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; }
其他回答
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。
当在viewpager中改变片段的方向时,我很难保持键盘状态。我不知道为什么,但它似乎是不稳定的,行为不同于标准的活动。
在这种情况下,要保持键盘状态,首先你应该添加android:windowSoftInputMode = "stateUnchanged"到你的AndroidManifest.xml。不过,您可能会注意到,这实际上并没有解决整个问题——如果在方向改变之前打开了键盘,那么键盘就不会为我打开。在其他所有情况下,这种行为似乎都是正确的。
然后,我们需要实现这里提到的解决方案之一。 我发现的最干净的一个是George Maisuradze的——使用hideSoftInputFromWindow中的布尔回调:
InputMethodManager imm = (InputMethodManager) getSystemService(Activity.INPUT_METHOD_SERVICE);
return imm.hideSoftInputFromWindow(mViewPager.getWindowToken(), 0);
我将这个值存储在我的Fragment的onSaveInstanceState方法中,并在onCreate中检索它。然后,我强制显示键盘在onCreateView,如果它有一个值为真(它返回真,如果键盘是可见的,实际上隐藏它之前的片段销毁)。
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
}
}
});
Reuben Scratton的新答案(计算HeightDiff int HeightDiff = activityRootView.getRootView().getHeight() - activityRootView.getHeight();)如果您设置半透明状态栏模式,将无法在活动中工作。
如果你使用半透明状态栏,activityRootView.getHeight()将永远不会改变软键盘是否可见。它将始终返回活动和状态栏的高度。
例如,Nexus 4, Android 5.0.1,将Android:windowTranslucentStatus设置为true,它将永远返回1184,即使ime已经打开。如果你设置android:windowTranslucentStatus为false,它将正确返回高度,如果ime不可见,它将返回1134(不包括状态栏)。关闭ime,它可能会返回5xx(取决于ime的高度)
我不知道这是否是一个bug,我已经尝试了4.4.4和5.0.1,结果是一样的。
所以,到目前为止,第二个最被认可的答案,Kachi的解决方案将是最安全的方法来计算ime的高度。以下是一份复印件:
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.bottom - r.top);
if (heightDiff > 100) { // if more than 100 pixels, its probably a keyboard...
... do something here
}
}
});
这些解决方案都不适用于棒棒糖。在Lollipop activityRootView.getRootView(). getheight()包含按钮栏的高度,而测量视图则不包含。我已经采用了上面最好/最简单的解决方案来处理棒棒糖。
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.bottom - r.top);
Resources res = getResources();
// The status bar is 25dp, use 50dp for assurance
float maxDiff =
TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 50, res.getDisplayMetrics());
//Lollipop includes button bar in the root. Add height of button bar (48dp) to maxDiff
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
float buttonBarHeight =
TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 48, res.getDisplayMetrics());
maxDiff += buttonBarHeight;
}
if (heightDiff > maxDiff) { // if more than 100 pixels, its probably a keyboard...
...do something here
}
}
});
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