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);
    }
}

2012年1月25日新增答案

写了下面的答案后，有人告诉我ViewTreeObserver和其他api的存在，这些api从版本1开始就潜伏在SDK中。

而不是需要一个自定义的布局类型，一个更简单的解决方案是给你的活动的根视图一个已知的ID，比如@+ ID /activityRoot，钩子一个GlobalLayoutListener到ViewTreeObserver，并从那里计算你的活动的视图根和窗口大小之间的大小差:

final View activityRootView = findViewById(R.id.activityRoot);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        int heightDiff = activityRootView.getRootView().getHeight() - activityRootView.getHeight();
        if (heightDiff > dpToPx(this, 200)) { // if more than 200 dp, it's probably a keyboard...
            // ... do something here
        }
     }
});

使用一个实用程序，如:

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

简单!

注意: 你的应用程序必须在Android Manifest中设置这个标志Android:windowSoftInputMode=" adjuststresize "否则上述解决方案将无法工作。

原来的答案

是的，这是可能的，但它比应该的要难得多。

如果我需要关心键盘何时出现和消失(这是相当经常的)，那么我所做的是自定义我的顶级布局类为一个覆盖onMeasure()。基本逻辑是，如果布局发现自己填充的面积明显小于窗口的总面积，那么可能显示了软键盘。

import android.app.Activity;
import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.LinearLayout;

/*
 * LinearLayoutThatDetectsSoftKeyboard - a variant of LinearLayout that can detect when 
 * the soft keyboard is shown and hidden (something Android can't tell you, weirdly). 
 */

public class LinearLayoutThatDetectsSoftKeyboard extends LinearLayout {

    public LinearLayoutThatDetectsSoftKeyboard(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public interface Listener {
        public void onSoftKeyboardShown(boolean isShowing);
    }
    private Listener listener;
    public void setListener(Listener listener) {
        this.listener = listener;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int height = MeasureSpec.getSize(heightMeasureSpec);
        Activity activity = (Activity)getContext();
        Rect rect = new Rect();
        activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(rect);
        int statusBarHeight = rect.top;
        int screenHeight = activity.getWindowManager().getDefaultDisplay().getHeight();
        int diff = (screenHeight - statusBarHeight) - height;
        if (listener != null) {
            listener.onSoftKeyboardShown(diff>128); // assume all soft keyboards are at least 128 pixels high
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);       
    }

    }

然后在活动课上…

public class MyActivity extends Activity implements LinearLayoutThatDetectsSoftKeyboard.Listener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ...
        LinearLayoutThatDetectsSoftKeyboard mainLayout = (LinearLayoutThatDetectsSoftKeyboard)findViewById(R.id.main);
        mainLayout.setListener(this);
        ...
    }


    @Override
    public void onSoftKeyboardShown(boolean isShowing) {
        // do whatever you need to do here
    }

    ...
}

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

我认为这个方法将帮助你找出是键盘是可见的或不。

 public Boolean isSoftKeyBoardVisible(){
    InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);

    if (imm.isAcceptingText()) {
        Log.d(TAG,"Software Keyboard was shown");
        return true;
    } else {
        Log.d(TAG,"Software Keyboard was not shown");
        return false;
    }

}

参考@TacB0sS的回答，我在Kotlin中开发了一个类。希望这对你有所帮助。如果需要改进，请告诉我。

class KeyboardVisibilityObserver(val layRootContainer: View?, val keyboardVisibilityListener: KeyboardVisibilityListener?) {
    var isKeyboardOpen = false
        private set

    private var keyBoardObserver = object : ViewTreeObserver.OnGlobalLayoutListener {

        private val DefaultKeyboardDP = 100

        // Lollipop includes button bar in the root. Add height of button bar (48dp) to maxDiff
        private val EstimatedKeyboardDP = DefaultKeyboardDP + if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) 48 else 0

        private val r = Rect()

        override fun onGlobalLayout() {
            if (layRootContainer != null) {
                // Convert the dp to pixels.
                val estimatedKeyboardHeight = TypedValue
                        .applyDimension(TypedValue.COMPLEX_UNIT_DIP, EstimatedKeyboardDP.toFloat(), layRootContainer.resources.displayMetrics).toInt()

                // Conclude whether the keyboard is shown or not.
                layRootContainer.getWindowVisibleDisplayFrame(r)
                val heightDiff = layRootContainer.rootView.height - (r.bottom - r.top)
                val isShown = heightDiff >= estimatedKeyboardHeight

                if (isShown == isKeyboardOpen) {
                    //  Log.d("Keyboard state", "Ignoring global layout change...");
                    return
                }

                isKeyboardOpen = isShown

                keyboardVisibilityListener?.onKeyboardVisibilityChanged(isKeyboardOpen)
            }
        }
    }

    init {
        layRootContainer?.viewTreeObserver?.addOnGlobalLayoutListener(keyBoardObserver)
    }

    // call this in onDestroy
    fun removeObserver(){
        layRootContainer?.viewTreeObserver?.removeOnGlobalLayoutListener(keyBoardObserver)
    }

    interface KeyboardVisibilityListener {
        fun onKeyboardVisibilityChanged(isKeyboardOpen: Boolean)
    }
}

在使用上述大多数建议添加固定数字的解决方案时，我刚刚遇到了一个错误。

S4的dpi很高，导致导航栏的高度为100px，因此我的应用程序认为键盘一直是打开的。

所以，随着所有新的高分辨率手机的发布，我认为使用硬编码值从长远来看不是一个好主意。

在各种屏幕和设备上进行测试后，我发现一个更好的方法是使用百分比。 获取decorView和你的应用内容之间的差异，然后检查这个差异的百分比。 从我得到的统计数据来看，大多数导航栏(无论大小、分辨率等)将占据屏幕的3%到5%。如果键盘是打开的，它会占据屏幕的47%到55%。

作为结论，我的解决方案是检查是否差异超过10%，然后我假设它的键盘打开。