如何检查软件键盘的知名度的Andr​​oid？ [英] How to check visibility of software keyboard in Android?

问题描述

我需要做一个很简单的事情 - 看看软键盘显示。这是可能在Android中？

I need to do a very simple thing - find out if the software keyboard is shown. Is this possible in Android?

推荐答案

新的答案 补充2012年1月25日的

由于写下面的答案，有人避让我的<一个存在href="http://developer.android.com/reference/android/view/ViewTreeObserver.html">ViewTreeObserver和朋友，原料药已经潜伏在SDK版本以来1。

Since writing the below answer, someone clued me in to the existence of ViewTreeObserver and friends, APIs which have been lurking in the SDK since version 1.

，而不需要自定义布局类型，一个更简单的解决办法就是给你活动的根查看已知的ID，说'@ + ID / activityRoot，勾GlobalLayoutListener到ViewTreeObserver，并从那里计算之间的大小差异您的活动的视图根和窗口大小：

Rather than requiring a custom Layout type, a much simpler solution is to give your activity's root view a known ID, say '@+id/activityRoot', hook a GlobalLayoutListener into the ViewTreeObserver, and from there calculate the size diff between your activity's view root and the window size:

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 > 100) { // if more than 100 pixels, its probably a keyboard...
            ... do something here
        }
     }
});

轻松！

注意： 您的应用程序必须设置该标志在Android清单机器人：windowSoftInputMode =adjustResize，否则上述解决方案将无法正常工作

Note: Your application must set this flag in Android Manifest android:windowSoftInputMode="adjustResize" otherwise above solution will not work.

原来的答案

是的，它是可能的，但它远远难度比它应该是。

Yes it's possible, but it's far harder than it ought to be.

如果我需要关心的时候，键盘的出现和消失（这是相当频繁），那么我要做的就是定制我的顶层布局类为一个将覆盖 onMeasure（）。基本逻辑是如果布局发现自己填充显著小于窗口的总面积，则软键盘被大​​概示出。

If I need to care about when the keyboard appears and disappears (which is quite often) then what I do is customize my top-level layout class into one which overrides onMeasure(). The basic logic is that if the layout finds itself filling significantly less than the total area of the window, then a soft keyboard is probably showing.

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);       
    }

    }

然后在你的Activity类...

Then in your Activity class...

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
    }

    ...
}

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