Android监听软键盘弹出与隐藏
监听布局的GlobalLayoutListener来实现对软键盘弹出与隐藏的监听，先上代码：
public class SoftKeyBoardUtil implements ViewTreeObserver.OnGlobalLayoutListener {
private final ActivitymAct;
private SoftKeyBoardListener mListener;
private View mChildOfContent;
private int usableHeightPrevious;
public SoftKeyBoardUtil(Activity act){
this.mAct=act;
}
/**
* 软件盘监听
*@paramlistener
*/
public void setListener(SoftKeyBoardListener listener){
this.mListener=listener;
}
/**
* 监听GlobalLayoutListener
*/
public void addGlobalLayoutListener(){
mChildOfContent=((ViewGroup)mAct.findViewById(android.R.id.content)).getChildAt(0);
mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(this);
}
/**
* 移除GlobalLayoutListener
*/
public void removeGlobalLayoutListener(){
mChildOfContent.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
/**
* 软键盘展示与隐藏逻辑判断
*/
@Override
public void onGlobalLayout() {
int usableHeightNow = computeUsableHeight();
if(usableHeightNow !=usableHeightPrevious) {
usableHeightPrevious=usableHeightNow;
int usableHeightSansKeyboard =mChildOfContent.getRootView().getHeight();
int heightDifference = usableHeightSansKeyboard - usableHeightNow;
//判断软键盘是否显示逻辑，可以根据具体情况修改
boolean isKeyBoardShow=heightDifference > (usableHeightSansKeyboard/4);
if(mListener!=null){
mListener.OnSoftKeyboardStateChangedListener(isKeyBoardShow,usableHeightNow);
}
}
}
private int computeUsableHeight() {
Rect rect =new Rect();
mChildOfContent.getWindowVisibleDisplayFrame(rect);
// rect.top其实是状态栏的高度，如果是全屏主题，直接 return rect.bottom就可以了
return(rect.bottom- rect.top);
}
/**
* 软键盘监听接口
*/
public static interface SoftKeyBoardListener{
void OnSoftKeyboardStateChangedListener(booleanisKeyBoardShow, intkeyboardHeight);
}
通过mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(this)监听mChildOfContent的布局变化，核心代码是onGlobalLayout()、computeUsableHeight()方法，computeUsableHeight()通过view的getWindowVisibleDisplayFrame(rect)获取view的可见视图区，通常软键盘的弹出隐藏，mChildOfContent的可视区会变化，通过这个computeUsableHeight()获取可视区得高度，然后在onGlobalLayout()方法里处理软键盘是否显示逻辑；boolean isKeyBoardShow=heightDifference > (usableHeightSansKeyboard/4)这个判断逻辑可以根据情况自己修改。
