android 自定义 ProgressDialog 在5.0以上出现白色背景的解决方法

<style name="myDialog" parent="@android:style/Theme.Dialog">
<item name="android:windowFrame">@null</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowContentOverlay">@null</item>
<item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
<item name="android:windowSoftInputMode">stateUnspecified|adjustPan</item>
</style>

<style name="myProgressDialog" parent="@style/myDialog">
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowNoTitle">true</item>
</style>

public SimpleProgressDialog(Context context) {
super(context, R.style.myProgressDialog);
this.context = context;
this.setIndeterminate(true);
this.setCancelable(true);
this.getWindow().setGravity(Gravity.CENTER);
}