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

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)。

其他回答

这个解决方案可能会重新打开键盘,但它是有效的。

InputMethodManager inputManager = ( (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE) );

private boolean isKeyboardShowing() {

    boolean isKeyboardShowing = inputManager.hideSoftInputFromWindow(irrelevantView.getWindowToken(), 0);
    if (isKeyboardShowing) {
        inputManager.showSoftInput(this.getCurrentFocus(), 0);
    }
    return isKeyboardShowing;
}

抱歉回答晚了,但我已经创建了一个小的帮助类来处理打开/关闭事件,通知侦听器和其他有用的东西,可能有人会发现它有帮助:

import android.graphics.Rect;
import android.view.View;
import android.view.ViewTreeObserver;

import java.util.LinkedList;
import java.util.List;

public class SoftKeyboardStateWatcher implements ViewTreeObserver.OnGlobalLayoutListener {

    public interface SoftKeyboardStateListener {
        void onSoftKeyboardOpened(int keyboardHeightInPx);
        void onSoftKeyboardClosed();
    }

    private final List<SoftKeyboardStateListener> listeners = new LinkedList<SoftKeyboardStateListener>();
    private final View activityRootView;
    private int        lastSoftKeyboardHeightInPx;
    private boolean    isSoftKeyboardOpened;

    public SoftKeyboardStateWatcher(View activityRootView) {
        this(activityRootView, false);
    }

    public SoftKeyboardStateWatcher(View activityRootView, boolean isSoftKeyboardOpened) {
        this.activityRootView     = activityRootView;
        this.isSoftKeyboardOpened = isSoftKeyboardOpened;
        activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    @Override
    public void onGlobalLayout() {
        final Rect r = new Rect();
        //r will be populated with the coordinates of your view that area still visible.
        activityRootView.getWindowVisibleDisplayFrame(r);

        final int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
        if (!isSoftKeyboardOpened && heightDiff > 100) { // if more than 100 pixels, its probably a keyboard...
            isSoftKeyboardOpened = true;
            notifyOnSoftKeyboardOpened(heightDiff);
        } else if (isSoftKeyboardOpened && heightDiff < 100) {
            isSoftKeyboardOpened = false;
            notifyOnSoftKeyboardClosed();
        }
    }

    public void setIsSoftKeyboardOpened(boolean isSoftKeyboardOpened) {
        this.isSoftKeyboardOpened = isSoftKeyboardOpened;
    }

    public boolean isSoftKeyboardOpened() {
        return isSoftKeyboardOpened;
    }

    /**
     * Default value is zero {@code 0}.
     *
     * @return last saved keyboard height in px
     */
    public int getLastSoftKeyboardHeightInPx() {
        return lastSoftKeyboardHeightInPx;
    }

    public void addSoftKeyboardStateListener(SoftKeyboardStateListener listener) {
        listeners.add(listener);
    }

    public void removeSoftKeyboardStateListener(SoftKeyboardStateListener listener) {
        listeners.remove(listener);
    }

    private void notifyOnSoftKeyboardOpened(int keyboardHeightInPx) {
        this.lastSoftKeyboardHeightInPx = keyboardHeightInPx;

        for (SoftKeyboardStateListener listener : listeners) {
            if (listener != null) {
                listener.onSoftKeyboardOpened(keyboardHeightInPx);
            }
        }
    }

    private void notifyOnSoftKeyboardClosed() {
        for (SoftKeyboardStateListener listener : listeners) {
            if (listener != null) {
                listener.onSoftKeyboardClosed();
            }
        }
    }
}

使用的例子:

final SoftKeyboardStateWatcher softKeyboardStateWatcher 
    = new SoftKeyboardStateWatcher(findViewById(R.id.activity_main_layout);

// Add listener
softKeyboardStateWatcher.addSoftKeyboardStateListener(...);
// then just handle callbacks

我花了一点时间才想明白……我运行它一些castexception,但发现你可以用类的名称替换layout.xml中的LinearLayout。

是这样的:

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/llMaster">

<com.ourshoppingnote.RelativeLayoutThatDetectsSoftKeyboard android:background="@drawable/metal_background"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:id="@+id/rlMaster" >
    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="1dip" android:background="@drawable/line"></LinearLayout>

          ....

</com.ourshoppingnote.RelativeLayoutThatDetectsSoftKeyboard>    


</LinearLayout>

这样你就不会遇到任何演员问题。

... 如果你不想在每个页面上都这样做,我建议你使用“安卓版MasterPage”。点击这里查看链接: http://jnastase.alner.net/archive/2011/01/08/ldquomaster-pagesrdquo-in-android.aspx

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 ... \\
        }
    }
});

视图#setOnApplyWindowInsetsListener可以用来获得窗口insets回调

public void setOnApplyWindowInsetsListener(OnApplyWindowInsetsListener listener) {
    getListenerInfo().mOnApplyWindowInsetsListener = listener;
}

//OnApplyWindowInsetsListener
public WindowInsets onApplyWindowInsets(View v, WindowInsets insets);

boolean keyboardVisible = insets.isVisible(WindowInsets.Type.ime())可以给出可见性状态。