避免多次调用surfaceUpdate或者反复创建surface

ios/Classes/Engine/FLBFlutterEngine.m

@@ -81,7 +81,6 @@
 - (void)resume
 {
     [[_engine lifecycleChannel] sendMessage:@"AppLifecycleState.resumed"];
-    [(FLBFlutterViewContainer *)_engine.viewController surfaceUpdated:YES];
 }
 
 - (void)inactive
@@ -110,6 +109,7 @@
 - (void)atacheToViewController:(FlutterViewController *)vc
 {
     if(_engine.viewController != vc){
+        [(FLBFlutterViewContainer *)_engine.viewController surfaceUpdated:NO];
         _engine.viewController = vc;
     }
 }
@@ -123,11 +123,9 @@
 
 - (void)prepareEngineIfNeeded
 {
-//    if ([_dummy respondsToSelector:@selector(setEnableForRunnersBatch:)]) {
-//        [_dummy setEnableForRunnersBatch:YES];
-//    }
-    [self detach];
-    [_dummy surfaceUpdated:YES];
+    [(FLBFlutterViewContainer *)_engine.viewController surfaceUpdated:NO];
+    NSLog(@"[XDEBUG]---surface changed--reset-");
+//    [self detach];
 }
 
 @end

ios/Classes/container/FLBFlutterViewContainer.m

@@ -27,6 +27,8 @@
 #import "BoostMessageChannel.h"
 #import "FLBFlutterContainerManager.h"
 #import "FlutterBoostPlugin_private.h"
+#import <objc/message.h>
+#import <objc/runtime.h>
 
 #define FLUTTER_APP [FlutterBoostPlugin sharedInstance].application
 #define FLUTTER_VIEW FLUTTER_APP.flutterViewController.view
@@ -137,7 +139,6 @@ static NSUInteger kInstanceCounter = 0;
 
 - (void)attatchFlutterEngine
 {
-    [FLUTTER_APP.flutterProvider prepareEngineIfNeeded];
     [FLUTTER_APP.flutterProvider atacheToViewController:self];
 }
 
@@ -161,16 +162,6 @@ static NSUInteger kInstanceCounter = 0;
 
 - (void)viewWillAppear:(BOOL)animated
 {
-    if([FLUTTER_APP contains:self]){
-        [self surfaceUpdated:NO];
-        [self detatchFlutterEngine];
-    }else{
-        [self attatchFlutterEngine];
-        [self surfaceUpdated:YES];
-    }
-  
-    [FLUTTER_APP resume];
-    
     //For new page we should attach flutter view in view will appear
     //for better performance.
  
@@ -185,7 +176,13 @@ static NSUInteger kInstanceCounter = 0;
         [FlutterBoostPlugin sharedInstance].fParams = _params;
     }
  
-    [super viewWillAppear:animated];
+    //instead of calling [super viewWillAppear:animated];, call super's super
+    struct objc_super target = {
+        .super_class = class_getSuperclass([FlutterViewController class]),
+        .receiver = self,
+    };
+    NSMethodSignature * (*callSuper)(struct objc_super *, SEL, BOOL animated) = (__typeof__(callSuper))objc_msgSendSuper;
+    callSuper(&target, @selector(viewWillAppear:), animated);
 }
 
 - (void)viewDidAppear:(BOOL)animated
@@ -194,13 +191,15 @@ static NSUInteger kInstanceCounter = 0;
     
     //Ensure flutter view is attached.
     [self attatchFlutterEngine];
-    [FLUTTER_APP resume];
  
     [BoostMessageChannel didShowPageContainer:^(NSNumber *result) {}
                                            pageName:_name
                                              params:_params
                                            uniqueId:self.uniqueIDString];
     
+    //NOTES：务必在show之后再update，否则有闪烁
+    [self surfaceUpdated:YES];
+    
     [super viewDidAppear:animated];
 }
 
@@ -217,14 +216,17 @@ static NSUInteger kInstanceCounter = 0;
 
 - (void)viewDidDisappear:(BOOL)animated
 {
-    [FLUTTER_APP resume];
     [BoostMessageChannel didDisappearPageContainer:^(NSNumber *result) {}
                                                 pageName:_name
                                                   params:_params
                                                 uniqueId:self.uniqueIDString];
-    [super viewDidDisappear:animated];
-    [FLUTTER_APP resume];
-
+//  instead of calling [super viewDidDisappear:animated];, call super's super
+    struct objc_super target = {
+        .super_class = class_getSuperclass([FlutterViewController class]),
+        .receiver = self,
+    };
+    NSMethodSignature * (*callSuper)(struct objc_super *, SEL, BOOL animated) = (__typeof__(callSuper))objc_msgSendSuper;
+    callSuper(&target, @selector(viewDidDisappear:), animated);
 }
 
 - (void)installSplashScreenViewIfNecessary {