Jetpack Compose：选择器组件

一、Checkbox

复选框，代码如下所示：

val checkState = remember { mutableStateOf(false) }
Checkbox(
    checked = checkState.value,
    onCheckedChange = { checkState.value = it}
)

二、TriStateCheckbox

三态选择框，代码如下所示：

// 为 Checkbox 定义状态
val (state, OnStateChange) = remember { mutableStateOf(true) }
val (state2, OnStateChange2) = remember { mutableStateOf(false) }

// 根据 CheckBox 状态来设置 TriStateCheckbox 状态
val parentState = remember(state, state2) {
    if (state && state2) ToggleableState.On
    else if (!state && !state2) ToggleableState.Off
    else ToggleableState.Indeterminate
}

TriStateCheckbox(
    state = parentState,
    onClick = {
        val result = (parentState != ToggleableState.On)
        OnStateChange(result)
        OnStateChange2(result)
    }
)

Column {
    Checkbox(checked = state, onCheckedChange = OnStateChange)
    Checkbox(checked = state2, onCheckedChange = OnStateChange2)
}

三、Switch

单选开关，代码如下所示：

var checkState by remember { mutableStateOf(false) }
Switch(
    checked = checkState,
    onCheckedChange = {
        checkState = it
    }
)

四、Slider

滑动开关，代码如下所示：

var sliderPosition by remember { mutableStateOf(0f) }
Slider(
    value = sliderPosition,
    onValueChange = {
        sliderPosition = it
    }
)