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
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
其他回答
我发现@Reuben_Scratton的方法与@Yogesh的方法的组合似乎效果最好。将他们的方法结合起来会产生如下结果:
final View activityRootView = findViewById(R.id.activityRoot);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
if (getResources().getConfiguration().keyboardHidden == Configuration.KEYBOARDHIDDEN_NO) { // Check if keyboard is not hidden
// ... 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; }
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。
这个想法是,如果你需要隐藏你的键盘,同时检查软输入状态,使用以下解决方案:
public boolean hideSoftInput() {
InputMethodManager imm = (InputMethodManager) getSystemService(Activity.INPUT_METHOD_SERVICE);
return imm.hideSoftInputFromWindow(mViewPager.getWindowToken(), 0);
}
如果在隐藏之前显示键盘,则此方法返回true。
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。
推荐文章
- 警告:API ' variable . getjavacompile()'已过时,已被' variable . getjavacompileprovider()'取代
- 安装APK时出现错误
- 碎片中的onCreateOptionsMenu
- TextView粗体通过XML文件?
- 如何使线性布局的孩子之间的空间?
- DSL元素android.dataBinding。enabled'已过时,已被'android.buildFeatures.dataBinding'取代
- ConstraintLayout:以编程方式更改约束
- PANIC: AVD系统路径损坏。检查ANDROID_SDK_ROOT值
- 如何生成字符串类型的buildConfigField
- Recyclerview不调用onCreateViewHolder
- Android API 21工具栏填充
- Android L中不支持操作栏导航模式
- 如何在TextView中添加一个子弹符号?
- PreferenceManager getDefaultSharedPreferences在Android Q中已弃用
- 在Android Studio中创建aar文件