Android系统中是否有一种方法可以检测软件(也就是Android。“软”)键盘在屏幕上可见吗?
当前回答
There is a direct method to find this out. And, it does not require the layout changes. So it works in immersive fullscreen mode, too. But, unfortunately, it does not work on all devices. So you have to test it with your device(s). The trick is that you try to hide or show the soft keyboard and capture the result of that try. If it works correct then the keyboard is not really shown or hidden. We just ask for the state. To stay up-to-date, you simply repeat this operation, e.g. every 200 milliseconds, using a Handler. The implementation below does just a single check. If you do multiple checks, then you should enable all the (_keyboardVisible) tests.
public interface OnKeyboardShowHide
{
void onShowKeyboard( Object param );
void onHideKeyboard( Object param );
}
private static Handler _keyboardHandler = new Handler();
private boolean _keyboardVisible = false;
private OnKeyboardShowHide _keyboardCallback;
private Object _keyboardCallbackParam;
public void start( OnKeyboardShowHide callback, Object callbackParam )
{
_keyboardCallback = callback;
_keyboardCallbackParam = callbackParam;
//
View view = getCurrentFocus();
if (view != null)
{
InputMethodManager imm = (InputMethodManager) getSystemService( Activity.INPUT_METHOD_SERVICE );
imm.hideSoftInputFromWindow( view.getWindowToken(), InputMethodManager.HIDE_IMPLICIT_ONLY, _keyboardResultReceiver );
imm.showSoftInput( view, InputMethodManager.SHOW_IMPLICIT, _keyboardResultReceiver );
}
else // if (_keyboardVisible)
{
_keyboardVisible = false;
_keyboardCallback.onHideKeyboard( _keyboardCallbackParam );
}
}
private ResultReceiver _keyboardResultReceiver = new ResultReceiver( _keyboardHandler )
{
@Override
protected void onReceiveResult( int resultCode, Bundle resultData )
{
switch (resultCode)
{
case InputMethodManager.RESULT_SHOWN :
case InputMethodManager.RESULT_UNCHANGED_SHOWN :
// if (!_keyboardVisible)
{
_keyboardVisible = true;
_keyboardCallback.onShowKeyboard( _keyboardCallbackParam );
}
break;
case InputMethodManager.RESULT_HIDDEN :
case InputMethodManager.RESULT_UNCHANGED_HIDDEN :
// if (_keyboardVisible)
{
_keyboardVisible = false;
_keyboardCallback.onHideKeyboard( _keyboardCallbackParam );
}
break;
}
}
};
其他回答
可以使用showSoftInput()和hideSoftInput()的回调结果来检查键盘的状态。完整的细节和示例代码在
https://rogerkeays.com/how-to-check-if-the-software-keyboard-is-shown-in-android
它使用活动的adjustNothing标志和使用生命周期事件。还有Kotlin:
/**
* This class uses a PopupWindow to calculate the window height when the floating keyboard is opened and closed
*
* @param activity The parent activity
* The root activity that uses this KeyboardManager
*/
class KeyboardManager(private val activity: AppCompatActivity) : PopupWindow(activity), LifecycleObserver {
private var observerList = mutableListOf<((keyboardTop: Int) -> Unit)>()
/** The last value of keyboardTop */
private var keyboardTop: Int = 0
/** The view that is used to calculate the keyboard top */
private val popupView: View?
/** The parent view */
private var parentView: View
var isKeyboardShown = false
private set
/**
* Create transparent view which will be stretched over to the full screen
*/
private fun createFullScreenView(): View {
val view = LinearLayout(activity)
view.layoutParams = LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT)
view.background = ColorDrawable(Color.TRANSPARENT)
return view
}
init {
this.popupView = createFullScreenView()
contentView = popupView
softInputMode = LayoutParams.SOFT_INPUT_ADJUST_RESIZE or LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE
inputMethodMode = INPUT_METHOD_NEEDED
parentView = activity.findViewById(android.R.id.content)
width = 0
height = LayoutParams.MATCH_PARENT
popupView.viewTreeObserver.addOnGlobalLayoutListener {
val rect = Rect()
popupView.getWindowVisibleDisplayFrame(rect)
val keyboardTop = rect.bottom
if (this.keyboardTop != keyboardTop) {
isKeyboardShown = keyboardTop < this.keyboardTop
this.keyboardTop = keyboardTop
observerList.forEach { it(keyboardTop) }
}
}
activity.lifecycle.addObserver(this)
}
/**
* This must be called after the onResume of the Activity or inside view.post { } .
