Android全屏时软键盘监听

作者：ADark0915

出处：http://www.cnblogs.com/shelly-li/

首先，在manifest文件中声明此Activity的windowSoftInputMode属性，

  android:windowSoftInputMode="stateVisible|adjustResize" 

在Activity中 声明所需用到的变量以及布局的事件监听，

private boolean mBackEnable = false;
private boolean mIsBtnBack = false;
private int rootBottom = Integer.MIN_VALUE;
private OnGlobalLayoutListener mOnGlobalLayoutListener = new OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        Rect r = new Rect();
        mSearchLayout.getGlobalVisibleRect(r);
        // 进入Activity时会布局，第一次调用onGlobalLayout，先记录开始软键盘没有弹出时底部的位置
        if (rootBottom == Integer.MIN_VALUE) {
            rootBottom = r.bottom;
            return;
        }
        // adjustResize，软键盘弹出后高度会变小
        if (r.bottom < rootBottom) {
            mBackEnable = false;
        } else {
            mBackEnable = true;
            if (mIsBtnBack) {
                finish();
            }
        }
    }
};

然后在onCreat方法中去注册事件监听

mSearchLayout.getViewTreeObserver().addOnGlobalLayoutListener(mOnGlobalLayoutListener);

注意：这个mSearchlayout是你整个Activity的布局引用

最后，别忘了，在onDestroy方法中回收掉事件的监听

  @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
 @Override
  protected void onDestroy() {
    if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) {
        
   mSearchLayout.getViewTreeObserver().removeGlobalOnLayoutListener(mOnGlobalLayoutListener);
    } else {
        
   mSearchLayout.getViewTreeObserver().removeOnGlobalLayoutListener(mOnGlobalLayoutListener);
    }
    super.onDestroy();
}

到这里，android软键盘的监听就结束了。

什么？你说全屏的时候，没有效果？？？

好吧，我也遇到了。。。

我在项目中实现了所有界面的沉浸式效果，本以为Activity设置了adjustResize，OnGlobalLayoutListener仍然能监听软键盘的变化，结果却是屡试不行。。。

无奈，只能求助。查了一些资料，发现这原来是android的一个bug。下面是具体的bug修复代码片段

public class AndroidAdjustResizeBugFix {
private View mChildOfContent;
private int usableHeightPrevious;
private int statusBarHeight;
private FrameLayout.LayoutParams frameLayoutParams;
private Activity mActivity;

private AndroidAdjustResizeBugFix(Activity activity) {
    mActivity = activity;
    FrameLayout content = (FrameLayout) activity.findViewById(android.R.id.content);
    mChildOfContent = content.getChildAt(0);
    statusBarHeight = getStatusBarHeight();
    mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        public void onGlobalLayout() {
            possiblyResizeChildOfContent();
        }
    });
    frameLayoutParams = (FrameLayout.LayoutParams) mChildOfContent.getLayoutParams();
}
public static void assistActivity(Activity activity) {
    new AndroidAdjustResizeBugFix(activity);
}
private void possiblyResizeChildOfContent() {
    int usableHeightNow = computeUsableHeight();
    if (usableHeightNow != usableHeightPrevious) {
        int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
        int heightDifference = usableHeightSansKeyboard - usableHeightNow;
        if (heightDifference > (usableHeightSansKeyboard / 4)) {
            // keyboard probably just became visible
            // 如果有高度变化，mChildOfContent.requestLayout()之后界面才会重新测量
            // 这里就随便让原来的高度减去了1
            frameLayoutParams.height = usableHeightSansKeyboard - 1;
          键盘开启
        } else {
            // keyboard probably just became hidden
            frameLayoutParams.height = usableHeightSansKeyboard; 
        键盘关闭
        }
        mChildOfContent.requestLayout();
        usableHeightPrevious = usableHeightNow;
    }
}
private int computeUsableHeight() {
    Rect r = new Rect();
    mChildOfContent.getWindowVisibleDisplayFrame(r);
    return r.bottom - r.top + statusBarHeight;
}
private int getStatusBarHeight() {
    try {
        Class c = Class.forName("com.android.internal.R$dimen");
        Object obj = c.newInstance();
        Field field = c.getField("status_bar_height");
        int x = Integer.parseInt(field.get(obj).toString());
        int dimensionPixelSize = mActivity.getResources().getDimensionPixelSize(x);
        return dimensionPixelSize;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return 0;
}

}
把这个类作为一个工具类，添加到项目中，然后，在需要做优化的Activity的onCreate方法中注册activity即可，如：

AndroidAdjustResizeBugFix.assistActivity(this);

以上，就是关于监听软键盘弹出和收起的所有内容。