Android dialog显示并且宽度适应屏幕宽度

 /**
     * 视频播放
     *
     * @param context 上下文
     * @return
     */
    public static AlertDialog getvideoplay(final Activity context) {
    
    
        nActivity = context;
        final AlertDialog.Builder builder = new AlertDialog.Builder(context, R.style.DialogStyle);
        View view = View.inflate(context, R.layout.playvideo_dialog, null);
        mVideoview = (MyVideoView) view.findViewById(R.id.video_View);
        mVideoimg = (ImageView) view.findViewById(R.id.video_img);
        mVideotitle = (TextView) view.findViewById(R.id.video_title);
        builder.setView(view);
        final AlertDialog dialog = builder.create();
        dialog.show();

        WindowManager m = context.getWindowManager();
        Display d = m.getDefaultDisplay();  //为获取屏幕宽、高
        android.view.WindowManager.LayoutParams params = dialog.getWindow().getAttributes();  //获取对话框当前的参数值、
        params.width = (int) (d.getWidth());    //宽度设置全屏宽度
        dialog.getWindow().setAttributes(params);     //设置生效

        return dialog;
    }

DialogStyle

 <style name="DialogStyle">
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:windowFrame">@null</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowIsFloating">true</item>
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:windowFullscreen">true</item>
        <item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
        <item name="android:backgroundDimEnabled">true</item>
    </style>