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Jetpack Compose学习 -------- Checkbox 复选框

Checkbox 复选框 基本使用

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@Composable
fun CheckBoxDemo() {
    val checkedState = remember {
        mutableStateOf(true)
    }
    Checkbox(
        checked = checkedState.value,
        onCheckedChange = {
            checkedState.value = it
        }
    )
}

发表于 更新于 分类于 ，

Jetpack Compose学习 -------- Card

Card 卡片 简单使用

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@Composable
 fun CardDemo() {
     Card(
         modifier = Modifier.fillMaxWidth() ,
         backgroundColor = Color.White,
         elevation = 10.dp,
     ) {
         Text(text = "This is a Card Demo",Modifier.padding(10.dp))
     }
 }
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@Composable
fun ComposableSample() {
    Card(
        modifier = Modifier
            .size(200.dp)
            .padding(10.dp),
        //形状 圆角矩形
        shape = RoundedCornerShape(8.dp),
        //背景颜色
        backgroundColor = Color.White,
        //内容的颜色
        contentColor = Color.Black,
        //边框
        border = BorderStroke(0.5.dp, Color.Gray),
        //阴影
        elevation = 10.dp
    ) {
        Column() {
            Image(
                painter = painterResource(id = R.mipmap.icon_header),
                contentDescription = "图片描述",
                contentScale = ContentScale.FillBounds
            )
        }
    }
}

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@Composable
   fun CardDemo() {
       Card(
           modifier = Modifier
               .fillMaxWidth()
               // 外边距
               .padding(15.dp)
               .clickable(
                   // 设置点击波纹效果，注意如果 CardDemo() 函数不在 ExamplesTheme() {} 下调用
                   // 将无法显示波纹效果
                   onClick = {
                       Log.d("Clickable", " clicked.")
                   }),
           backgroundColor = Color.White,
           // 设置阴影
           elevation = 10.dp,
       )
       {
           Column(
               // 内边距
               Modifier.padding(15.dp)
           ) {
               Text(buildAnnotatedString {
                   append("welcome to ")
                   withStyle(
                       style = SpanStyle(
                           color = Color(0xFF4552B8),
                           fontWeight = FontWeight.W900,
                       )
                   ) {
                       append("Jetpack Compose Playground")
                   }
               })
               Text(buildAnnotatedString {
                   append("Now you are in the ")
                   withStyle(
                       style = SpanStyle(
                           fontWeight = FontWeight.W900,
                       )
                   ) {
                       append("Card")
                   }
                   append(" section")
               })
           }
       }
   }

发表于 更新于 分类于 ，

Jetpack Compose学习 -------- Canvas 图形

Canvas 图形 基本属性

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//绘制 线
    @Composable
    fun CanvasDrawLineDemo() {
        //画布
        Canvas(
            //充满整个屏幕
            modifier = Modifier.fillMaxSize()
        ) {
            val canvasWidth = size.width
            val canvasHeight = size.height

            //绘制 线
            drawLine(
                start = Offset(x = canvasWidth, y = 0f),
                end = Offset(x = 0f, y = canvasHeight),
                color = Color.Red
            )
        }
    }

  //绘制 圆
    @Composable
    fun CanvasDrawCircleDemo() {
        //画布
        Canvas(
            //充满整个屏幕
            modifier = Modifier.fillMaxSize()
        ) {
            val canvasWidth = size.width
            val canvasHeight = size.height

            //绘制 圆
            drawCircle(
                color = Color.Red,
                //圆心  画布中心点
                center = Offset(
                    x = canvasWidth / 2,
                    y = canvasHeight / 2
                ),
                //半径 : 画布最小边 的 1/4
                radius = size.minDimension / 4
            )
        }
    }

//绘制 弧
@Composable
fun CanvasDrawArcDemo() {
    //画布
    Canvas(
        //充满整个屏幕
        modifier = Modifier.fillMaxSize()
    ) {
        //绘制 弧
        drawArc(
            color = Color.Red,
            startAngle = 0f,
            sweepAngle = 60f,
            useCenter = true,
            size = Size(300f, 300f),
            topLeft = Offset(60f, 60f)
        )
    }
}

 //绘制 矩形
    @Composable
    fun CanvasDrawRectDemo() {
        //画布
        Canvas(
            //充满整个屏幕
            modifier = Modifier.fillMaxSize()
        ) {
            val canvasQuadrantSize = size / 2f

