非常容易

1. 把id放在根视图上

rootView只是一个视图指向我的根视图在这种情况下，一个相对布局:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:id="@+id/addresses_confirm_root_view"
                android:background="@color/WHITE_CLR">

2. 在Activity中初始化根视图:

RelativeLayout rootView = (RelativeLayout) findViewById(R.id.addresses_confirm_root_view);

3.使用getViewTreeObserver()检测键盘是否打开或关闭

    rootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                int heightDiff = rootView.getRootView().getHeight() - rootView.getHeight();
                
                if (heightDiff > 100) { // Value should be less than keyboard's height 
                    Log.e("MyActivity", "keyboard opened");
                } else { 
                    Log.e("MyActivity", "keyboard closed");
                }
            }
        });

这对我很有用。也许这对于所有版本来说都是最好的方法。

这将是有效的，使键盘可见性的属性，并观察这个变化延迟，因为onGlobalLayout方法调用多次。此外，检查设备旋转和windowSoftInputMode是否为adjustNothing也很好。

boolean isKeyboardShowing = false;
void onKeyboardVisibilityChanged(boolean opened) {
    print("keyboard " + opened);
}

// ContentView is the root view of the layout of this activity/fragment    
contentView.getViewTreeObserver().addOnGlobalLayoutListener(
    new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {

        Rect r = new Rect();
        contentView.getWindowVisibleDisplayFrame(r);
        int screenHeight = contentView.getRootView().getHeight();

        // r.bottom is the position above soft keypad or device button.
        // if keypad is shown, the r.bottom is smaller than that before.
        int keypadHeight = screenHeight - r.bottom;

        Log.d(TAG, "keypadHeight = " + keypadHeight);

        if (keypadHeight > screenHeight * 0.15) { // 0.15 ratio is perhaps enough to determine keypad height.
            // keyboard is opened
            if (!isKeyboardShowing) {
                isKeyboardShowing = true
                onKeyboardVisibilityChanged(true)
            }
        }
        else {
            // keyboard is closed
            if (isKeyboardShowing) {
                isKeyboardShowing = false
                onKeyboardVisibilityChanged(false)
            }
        }
    }
});

final View activityRootView = findViewById(R.id.rootlayout);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {

            Rect r = new Rect();
            activityRootView.getWindowVisibleDisplayFrame(r);

            int screenHeight = activityRootView.getRootView().getHeight();
            Log.e("screenHeight", String.valueOf(screenHeight));
            int heightDiff = screenHeight - (r.bottom - r.top);
            Log.e("heightDiff", String.valueOf(heightDiff));
            boolean visible = heightDiff > screenHeight / 3;
            Log.e("visible", String.valueOf(visible));
            if (visible) {
                Toast.makeText(LabRegister.this, "I am here 1", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(LabRegister.this, "I am here 2", Toast.LENGTH_SHORT).show();
            }
        }
});

如你所知，android软件的键盘只有在有可能的输入事件时才可见。换句话说，只有当EditText被聚焦时，键盘才可见。这意味着你可以通过使用OnFocusChangeListener获得键盘是否可见。

//Declare this Globally

public boolean isKeyBoardVisible = false;

//In OnCreate *[For Activity]*, OnCreateView *[For Fragment]*

text_send.setOnFocusChangeListener(new View.OnFocusChangeListener() {

    @Override
    public void onFocusChange(View v, boolean hasFocus) {
        if(hasFocus)
            isKeyBoardVisible = true;
        else
            isKeyBoardVisible = false;
    }
});

现在你可以在类的任何地方使用isKeyBoardVisible变量来获取键盘是否打开。这对我来说很有效。

注意:当使用InputMethodManager以编程方式打开键盘时，这个过程不起作用，因为它不调用OnFocusChangeListener。

在我的情况下，我只有一个编辑文本来管理我的布局，所以我想出了这个解决方案。 它工作得很好，基本上它是一个自定义的EditText，它监听焦点，并在焦点改变或按下后退/完成按钮时发送本地广播。 要工作，你需要在你的布局与android: focableintouchmode ="true"和android:focusableInTouchMode="true"，因为当你调用clearFocus()的焦点将被重新分配到第一个可聚焦的视图。 虚拟视图示例:

<View
android:layout_width="1dp"
android:layout_height="1dp"
android:focusable="true"
android:focusableInTouchMode="true"/>

额外的信息

检测布局变化差异的解决方案效果不太好，因为它强烈依赖于屏幕密度，因为100px在某些设备上可能很大，而在其他设备上可能没有，你可能会得到误报。 另外，不同的厂商有不同的键盘。

在Android中，你可以通过ADB shell进行检测。我写下并使用了这个方法:

{
        JSch jsch = new JSch();
        try {
            Session session = jsch.getSession("<userName>", "<IP>", 22);
            session.setPassword("<Password>");
            Properties config = new Properties();
            config.put("StrictHostKeyChecking", "no");
            session.setConfig(config);
            session.connect();

            ChannelExec channel = (ChannelExec)session.openChannel("exec");
            BufferedReader in = new BufferedReader(new    
            InputStreamReader(channel.getInputStream()));
            channel.setCommand("C:/Android/android-sdk/platform-tools/adb shell dumpsys window 
            InputMethod | findstr \"mHasSurface\"");
            channel.connect();

            String msg = null;
            String msg2 = " mHasSurface=true";

            while ((msg = in.readLine()) != null) {
                Boolean isContain = msg.contains(msg2);
                log.info(isContain);
                if (isContain){
                    log.info("Hiding keyboard...");
                    driver.hideKeyboard();
                }
                else {
                    log.info("No need to hide keyboard.");
                }
            }

            channel.disconnect();
            session.disconnect();

        } catch (JSchException | IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}