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
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
其他回答
在了解了不同分辨率的一些问题后,我决定使用相对大小。正如我所注意到的,可见状态和隐藏状态之间的差异约为30%。所以我决定用0.3代替128 PX。
我添加了这个类监听器来通知任何变化。
这是我的版本
import android.app.*;
import android.graphics.*;
import android.view.*;
public class SoftKeyboardState {
public static final int HIDDEN = 0, VISIBLE = 1;
private OnKeyboardStateChangedListener listener;
private View decorView;
public SoftKeyboardState(Activity activity) {
this.decorView = activity.findViewById(android.R.id.content);
initKeyboardListener();
}
private void initKeyboardListener() {
decorView.getViewTreeObserver().addOnGlobalLayoutListener(
new ViewTreeObserver.OnGlobalLayoutListener(){
private final Rect windowVisibleDisplayFrame = new Rect();
private int lastVisibleDecorViewHeight;
@Override
public void onGlobalLayout() {
decorView.getWindowVisibleDisplayFrame(windowVisibleDisplayFrame);
final int visibleDecorViewHeight = windowVisibleDisplayFrame.height();
if (lastVisibleDecorViewHeight != 0) {
if ((lastVisibleDecorViewHeight > visibleDecorViewHeight) && (lastVisibleDecorViewHeight / visibleDecorViewHeight >= 0.3f)) {
// visible
if (listener != null)listener.onKeyboardStateChanged(VISIBLE);
} else if ((lastVisibleDecorViewHeight < visibleDecorViewHeight) && (visibleDecorViewHeight / lastVisibleDecorViewHeight >= 0.3f)) {
// hidden
if (listener != null)listener.onKeyboardStateChanged(HIDDEN);
}
}
lastVisibleDecorViewHeight = visibleDecorViewHeight;
}
});
}
public void setOnKeyboardStateChangedListener(OnKeyboardStateChangedListener listener) {
this.listener = listener;
}
public interface OnKeyboardStateChangedListener {
public void onKeyboardStateChanged(int state);
}
}
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。
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 ... \\
}
}
});
一些改进,以避免在高密度设备上错误地检测软键盘的可见性:
Threshold of height difference should be defined as 128 dp, not 128 pixels. Refer to Google design doc about Metrics and Grid, 48 dp is comfortable size for touch object and 32 dp is minimum for buttons. Generic soft keyboard should include 4 rows of key buttons, so minimum keyboard height should be: 32 dp * 4 = 128 dp, that means threshold size should transfer to pixels by multiply device density. For xxxhdpi devices (density 4), the soft keyboard height threshold should be 128 * 4 = 512 pixels. Height difference between root view and its visible area: root view height - status bar height - visible frame height = root view bottom - visible frame bottom, since status bar height equal to the top of root view visible frame. private final String TAG = "TextEditor"; private TextView mTextEditor; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_editor); mTextEditor = (TextView) findViewById(R.id.text_editor); mTextEditor.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() { @Override public void onGlobalLayout() { isKeyboardShown(mTextEditor.getRootView()); } }); } private boolean isKeyboardShown(View rootView) { /* 128dp = 32dp * 4, minimum button height 32dp and generic 4 rows soft keyboard */ final int SOFT_KEYBOARD_HEIGHT_DP_THRESHOLD = 128; Rect r = new Rect(); rootView.getWindowVisibleDisplayFrame(r); DisplayMetrics dm = rootView.getResources().getDisplayMetrics(); /* heightDiff = rootView height - status bar height (r.top) - visible frame height (r.bottom - r.top) */ int heightDiff = rootView.getBottom() - r.bottom; /* Threshold size: dp to pixels, multiply with display density */ boolean isKeyboardShown = heightDiff > SOFT_KEYBOARD_HEIGHT_DP_THRESHOLD * dm.density; Log.d(TAG, "isKeyboardShown ? " + isKeyboardShown + ", heightDiff:" + heightDiff + ", density:" + dm.density + "root view height:" + rootView.getHeight() + ", rect:" + r); return isKeyboardShown; }
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
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