在Jetpack Compose中检测键盘的打开和关闭可以通过使用Android的软键盘可见性监听器来实现。下面是一个示例代码:
import androidx.compose.runtime.*
import androidx.compose.ui.platform.LocalLifecycleOwner
import androidx.compose.ui.platform.LocalView
import androidx.compose.ui.viewinterop.AndroidView
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleEventObserver
import androidx.lifecycle.LifecycleOwner
@Composable
fun KeyboardVisibilityDetector(onKeyboardVisibilityChanged: (Boolean) -> Unit) {
val view = LocalView.current
val lifecycleOwner = LocalLifecycleOwner.current
AndroidView(
factory = { context ->
View(context).apply {
viewTreeObserver.addOnGlobalLayoutListener {
val rect = Rect()
getWindowVisibleDisplayFrame(rect)
val screenHeight = rootView.height
val keyboardHeight = screenHeight - rect.bottom
val isOpen = keyboardHeight > screenHeight * 0.15 // 判断键盘是否打开
onKeyboardVisibilityChanged(isOpen)
}
}
},
update = { view ->
val lifecycleObserver = object : LifecycleEventObserver {
override fun onStateChanged(source: LifecycleOwner, event: Lifecycle.Event) {
if (event == Lifecycle.Event.ON_DESTROY) {
view.viewTreeObserver.removeOnGlobalLayoutListener(null)
lifecycleOwner.lifecycle.removeObserver(this)
}
}
}
view.viewTreeObserver.addOnGlobalLayoutListener(null)
lifecycleOwner.lifecycle.addObserver(lifecycleObserver)
}
)
}
使用上述代码,你可以在Compose中创建一个KeyboardVisibilityDetector
组件,并通过onKeyboardVisibilityChanged
回调函数获取键盘的打开和关闭状态。例如:
@Composable
fun MyScreen() {
var isKeyboardVisible by remember { mutableStateOf(false) }
KeyboardVisibilityDetector { isVisible ->
isKeyboardVisible = isVisible
}
// 在这里根据键盘的打开和关闭状态进行相应的布局和逻辑处理
if (isKeyboardVisible) {
// 键盘打开时的布局
} else {
// 键盘关闭时的布局
}
}
这样,当键盘状态发生变化时,isKeyboardVisible
的值会更新,从而触发Compose重新绘制界面。你可以根据键盘的打开和关闭状态来动态调整界面布局和逻辑。
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