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
试试这个:
final View activityRootView = getWindow().getDecorView().getRootView();
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.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.bottom - r.top);
if (heightDiff < activityRootView.getRootView().getHeight() / 4 ) { // if more than 100 pixels, its probably a keyboard...
// ... do something here ... \\
}
}
});
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 int DefaultKeyboardDP = 100;
// From @nathanielwolf answer... Lollipop includes button bar in the root. Add height of button bar (48dp) to maxDiff
private final int EstimatedKeyboardDP = DefaultKeyboardDP + (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? 48 : 0);
private final Rect r = new Rect();
@Override
public void onGlobalLayout() {
// Convert the dp to pixels.
int estimatedKeyboardHeight = (int) TypedValue
.applyDimension(TypedValue.COMPLEX_UNIT_DIP, EstimatedKeyboardDP, activityRootView.getResources().getDisplayMetrics());
// Conclude whether the keyboard is shown or not.
activityRootView.getWindowVisibleDisplayFrame(r);
int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
boolean isShown = heightDiff >= estimatedKeyboardHeight;
if (isShown == wasOpened) {
Log.d("Keyboard state", "Ignoring global layout change...");
return;
}
wasOpened = isShown;
listener.onVisibilityChanged(isShown);
}
});
}
对我有用:)
注意: 如果你注意到DefaultKeyboardDP不适合你的设备播放的值,并发表评论,让每个人都知道应该是什么值…最终我们将得到适合所有设备的正确值!
要了解更多细节,请查看Cyborg上的实现
也有解决方案与系统嵌入,但它只适用于API >= 21 (Android L)。说你有BottomNavigationView,这是线性布局的孩子,你需要隐藏它时,键盘显示:
> LinearLayout
> ContentView
> BottomNavigationView
你所需要做的就是以这样的方式扩展LinearLayout:
public class KeyboardAwareLinearLayout extends LinearLayout {
public KeyboardAwareLinearLayout(Context context) {
super(context);
}
public KeyboardAwareLinearLayout(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public KeyboardAwareLinearLayout(Context context,
@Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public KeyboardAwareLinearLayout(Context context, AttributeSet attrs,
int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override
public WindowInsets onApplyWindowInsets(WindowInsets insets) {
int childCount = getChildCount();
for (int index = 0; index < childCount; index++) {
View view = getChildAt(index);
if (view instanceof BottomNavigationView) {
int bottom = insets.getSystemWindowInsetBottom();
if (bottom >= ViewUtils.dpToPx(200)) {
// keyboard is shown
view.setVisibility(GONE);
} else {
// keyboard is hidden
view.setVisibility(VISIBLE);
}
}
}
return insets;
}
}
这个想法是,当键盘显示时,系统insets被改变为相当大的.bottom值。
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。
这里有一个工作区,以了解软键盘是否可见。
检查系统上正在运行的服务 ActivityManager.getRunningServices (max_count_of_services); 从返回的ActivityManager。运行ningserviceinfo实例,检查软键盘服务的clientCount值。 前面提到的clientCount将在每次显示软键盘时递增。例如,如果clientCount为 一开始是1,显示键盘时是2。 在键盘撤销时,clientCount递减。在本例中,它重置为1。
一些流行的键盘在它们的classname中有特定的关键字:
Google AOSP = IME
Swype = IME
Swiftkey = KeyboardService
Fleksy = keyboard
Adaptxt = IME (KPTAdaptxtIME)
Smart = Keyboard (SmartKeyboard)
从ActivityManager。RunningServiceInfo,在ClassNames中检查上述模式。同时,ActivityManager。RunningServiceInfo的clientPackage=android,表示键盘绑定到系统。
可以将上述信息进行严格的组合,以判断软键盘是否可见。
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