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
不要编写任何硬代码。最好的方法是,你必须调整你的视图,而Get Focus on EditText与键盘显示。 您可以使用下面的代码将活动上的resize属性添加到清单文件中。
android: windowSoftInputMode = adjustResize”
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
}
}
});
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; }
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
这可能不适合生产环境,因为它会打开键盘。注意,类似函数返回的布尔值在API中没有指定,因此是不可靠的。参考这里的文档…
https://developer.android.com/reference/android/view/inputmethod/InputMethodManager showSoftInput (% 20 int, android.view.View % 20 android.os.resultreceiver)
public boolean showSoftInput (View view,
int flags,
ResultReceiver resultReceiver)
注意,这个方法接受一个ResultReceiver。它可以得到结果:result_unchanged_shows, RESULT_UNCHANGED_HIDDEN, result_shows,或RESULT_HIDDEN。如果得到result_unchanged_show,则键盘是可见的。如果你需要它保持关闭如果它已经关闭了,你需要关闭它。
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);
}
}
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