<Android>监听软键盘打开收起事件（软键盘自带收起按钮）

最近在公司开发cocos2dx上的android输入框控件，遇到软键盘的事件监听，通常软键盘的收起方式大致3种：

1.点击软键盘右下角的Return按钮（系统收起）

2.输入框焦点时按返回按钮（系统收起）

3.点击软键盘和输入框的外部（自发收起）

4.点击软键盘自带的收起按钮（软键盘收起）

前三种事件可以监听，方式都比较简单

1.点击软键盘右下角的Return按钮

给输入框设置监听

editText.setOnEditorActionListener(new OnEditorActionListener() {
@Override
public boolean onEditorAction(final TextView v, final int actionId, final KeyEvent event) {
// 可捕捉右下角的Return按钮

//添加抛出收起事件代码
return false;
}
});

2.输入框焦点时按返回按钮

给输入框增加按钮监听

editText.setOnKeyListener(new OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (listener != null) {
// 可添加抛出收起事件代码
}
return true;
}
return false;
}
});

3.点击软键盘和输入框的外部

给输入框的父容器增加触摸监听

@Override
public boolean onTouchEvent(MotionEvent event) {

if (indexOfChild(editText) > -1) {

// 可添加抛出收起事件代码

}

return super.onTouchEvent(event);

}

4.点击软键盘自带的收起按钮（软键盘收起）

问题卡在此处，经过资料的搜查，还是么能找到软键盘收起按钮事件监听的办法，最后在stackoverflow网站找到了从布局高度的变化来判断软键盘的打开和收起事件。

import android.graphics.Rect;
import android.view.View;
import android.view.ViewTreeObserver;

import java.util.LinkedList;
import java.util.List;

public class SoftKeyboardStateHelper implements ViewTreeObserver.OnGlobalLayoutListener {

    public interface SoftKeyboardStateListener {
        void onSoftKeyboardOpened(int keyboardHeightInPx);
        void onSoftKeyboardClosed();
    }

    private final List<SoftKeyboardStateListener> listeners = new LinkedList<SoftKeyboardStateListener>();
    private final View activityRootView;
    private int        lastSoftKeyboardHeightInPx;
    private boolean    isSoftKeyboardOpened;

    public SoftKeyboardStateHelper(View activityRootView) {
        this(activityRootView, false);
    }

    public SoftKeyboardStateHelper(View activityRootView, boolean isSoftKeyboardOpened) {
        this.activityRootView     = activityRootView;
        this.isSoftKeyboardOpened = isSoftKeyboardOpened;
        activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    @Override
    public void onGlobalLayout() {
        final Rect r = new Rect();
        //r will be populated with the coordinates of your view that area still visible.
        activityRootView.getWindowVisibleDisplayFrame(r);

        final int heightDiff = activityRootView.getRootView().getHeight() - (r.bottom - r.top);
        if (!isSoftKeyboardOpened && heightDiff > 100) { // if more than 100 pixels, its probably a keyboard...
            isSoftKeyboardOpened = true;
            notifyOnSoftKeyboardOpened(heightDiff);
        } else if (isSoftKeyboardOpened && heightDiff < 100) {
            isSoftKeyboardOpened = false;
            notifyOnSoftKeyboardClosed();
        }
    }

    public void setIsSoftKeyboardOpened(boolean isSoftKeyboardOpened) {
        this.isSoftKeyboardOpened = isSoftKeyboardOpened;
    }

    public boolean isSoftKeyboardOpened() {
        return isSoftKeyboardOpened;
    }

    /**
     * Default value is zero (0)
     * @return last saved keyboard height in px
     */
    public int getLastSoftKeyboardHeightInPx() {
        return lastSoftKeyboardHeightInPx;
    }

    public void addSoftKeyboardStateListener(SoftKeyboardStateListener listener) {
        listeners.add(listener);
    }

    public void removeSoftKeyboardStateListener(SoftKeyboardStateListener listener) {
        listeners.remove(listener);
    }

    private void notifyOnSoftKeyboardOpened(int keyboardHeightInPx) {
        this.lastSoftKeyboardHeightInPx = keyboardHeightInPx;

        for (SoftKeyboardStateListener listener : listeners) {
            if (listener != null) {
                listener.onSoftKeyboardOpened(keyboardHeightInPx);
            }
        }
    }

    private void notifyOnSoftKeyboardClosed() {
        for (SoftKeyboardStateListener listener : listeners) {
            if (listener != null) {
                listener.onSoftKeyboardClosed();
            }
        }
    }
}

final SoftKeyboardStateHelper softKeyboardStateHelper = new SoftKeyboardStateHelper(findViewById(R.id.activity_main_layout);
softKeyboardStateHelper.addSoftKeyboardStateListener(...);
// then just handle callbacks

地址链接：http://stackoverflow.com/questions/2150078/how-to-check-visibility-of-software-keyboard-in-android

从中选取了这段代码。

这样能一并解决以上4种情况，比较好的监听软键盘的打开和收起事件，目前正在使用中。