* PopupWindows are not allowed to be registered before the onResume has finished
* of the Activity
*/
@OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
fun start() {
parentView.post {
if (!isShowing && parentView.windowToken != null) {
setBackgroundDrawable(ColorDrawable(0))
showAtLocation(parentView, Gravity.NO_GRAVITY, 0, 0)
}
}
}
/**
* This manager will not be used anymore
*/
@OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
fun close() {
activity.lifecycle.removeObserver(this)
observerList.clear()
dismiss()
}
/**
* Set the keyboard top observer. The observer will be notified when the keyboard top has changed.
* For example when the keyboard is opened or closed
*
* @param observer The observer to be added to this provider
*/
fun registerKeyboardTopObserver(observer: (keyboardTop: Int) -> Unit) {
observerList.add(observer)
}
}
有用的方法,保持视图始终高于键盘
fun KeyboardManager.updateBottomMarginIfKeyboardShown(
view: View,
activity: AppCompatActivity,
// marginBottom of view when keyboard is hide
marginBottomHideKeyboard: Int,
// marginBottom of view when keybouard is shown
marginBottomShowKeyboard: Int
) {
registerKeyboardTopObserver { bottomKeyboard ->
val bottomView = ViewUtils.getFullViewBounds(view).bottom
val maxHeight = ScreenUtils.getFullScreenSize(activity.windowManager).y
// Check that view is within the window size
if (bottomView < maxHeight) {
if (bottomKeyboard < bottomView) {
ViewUtils.updateMargin(view, bottomMargin = bottomView - bottomKeyboard +
view.marginBottom + marginBottomShowKeyboard)
} else ViewUtils.updateMargin(view, bottomMargin = marginBottomHideKeyboard)
}
}
}
在getFullViewBounds
fun getLocationOnScreen(view: View): Point {
val location = IntArray(2)
view.getLocationOnScreen(location)
return Point(location[0], location[1])
}
fun getFullViewBounds(view: View): Rect {
val location = getLocationOnScreen(view)
return Rect(location.x, location.y, location.x + view.width,
location.y + view.height)
}
在getFullScreenSize
fun getFullScreenSize(wm: WindowManager? = null) =
getScreenSize(wm) { getRealSize(it) }
private fun getScreenSize(wm: WindowManager? = null, block: Display.(Point) -> Unit): Point {
val windowManager = wm ?: App.INSTANCE.getSystemService(Context.WINDOW_SERVICE)
as WindowManager
val point = Point()
windowManager.defaultDisplay.block(point)
return point
}
其中更新边距
fun updateMargin(
view: View,
leftMargin: Int? = null,
topMargin: Int? = null,
rightMargin: Int? = null,
bottomMargin: Int? = null
) {
val layoutParams = view.layoutParams as ViewGroup.MarginLayoutParams
if (leftMargin != null) layoutParams.leftMargin = leftMargin
if (topMargin != null) layoutParams.topMargin = topMargin
if (rightMargin != null) layoutParams.rightMargin = rightMargin
if (bottomMargin != null) layoutParams.bottomMargin = bottomMargin
view.layoutParams = layoutParams
}
我创建了一个可以用于此目的的简单类:https://github.com/ravindu1024/android-keyboardlistener。只需将其复制到您的项目中,并按如下方式使用:
KeyboardUtils.addKeyboardToggleListener(this, new KeyboardUtils.SoftKeyboardToggleListener()
{
@Override
public void onToggleSoftKeyboard(boolean isVisible)
{
Log.d("keyboard", "keyboard visible: "+isVisible);
}
});
这是如何在一个片段中使用软键盘状态监听器(适用于API 21及以上)
private var currentWindowInsets: WindowInsetsCompat = WindowInsetsCompat.Builder().build()
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
setWindowInsetsAnimationCallback(requireView().rootView, object : Callback(DISPATCH_MODE_CONTINUE_ON_SUBTREE) {
override fun onProgress(insets: WindowInsetsCompat, runningAnimations: MutableList<WindowInsetsAnimationCompat>): WindowInsetsCompat {
currentWindowInsets = insets
return insets
}
override fun onEnd(animation: WindowInsetsAnimationCompat) {
super.onEnd(animation)
val keyboardIsVisible = currentWindowInsets.isVisible(WindowInsetsCompat.Type.ime())
if (keyboardIsVisible) { //do your stuff }
}
})
}
如你所知,android软件的键盘只有在有可能的输入事件时才可见。换句话说,只有当EditText被聚焦时,键盘才可见。这意味着你可以通过使用OnFocusChangeListener获得键盘是否可见。
//Declare this Globally
public boolean isKeyBoardVisible = false;
//In OnCreate *[For Activity]*, OnCreateView *[For Fragment]*
text_send.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
if(hasFocus)
isKeyBoardVisible = true;
else
isKeyBoardVisible = false;
}
});
现在你可以在类的任何地方使用isKeyBoardVisible变量来获取键盘是否打开。这对我来说很有效。
注意:当使用InputMethodManager以编程方式打开键盘时,这个过程不起作用,因为它不调用OnFocusChangeListener。
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