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);
}

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
        }
     }
});

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
    }
  }
});

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);
}

哇，安卓极客们有好消息了。是时候向旧的方式说再见了。 首先我将添加官方发布说明来阅读和了解更多关于这些方法/类，然后我们将看到这些神奇的方法/类

注意:在这些类/方法发布之前，不要将它们添加到你的发布应用中

如何检查键盘可见性

val insets = ViewCompat.getRootWindowInsets(view)
val isKeyboardVisible = insets.isVisible(Type.ime())

其他用途很少

如何获取键盘的高度

val insets = ViewCompat.getRootWindowInsets(view)
val keyboardHeight = insets.getInsets(Type.ime()).bottom

如何显示/隐藏键盘

val controller = view.windowInsetsController

// Show the keyboard
controller.show(Type.ime())

// Hide the keyboard
controller.hide(Type.ime())

注意:WindowInsetsController是在API-30中添加的，所以要等到向后兼容类不可用。

如何听键盘隐藏/显示事件

ViewCompat.setOnApplyWindowInsetsListener(view) { v, insets ->
    val isKeyboardVisible = insets.isVisible(Type.ime())
    if (isKeyboardVisible) {
        // Do it when keyboard is being shown
    } else {
        // Do it when keyboard is hidden
    }

    // Return the insets to keep going down this event to the view hierarchy
    insets
}

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