
    
        }
        BackHandler(enabled = scaffoldState.drawerState.isOpen) {
            scope.launch {
                scaffoldState.drawerState.close()
            }
        }
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28
    • 29
    • 30
    • 31
    • 32
    • 33
    • 34
    • 35
    • 36
    • 37
    • 38
    • 39
    • 40
    • 41
    • 42
    • 43
    • 44
    • 45
    • 46
    • 47
    • 48
    • 49
    • 50
    • 51
    • 52

    列表

    @Preview
    @Composable
    fun TestList() {
        LazyColumn(
            modifier = Modifier
                .fillMaxSize()
                .background(Color.Gray),
            contentPadding = PaddingValues(35.dp),
            verticalArrangement = Arrangement.spacedBy(10.dp)
        ) {
            items((1..50).toList()) { index ->
                ContentCard(index = index)
            }
        }
    }
    
    @Composable
    fun ContentCard(index: Int) {
        Card(elevation = 8.dp, modifier = Modifier.fillMaxWidth()) {
            Box(
                modifier = Modifier
                    .fillMaxSize()
                    .padding(15.dp), contentAlignment = Alignment.Center
            ) {
                Text(text = "第${index}卡片", style = MaterialTheme.typography.h5)
            }
        }
    }
    
    • 1
    • 2
    • 3
    • 4
    • 5
    • 6
    • 7
    • 8
    • 9
    • 10
    • 11
    • 12
    • 13
    • 14
    • 15
    • 16
    • 17
    • 18
    • 19
    • 20
    • 21
    • 22
    • 23
    • 24
    • 25
    • 26
    • 27
    • 28

    《Jetpack Compose从入门到实战》第一章 全新的 Android UI 框架

    《Jetpack Compose从入门到实战》 第二章 了解常用UI组件

    《Jetpack Compose从入门到实战》第三章 定制 UI 视图

    《Jetpack Compose从入门到实战》第八章 Compose页面 导航

    《Jetpack Compose从入门到实战》第九章 Accompanist 与第三方组件库

  • 相关阅读:
    苹果macOS电脑版 植物大战僵尸游戏
    【SpringBoot】SpringBoot整合Mybatis、druid
    一本通1059;求平均年龄
    深度学习(三)之LSTM写诗
    pytorch单精度、半精度、混合精度、单卡、多卡(DP / DDP)、FSDP、DeepSpeed模型训练
    uniapp 测试 app 到安卓模拟器部署方法以及常见错误解决 无废话
    River Locks
    【MySQL从入门到精通】【高级篇】(六)MySQL表的存储引擎,InnoDB与MyISAM的对比
    解决 confluent-kafka-go 在windows下未定义的引用 __imp__wassert 错误
    UE4 Android端使用MediaPlayer注意事项
  • 原文地址:https://blog.csdn.net/qq_61735602/article/details/133415303