Android的WebView加载的Html输入框被手机键盘挡住解决

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_demo);
//关键下面一句
AndroidBug5497Workaround.assistActivity(this);
}

import android.app.Activity;
import android.graphics.Rect;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.FrameLayout;

/**
* Created by lizhengxuan on 2017/10/14.
*/

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);
}

}