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
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
其他回答
而不是假设差异编码,我做了这样的事情,因为我在我的应用程序中有菜单选项。
final View root= findViewById(R.id.myrootview);
root.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
int heightDiff = root.getRootView().getHeight() - root.getHeight();
Rect rectgle= new Rect();
Window window= getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectgle);
int contentViewTop=
window.findViewById(Window.ID_ANDROID_CONTENT).getTop();
if(heightDiff <= contentViewTop){
//Soft KeyBoard Hidden
}else{
//Soft KeyBoard Shown
}
}
});
就计算机而言,这是永远的问题,但这个问题仍然令人难以置信地相关! 所以我把上面的答案结合起来,做了一些改进……
public interface OnKeyboardVisibilityListener {
void onVisibilityChanged(boolean visible);
}
public final void setKeyboardListener(final OnKeyboardVisibilityListener listener) {
final View activityRootView = ((ViewGroup) getActivity().findViewById(android.R.id.content)).getChildAt(0);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
private boolean wasOpened;
private final Rect r = new Rect();
@Override
public void onGlobalLayout() {
activityRootView.getWindowVisibleDisplayFrame(r);
int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
boolean isOpen = heightDiff > 100;
if (isOpen == wasOpened) {
logDebug("Ignoring global layout change...");
return;
}
wasOpened = isOpen;
listener.onVisibilityChanged(isOpen);
}
});
}
这对我很管用。
有一种直接的方法可以找出答案。而且,它不需要任何布局更改。 所以,它也可以在沉浸式全屏模式下工作。 诀窍在于,您尝试隐藏或显示软键盘,并捕获尝试的结果。 没有恐慌,这并不真正显示或隐藏键盘。我们只要求状态。 为了保持最新,您可以简单地重复操作,例如,每200毫秒,使用处理器。 您可以在这里找到一个实现:https://stackoverflow.com/a/27567074/2525452
参考@TacB0sS的回答,我在Kotlin中开发了一个类。希望这对你有所帮助。如果需要改进,请告诉我。
class KeyboardVisibilityObserver(val layRootContainer: View?, val keyboardVisibilityListener: KeyboardVisibilityListener?) {
var isKeyboardOpen = false
private set
private var keyBoardObserver = object : ViewTreeObserver.OnGlobalLayoutListener {
private val DefaultKeyboardDP = 100
// Lollipop includes button bar in the root. Add height of button bar (48dp) to maxDiff
private val EstimatedKeyboardDP = DefaultKeyboardDP + if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) 48 else 0
private val r = Rect()
override fun onGlobalLayout() {
if (layRootContainer != null) {
// Convert the dp to pixels.
val estimatedKeyboardHeight = TypedValue
.applyDimension(TypedValue.COMPLEX_UNIT_DIP, EstimatedKeyboardDP.toFloat(), layRootContainer.resources.displayMetrics).toInt()
// Conclude whether the keyboard is shown or not.
layRootContainer.getWindowVisibleDisplayFrame(r)
val heightDiff = layRootContainer.rootView.height - (r.bottom - r.top)
val isShown = heightDiff >= estimatedKeyboardHeight
if (isShown == isKeyboardOpen) {
// Log.d("Keyboard state", "Ignoring global layout change...");
return
}
isKeyboardOpen = isShown
keyboardVisibilityListener?.onKeyboardVisibilityChanged(isKeyboardOpen)
}
}
}
init {
layRootContainer?.viewTreeObserver?.addOnGlobalLayoutListener(keyBoardObserver)
}
// call this in onDestroy
fun removeObserver(){
layRootContainer?.viewTreeObserver?.removeOnGlobalLayoutListener(keyBoardObserver)
}
interface KeyboardVisibilityListener {
fun onKeyboardVisibilityChanged(isKeyboardOpen: Boolean)
}
}
我知道如何准确地确定键盘是否隐藏。
public int getStatusBarHeight() {
int result = 0;
int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
if (resourceId > 0) {
result = getResources().getDimensionPixelSize(resourceId);
}
return result;
}
public int getNavigationBarHeight() {
int result = 0;
int resourceId = getResources().getIdentifier("navigation_bar_height", "dimen", "android");
if (resourceId > 0) {
result = getResources().getDimensionPixelSize(resourceId);
}
return result;
}
public boolean isKeyboardHidden() {
int delta = mRootView.getRootView().getHeight() - mRootView.getHeight() - getNavigationBarHeight() - getStatusBarHeight()
- getSupportActionBar().getHeight();
return delta <= 0;
}
这适用于平板电脑。当导航栏水平显示时。
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