            //绘制 矩形
            drawRect(
                color = Color.Red,
                size = canvasQuadrantSize
            )
        }
    }


    //绘制 矩形
    @Composable
    fun CanvasInsetDrawRectDemo() {
        //画布
        Canvas(
            //充满整个屏幕
            modifier = Modifier.fillMaxSize()
        ) {
            val canvasQuadrantSize = size / 2f
            //更改绘图边界
            inset(150f, 30f) {
                //绘制 矩形
                drawRect(
                    color = Color.Red,
                    size = canvasQuadrantSize
                )
            }
        }
    }
    
      //绘制 矩形
    @Composable
    fun CanvasDrawRectTopLeftDemo() {
        //画布
        Canvas(
            //充满整个屏幕
            modifier = Modifier.fillMaxSize()
        ) {
            val canvasWidth = size.width
            val canvasHeight = size.height
            val canvasSize = size
            //绘制 矩形
            drawRect(
                color = Color.Red,
                topLeft = Offset(x = canvasWidth / 3f, y = canvasHeight / 3f),
                size = canvasSize / 3f
            )
        }
    }
    
     //绘制 矩形
    @Composable
    fun CanvasRotateDrawRectDemo() {
        //画布
        Canvas(
            //充满整个屏幕
            modifier = Modifier.fillMaxSize()
        ) {
            //旋转 45 度
            rotate(degrees = 45f) {
                val canvasWidth = size.width
                val canvasHeight = size.height
                val canvasSize = size
                //绘制 矩形
                drawRect(
                    color = Color.Red,
                    topLeft = Offset(x = canvasWidth / 3f, y = canvasHeight / 3f),
                    size = canvasSize / 3f
                )
            }
        }
    }
    
    //绘制 矩形
    @Composable
    fun CanvasTransformDrawRectDemo() {
        //画布
        Canvas(
            //充满整个屏幕
            modifier = Modifier.fillMaxSize()
        ) {
            val canvasWidth = size.width
            val canvasHeight = size.height
            val canvasSize = size
            //多种转换
            withTransform({
                //平移
                translate(left = canvasWidth / 5f)
                //旋转 45 度
                rotate(degrees = 45f)
            }) {
                //绘制 矩形
                drawRect(
                    color = Color.Red,
                    topLeft = Offset(x = canvasWidth / 3f, y = canvasHeight / 3f),
                    size = canvasSize / 3f
                )

            }
        }
    }

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Jetpack Compose学习 -------- 按钮 Button , IconButton

Button 按钮 基本使用

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@Composable
fun ButtonSample() {
    Button(
        onClick = {
            Log.d("ButtonSample", "按钮被点击")
        },
        modifier = Modifier.padding(10.dp),
        colors = ButtonDefaults.textButtonColors(backgroundColor = Color.Blue)
    ) {
        Text(text = "按钮", color = Color.White)
    }
}

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@Composable
fun ComposableSample() {
    Button(onClick = { }) {
        Icon(
            imageVector = Icons.Filled.Favorite,
            contentDescription = "喜爱",
            modifier = Modifier.size(ButtonDefaults.IconSize)
        )
        //间隔
        Spacer(modifier = Modifier.size(ButtonDefaults.IconSpacing))
        Text(text = "喜爱")
    }
}

IconButton 图标按钮 基本使用

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@Composable
fun ComposableSample() {
    Row {
        IconButton(onClick = { }) {
            Icon(Icons.Filled.Search, null)
        }

        IconButton(onClick = { }) {
            Icon(Icons.Filled.ArrowBack, null)
        }

        IconButton(onClick = { }) {
            Icon(Icons.Filled.Done, null)
        }
        val isSelected = remember {
            mutableStateOf(false)
        }
        //取消水波纹
        IconButtonNoIndication(onClick = {
            isSelected.value = !isSelected.value
        }) {
            Icon(
                Icons.Filled.Home,
                null,
                tint = if (isSelected.value) {
                    Color.Red
                } else {
                    Color.Gray
                }
            )
        }
    }
}


