<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();
}
}
}
}

代码的使用：

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。