Android HTML5视频媒体控制器隐藏在对话框后面

我有一个webview来显示html5视频，我的目标是全屏显示视频。为了做到这一点，我必须扩展WebChromeClient类并重写ShowCustomView和OnHideCustomView的方法。我目前正在处理的项目是一个库项目，因此activity_main.xml不可用。然后我使用一个对话框全屏显示视频。问题是mediacontroller未显示。这是我的密码：

@Override
public void onShowCustomView(View view, CustomViewCallback callback) {  
    if (customView != null){
        customViewCallback = callback;
        callback.onCustomViewHidden();
        return;
    }

    root  = new RelativeLayout(mContext);
    customViewCallback = callback;
    customView = view;  

    root.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));
    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    params.addRule(RelativeLayout.CENTER_IN_PARENT, RelativeLayout.TRUE);
    root.addView(customView,params);

    Button closeBtn = new Button(mContext);
    closeBtn.setText("Close");
    params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    params.addRule(RelativeLayout.ALIGN_PARENT_TOP);
    closeBtn.setOnClickListener(new OnClickListener(){
        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            onHideCustomView();
        }           
    });
    root.addView(closeBtn);




    mDialog = new Dialog(mContext,android.R.style.Theme_NoTitleBar_Fullscreen);
    mDialog.setContentView(root);
    mDialog.show();

}

@Override
public void onHideCustomView() {
    if (mDialog != null) {  
        mDialog.dismiss();
        customViewCallback.onCustomViewHidden();
    }

    mDialog = null;
    customView = null;
    root = null;
}

---

customView是一个视图，root是一个RelativeLayout，它们是扩展WebChromeClient类的成员。如何显示媒体控制器，有人帮忙吗？顺便问一下，在这种情况下，有没有办法自定义媒体控制器？

您解决了这个问题吗？我面临着同样的行为