全屏显示的包含webview的页面中弹出的软键盘覆盖输入框的问题

备注 1.使用adjustResize属性时，若是界面中没有滚动条，须要添加一个滚动条scrollview包裹全部内容，保证resize后 能滚动显示显示不下的内容 2.全屏fullscreen模式时 adjustResize属性失效，属因而一个bug，只能使用adjustPan 来设置焦点 3.全屏fullscreen模式时 webview adjustPan 偶尔也会失效

首先，在全屏的状态下，android:windowSoftInputMode="adjustResize"属性是不起做用的，官方文档中有记录： Window flag: hide all screen decorations (such as the status bar) while this window is displayed. This allows the window to use the entire display space for itself -- the status bar will be hidden when an app window with this flag set is on the top layer. A fullscreen window will ignore a value of SOFT_INPUT_ADJUST_RESIZE for the window's softInputMode field; the window will stay fullscreen and will not resize. 大意就是说在全屏状态下，会忽略SOFT_INPUT_ADJUST_RESIZE属性。而全屏状态下设置为android:windowSoftInputMode="adjustPan"也不必定会起做用。

http://stackoverflow.com/questions/7417123/android-how-to-adjust-layout-in-full-screen-mode-when-softkeyboard-is-visible/19494006#19494006在此找到了解决方法。

<!-- lang: java -->
      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) {
            FrameLayout content = (FrameLayout) activity.findViewById(android.R.id.content);
            mChildOfContent = content.getChildAt(0);
            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();
                int heightDifference = usableHeightSansKeyboard - usableHeightNow;
                if (heightDifference > (usableHeightSansKeyboard/4)) {
                    // keyboard probably just became visible
                    frameLayoutParams.height = usableHeightSansKeyboard - heightDifference;
                } else {
                    // keyboard probably just became hidden
                    frameLayoutParams.height = usableHeightSansKeyboard;
                }
                mChildOfContent.requestLayout();
                usableHeightPrevious = usableHeightNow;
            }
        }
    
        private int computeUsableHeight() {
            Rect r = new Rect();
            mChildOfContent.getWindowVisibleDisplayFrame(r);
            return (r.bottom - r.top);
        }
    
    }

只要在setContentvView以后调用assistActivity 方法便可。 在具体使用时发现有时键盘弹出后点击空白处隐藏键盘，布局并无恢复全屏，发现是有时候OnGlobalLayoutListener监听并无被触发，后替换成OnPreDrawListener监听便可。 经多个模拟器与真机测试，发现OnGlobalLayoutListener能够正常使用，应该是个别系统问题