我需要做一件非常简单的事情-找出软件键盘是否显示。这在Android中可行吗?
当前回答
一个不需要LayoutListener的方法
在我的情况下,我想在替换我的片段之前保存键盘的状态。我调用方法hideSoftInputFromWindow from onSaveInstanceState,它会关闭键盘并返回键盘是否可见。
这个方法很简单,但可能会改变键盘的状态。
其他回答
希望这能帮助到大家。
Reuben Scratton给出的新答案非常棒,而且非常有效,但它只在你将windowSoftInputMode设置为adjuststresize时才有效。如果你将它设置为adjustPan,使用他的代码片段仍然无法检测键盘是否可见。为了解决这个问题,我对上面的代码做了微小的修改。
final View activityRootView = findViewById(R.id.activityRoot);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
Rect r = new Rect();
//r will be populated with the coordinates of your view that area still visible.
activityRootView.getWindowVisibleDisplayFrame(r);
int heightDiff = activityRootView.getRootView().getHeight() - r.height();
if (heightDiff > 0.25*activityRootView.getRootView().getHeight()) { // if more than 25% of the screen, its probably a keyboard...
... do something here
}
}
});
有一个隐藏的方法可以帮助这个,inputmethodmanager。getinputmethodwindowvisibleheight。但我不知道为什么要藏起来。
import android.content.Context
import android.os.Handler
import android.view.inputmethod.InputMethodManager
class SoftKeyboardStateWatcher(private val ctx: Context) {
companion object {
private const val DELAY = 10L
}
private val handler = Handler()
private var isSoftKeyboardOpened: Boolean = false
private val height: Int
get() {
val imm = ctx.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
val method = imm.javaClass.getMethod("getInputMethodWindowVisibleHeight")
method.isAccessible = true
return method.invoke(imm) as Int
}
private val task: Runnable by lazy {
Runnable {
start()
if (!isSoftKeyboardOpened && height > 0) {
isSoftKeyboardOpened = true
notifyOnSoftKeyboardOpened(height)
} else if (isSoftKeyboardOpened && height == 0) {
isSoftKeyboardOpened = false
notifyOnSoftKeyboardClosed()
}
}
}
var listener: SoftKeyboardStateListener? = null
interface SoftKeyboardStateListener {
fun onSoftKeyboardOpened(keyboardHeightInPx: Int)
fun onSoftKeyboardClosed()
}
fun start() {
handler.postDelayed(task, DELAY)
}
fun stop() {
handler.postDelayed({
if (!isSoftKeyboardOpened) handler.removeCallbacks(task)
}, DELAY * 10)
}
private fun notifyOnSoftKeyboardOpened(keyboardHeightInPx: Int) {
listener?.onSoftKeyboardOpened(keyboardHeightInPx)
}
private fun notifyOnSoftKeyboardClosed() {
listener?.onSoftKeyboardClosed()
}
}
if (keyopen())
{
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY,0);
}
上面的函数是我用来检查键盘是否可见的。如果是,那我就关上。
下面显示了所需的两种方法。
首先,在onCreate中定义可工作的窗口高度。
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// add to onCreate method
Rect rectgle= new Rect();
Window window= getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
sheight= rectgle.bottom;
//
}
然后,添加一个布尔方法来获取该实例的窗口高度。如果它与原来的不匹配(假设您没有在此过程中更改它……),那么键盘是打开的。
public boolean keyopen()
{
Rect rectgle= new Rect();
Window window= getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
int curheight= rectgle.bottom;
if (curheight!=sheight)
{
return true;
}
else
{
return false;
}
}
Frotz !
检查元素的高度是不可靠的,因为一些键盘,如WifiKeyboard的高度为零。
相反,您可以使用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
我的答案基本上与Kachi的答案相同,但我将它包装到一个很好的helper类中,以清理它在整个应用程序中的使用方式。
import android.app.Activity;
import android.app.Fragment;
import android.graphics.Rect;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
/**
* Detects Keyboard Status changes and fires events only once for each change
*/
public class KeyboardStatusDetector {
KeyboardVisibilityListener visibilityListener;
boolean keyboardVisible = false;
public void registerFragment(Fragment f) {
registerView(f.getView());
}
public void registerActivity(Activity a) {
registerView(a.getWindow().getDecorView().findViewById(android.R.id.content));
}
public KeyboardStatusDetector registerView(final View v) {
v.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
Rect r = new Rect();
v.getWindowVisibleDisplayFrame(r);
int heightDiff = v.getRootView().getHeight() - (r.bottom - r.top);
if (heightDiff > 100) { // if more than 100 pixels, its probably a keyboard...
/** Check this variable to debounce layout events */
if(!keyboardVisible) {
keyboardVisible = true;
if(visibilityListener != null) visibilityListener.onVisibilityChanged(true);
}
} else {
if(keyboardVisible) {
keyboardVisible = false;
if(visibilityListener != null) visibilityListener.onVisibilityChanged(false);
}
}
}
});
return this;
}
public KeyboardStatusDetector setVisibilityListener(KeyboardVisibilityListener listener) {
visibilityListener = listener;
return this;
}
public static interface KeyboardVisibilityListener {
public void onVisibilityChanged(boolean keyboardVisible);
}
}
你可以使用它来检测整个应用程序中的键盘变化,如下所示:
new KeyboardStatusDetector()
.registerFragment(fragment) //register to a fragment
.registerActivity(activity) //or register to an activity
.registerView(view) //or register to a view
.setVisibilityListener(new KeyboardVisibilityListener() {
@Override
public void onVisibilityChanged(boolean keyboardVisible) {
if(keyboardVisible) {
//Do stuff for keyboard visible
}else {
//Do stuff for keyboard hidden
}
}
});
注意:只使用一个“寄存器”调用。它们都是一样的,只是为了方便
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