解决 多个SurfaceView时候，闪屏的问题

android/src/main/java/com/idlefish/flutterboost/XFlutterView.java

@@ -585,7 +585,6 @@ public class XFlutterView extends FrameLayout {
               + " to new engine.");
       detachFromFlutterEngine();
     }
-    this.requestFocus();
     this.flutterEngine = flutterEngine;
 
     // Instruct our FlutterRenderer that we are now its designated RenderSurface.

android/src/main/java/com/idlefish/flutterboost/containers/FlutterActivityAndFragmentDelegate.java

@@ -5,6 +5,7 @@ import android.app.Activity;
 import android.arch.lifecycle.Lifecycle;
 import android.content.Context;
 import android.content.Intent;
+import android.graphics.PixelFormat;
 import android.os.Build;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
@@ -102,6 +103,8 @@ public class FlutterActivityAndFragmentDelegate  implements IFlutterViewContaine
 
 
         host.configureFlutterEngine(flutterEngine);
+
+        host.getActivity().getWindow().setFormat(PixelFormat.TRANSLUCENT);
     }