    /**
     * 去掉水波纹
     */
    @Composable
    fun IconButtonNoIndication(
        onClick: () -> Unit,
        modifier: Modifier = Modifier,
        enabled: Boolean = true,
        interactionSource: MutableInteractionSource = remember { MutableInteractionSource() },
        content: @Composable () -> Unit
    ) {
        Box(
            modifier = modifier
                .clickable(
                    onClick = onClick,
                    enabled = enabled,
                    role = Role.Button,
                    interactionSource = interactionSource,
                    //取消水波纹
                    indication = null
                )
                .then(Modifier.size(48.dp)),
            contentAlignment = Alignment.Center
        ) { content() }
    }

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Jetpack Compose学习 -------- AlertDialog

AlertDialog 提示框 简单使用

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@Composable
fun AlertDialogSample() {
    MaterialTheme {
        Column(
            Modifier
                .fillMaxSize()
                .wrapContentSize(Alignment.Center)
        ) {
            val openDialog = remember {
                mutableStateOf(false)
            }
            Button(onClick = {
                openDialog.value = true
            }) {
                Text(text = "弹出提示框")
            }
            if (openDialog.value) {
                AlertDialog(
                    onDismissRequest = {
                        // 当用户点击对话框以外的地方或者按下系统返回键将会执行的代码
                        openDialog.value = false
                    },
                    title = {
                        Text(text = "提示框标题")
                    },
                    text = {
                        Text(text = "提示框内容")
                    },
                    confirmButton = {
                        Button(onClick = { openDialog.value = false }) {
                            Text(text = "确认按钮")
                        }
                    },
                    dismissButton = {
                        Button(onClick = { openDialog.value = false }) {
                            Text(text = "取消按钮")
                        }
                    })
            }
        }
    }
}

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@Composable
fun AlertDialogSample2() {
    MaterialTheme {
        Column(
            Modifier
                .fillMaxSize()
                .wrapContentSize(Alignment.Center)
        ) {
            val openDialog = remember {
                mutableStateOf(false)
            }
            Button(onClick = {
                openDialog.value = true
            }) {
                Text(text = "弹出提示框")
            }
            if (openDialog.value) {
                AlertDialog(
                    onDismissRequest = {
                        // 当用户点击对话框以外的地方或者按下系统返回键将会执行的代码
                        openDialog.value = false
                    },
                    title = {
                        Text(
                            text = "开启位置服务",
                            fontWeight = FontWeight.W700,
                            style = MaterialTheme.typography.h6
                        )
                    },
                    text = {
                        Text(
                            text = "这将意味着，我们会给您提供精准的位置服务，并且您将接受关于您订阅的位置信息",
                            fontSize = 16.sp
                        )
                    },
                    confirmButton = {
                        TextButton(
                            onClick = {
                                openDialog.value = false
                            },
                        ) {
                            Text(
                                "确认",
                                fontWeight = FontWeight.W700,
                                style = MaterialTheme.typography.button
                            )
                        }
                    },
                    dismissButton = {
                        TextButton(
                            onClick = {
                                openDialog.value = false
                            }
                        ) {
                            Text(
                                "取消",
                                fontWeight = FontWeight.W700,
                                style = MaterialTheme.typography.button
                            )
                        }
                    })
            }
        }
    }
}

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@Composable
  fun AlertDialogSample3() {
      MaterialTheme {
          Column(
              Modifier
                  .fillMaxSize()
                  .wrapContentSize(Alignment.Center)
          ) {
              val openDialog = remember {
                  mutableStateOf(false)
              }
              Button(onClick = {
                  openDialog.value = true
              }) {
                  Text(text = "弹出提示框")
              }
              if (openDialog.value) {
                  AlertDialog(
                      onDismissRequest = {
                          openDialog.value = false
                      },
                      title = {
                          Text(
                              text = "开启位置服务",
                              fontWeight = FontWeight.W700,
                              style = MaterialTheme.typography.h6
                          )
                      },
                      text = {
                          Text(
                              text = "这将意味着，我们会给您提供精准的位置服务，并且您将接受关于您订阅的位置信息",
                              fontSize = 16.sp
                          )
                      },
                      buttons = {
                          Row(
                              modifier = Modifier.padding(all = 8.dp),
                              horizontalArrangement = Arrangement.Center
                          ) {
                              Button(
                                  modifier = Modifier.fillMaxWidth(),
                                  onClick = { openDialog.value = false }
                              ) {
                                  Text("必须接受！")
                              }
                          }
                      }
                  )
              }
          }
      }
  }