android:windowSoftInputMode="adjustSpan"  

public class AndroidBug5497Workaround {

    // For more information, see https://code.google.com/p/android/issues/detail?id=5497
    // To use this class, simply invoke assistActivity() on an Activity that already has its content view set.

    public static void assistActivity(Activity activity) {
        new AndroidBug5497Workaround(activity);
    }

    private View mChildOfContent;
    private int usableHeightPrevious;
    private FrameLayout.LayoutParams frameLayoutParams;

    private AndroidBug5497Workaround(Activity activity) {
        //Decorview里分为title和content，content即是承载我们setContentView方法的布局的根布局
        FrameLayout content = (FrameLayout) activity.findViewById(android.R.id.content);
        //mChildOfContent我们setContentView方法的布局
        mChildOfContent = content.getChildAt(0);
        //监听布局变化，任何界面变化都会触发该监听
        //软键盘弹起同样也会触发该监听
        mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            public void onGlobalLayout() {
                possiblyResizeChildOfContent();
            }
        });
        frameLayoutParams = (FrameLayout.LayoutParams) mChildOfContent.getLayoutParams();
    }

    private void possiblyResizeChildOfContent() {
        int usableHeightNow = computeUsableHeight();
        if (usableHeightNow != usableHeightPrevious) {
            int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
            //计算布局变化的高度
            int heightDifference = usableHeightSansKeyboard - usableHeightNow;
            if (heightDifference > (usableHeightSansKeyboard / 4)) {
                // keyboard probably just became visible
                //如果布局变化的高度大于全屏高度的4分之一，则认为可能是键盘弹出，需要改变我们setContentView的布局高度
                frameLayoutParams.height = usableHeightSansKeyboard - heightDifference;
            } else {
                // keyboard probably just became hidden
                frameLayoutParams.height = usableHeightSansKeyboard;
            }
            //布局改变后重绘
            mChildOfContent.requestLayout();
            usableHeightPrevious = usableHeightNow;
        }
    }

    //计算去掉键盘高度后的可用高度
    private int computeUsableHeight() {
        Rect r = new Rect();
        mChildOfContent.getWindowVisibleDisplayFrame(r);
        return (r.bottom - r.top);// 全屏模式下： return r.bottom
//        return r.bottom;
    }

}

AndroidBug5497Workaround.assistActivity(this);