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

除了正确的答案，我必须在onCreateView的末尾添加这个，当使用一个片段内的webview。

getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);

可能是因为我在一个片段中运行Webview，或者可能是API 30上的一个新行为，我的问题是，即使显示键盘，片段的高度也从未改变。

所以对于Fragment，整个代码应该是

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = super.onCreateView(inflater, container, savedInstanceState);
    //mWebView.postUrl("https://www.google.com/");
    final View activityRootView = view;
    layoutListener = 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);
            // This variable was created only for Debug purposes and 
            // to see the height change when clicking on a field inside mWebView
            int screenHeight = activityRootView.getRootView().getHeight();
            Log.d("onGlobalLayout", "rect: " + r.toString());
            Log.d("onGlobalLayout", "screenHeight: " + screenHeight);

            //The difference on the heights from bottom to top and on the root height
            int heightDiff = screenHeight - (r.bottom - r.top);
            Log.d("onGlobalLayout", "heightDiff: " + heightDiff);

            //I suggest to put 250 on resources to have better order
            float dpx = dpToPx(getActivity(), 250);

            if (previousHeightDiff != heightDiff) {
                if (heightDiff > dpx) {
                    isSoftKeyboardPresent = true;
                } else {
                    isSoftKeyboardPresent = false;
                }
                previousHeightDiff = heightDiff;
            }
        }
    };
    activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(layoutListener);
    getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);
    return view;
}

private static float dpToPx(Context context, float valueInDp) {
    DisplayMetrics metrics = context.getResources().getDisplayMetrics();
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, valueInDp, metrics);
}

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
    }
 }
}); 

我知道这是一篇老文章，但我认为这是我所知道的最简单的方法，我的测试设备是Nexus 5。我还没有在其他设备上尝试过。希望其他人会分享他们的方法，如果他们发现我的代码不好:)

public static boolean isKeyboardShown(Context context, View view) {
        if (context == null || view == null) {
            return false;
        }
        InputMethodManager imm = (InputMethodManager) context
                .getSystemService(Context.INPUT_METHOD_SERVICE);
        return imm.hideSoftInputFromWindow(view.getWindowToken(), 0); 
}

imm。hideSoftInputFromWindow返回布尔值。

谢谢,

你可以通过使用活动的decorView来观察软键盘的隐藏。

public final class SoftKeyboardUtil {
    public static final String TAG = "SoftKeyboardUtil";
    public static void observeSoftKeyBoard(Activity activity , final OnSoftKeyBoardHideListener listener){
        final View decorView = activity.getWindow().getDecorView();
        decorView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                Rect rect = new Rect();
                decorView.getWindowVisibleDisplayFrame(rect);
                int displayHight = rect.bottom - rect.top;
                int hight = decorView.getHeight();
                boolean hide = (double)displayHight / hight > 0.8 ;
                if(Log.isLoggable(TAG, Log.DEBUG)){
                    Log.d(TAG ,"DecorView display hight = "+displayHight);
                    Log.d(TAG ,"DecorView hight = "+ hight);
                    Log.d(TAG, "softkeyboard visible = " + !hide);
                }

                listener.onSoftKeyBoardVisible(!hide);

            }
        });
    }



    public interface OnSoftKeyBoardHideListener{
        void onSoftKeyBoardVisible(boolean visible);
    }
}

我使用了与鲁班的答案略有不同的答案，事实证明在某些情况下更有帮助，特别是在使用高分辨率设备时。

final View activityRootView = findViewById(android.R.id.content);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(
        new OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                int heightView = activityRootView.getHeight();
                int widthView = activityRootView.getWidth();
                if (1.0 * widthView / heightView > 3) {
                    //Make changes for Keyboard not visible
                } else {
                    //Make changes for keyboard visible
                }
            }
        });