compose的TextField等组件请求焦点和释放焦点

最新推荐文章于 2025-04-26 22:23:04 发布

原创最新推荐文章于 2025-04-26 22:23:04 发布 · 4k 阅读

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文章标签：

#android #jetpack

本文介绍了如何在Android的Jetpack Compose中管理TextField的焦点，包括如何请求焦点和释放焦点。通过创建FocusRequester和FocusManager对象，并在适当位置调用相应方法，可以实现对输入组件焦点的有效控制。

请求焦点

首先是创建一个FocusRequester对象

val focusRequester = remember { FocusRequester() }

在需要请求焦点的地方调用

focusRequester.requestFocus()

最后，调用Modifier的focusRequester方法即可

Modifier.focusRequester(focusRequester)

示例

val focusRequester = remember { FocusRequester() }
var color by remember { mutableStateOf(Black) }
Box(
    Modifier
        .clickable { focusRequester.requestFocus() }
        .border(2.dp, color)
        // The focusRequester should be added BEFORE the focusable.
        .focusRequester(focusRequester)
        // The onFocusChanged should be added BEFORE the focusable that is being observed.
        .onFocusChanged { color = if (it.isFocused) Green else Black }
        .focusable()
)

释放焦点

首先是在当前的组件下创建一个FocusManager对象

val focusManager = LocalFocusManager.current

然后再需要释放焦点的地方调用该方法即可

focusManager.clearFocus()

示例

val focusManager = LocalFocusManager.current
Column(Modifier.clickable { focusManager.clearFocus() }) {
    Box(Modifier.focusable().size(100.dp))
    Box(Modifier.focusable().size(100.dp))
    Box(Modifier.focusable().size(100.dp))
}