optimized:

  把XPlatformPlugin进行复用，解决了statusbar在多个activity中显示异常的问题。

.gitignore

@@ -17,3 +17,4 @@ example/android/app/.classpath
 example/android/app/.project
 example/android/.project
 flutter_boost
+.flutter-plugins-dependencies

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

@@ -29,8 +29,8 @@ public class XPlatformPlugin {
     public static final int DEFAULT_SYSTEM_UI = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
             | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
 
-    private  Activity activity;
-    private  PlatformChannel platformChannel;
+    private Activity activity;
+    private PlatformChannel platformChannel;
     private PlatformChannel.SystemChromeStyle currentTheme;
     private int mEnabledOverlays;
 
@@ -96,26 +96,25 @@ public class XPlatformPlugin {
         }
     };
 
-    public XPlatformPlugin( PlatformChannel platformChannel) {
-
+    public XPlatformPlugin(PlatformChannel platformChannel) {
         this.platformChannel = platformChannel;
-
+        this.platformChannel.setPlatformMessageHandler(mPlatformMessageHandler);
         mEnabledOverlays = DEFAULT_SYSTEM_UI;
     }
 
     public void attachToActivity(Activity activity ){
         this.activity = activity;
-        this.platformChannel.setPlatformMessageHandler(mPlatformMessageHandler);
-
     }
+
     /**
      * Releases all resources held by this {@code PlatformPlugin}.
      * <p>
      * Do not invoke any methods on a {@code PlatformPlugin} after invoking this method.
      */
-    public void detachActivity() {
-       this.activity=null;
-       this.mPlatformMessageHandler=null;
+    public void detachActivity(Activity activity) {
+        if (activity == this.activity) {
+            this.activity = null;
+        }
     }
 
     private void playSystemSound(PlatformChannel.SoundType soundType) {

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

@@ -56,6 +56,7 @@ public class BoostFlutterActivity extends Activity
     // Default configuration.
     protected static final String DEFAULT_BACKGROUND_MODE = BackgroundMode.opaque.name();
 
+    private static XPlatformPlugin sXPlatformPlugin;
 
     public static Intent createDefaultIntent(@NonNull Context launchContext) {
         return withNewEngine().build(launchContext);
@@ -440,8 +441,8 @@ public class BoostFlutterActivity extends Activity
 
     @Nullable
     @Override
-    public XPlatformPlugin providePlatformPlugin( @NonNull FlutterEngine flutterEngine) {
-        return new XPlatformPlugin( flutterEngine.getPlatformChannel());
+    public XPlatformPlugin providePlatformPlugin(@NonNull FlutterEngine flutterEngine) {
+        return BoostViewUtils.getPlatformPlugin(flutterEngine.getPlatformChannel());
     }
 
     /**

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

+package com.idlefish.flutterboost.containers;
+
+import com.idlefish.flutterboost.XPlatformPlugin;
+
+import io.flutter.embedding.engine.systemchannels.PlatformChannel;
+
+class BoostViewUtils {
+
+    private static volatile XPlatformPlugin mInstance;
+
+    private BoostViewUtils() {
+    }
+
+    public static XPlatformPlugin getPlatformPlugin(PlatformChannel channel) {
+        if (mInstance == null) {
+            synchronized (BoostViewUtils.class) {
+                if (mInstance == null) {
+                    mInstance = new XPlatformPlugin(channel);
+                }
+            }
+        }
+        return mInstance;
+    }
+}

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

@@ -228,7 +228,7 @@ public class FlutterActivityAndFragmentDelegate implements IFlutterViewContainer
         // Null out the platformPlugin to avoid a possible retain cycle between the plugin, this Fragment,
         // and this Fragment's Activity.
         if (platformPlugin != null) {
-            platformPlugin.detachActivity();
+            platformPlugin.detachActivity(getContextActivity());
             platformPlugin = null;
         }
 

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

@@ -2,8 +2,6 @@ package com.idlefish.flutterboost.containers;
 
 import android.app.Activity;
 import android.arch.lifecycle.Lifecycle;
-import android.graphics.Color;
-import android.view.*;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Build;
@@ -17,13 +15,11 @@ import android.view.View;
 import android.view.ViewGroup;
 
 import com.idlefish.flutterboost.FlutterBoost;
-import com.idlefish.flutterboost.Utils;
 import com.idlefish.flutterboost.XFlutterView;
 import com.idlefish.flutterboost.XPlatformPlugin;
 import io.flutter.embedding.android.*;
 import io.flutter.embedding.engine.FlutterEngine;
 import io.flutter.embedding.engine.FlutterShellArgs;
-import io.flutter.plugin.platform.PlatformPlugin;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -472,8 +468,7 @@ public class FlutterFragment extends Fragment implements FlutterActivityAndFragm
     @Nullable
     @Override
     public XPlatformPlugin providePlatformPlugin( @NonNull FlutterEngine flutterEngine) {
-        return new XPlatformPlugin(flutterEngine.getPlatformChannel());
-
+        return BoostViewUtils.getPlatformPlugin(flutterEngine.getPlatformChannel());
     }
 
     /**