Fix issue viewdidload call while init FlutterViewController

shell/platform/darwin/ios/framework/Source/FlutterEngine.mm

@@ -204,6 +204,10 @@ - (void)setViewController:(FlutterViewController*)viewController {
   }
 }
 
+- (void)attachView {
+  self.iosPlatformView->attachView();
+}
+
 - (void)setFlutterViewControllerWillDeallocObserver:(id<NSObject>)observer {
   if (observer != _flutterViewControllerWillDeallocObserver) {
     if (_flutterViewControllerWillDeallocObserver) {

shell/platform/darwin/ios/framework/Source/FlutterEngine_Internal.h

@@ -44,6 +44,7 @@
 - (FlutterTextInputPlugin*)textInputPlugin;
 - (void)launchEngine:(NSString*)entrypoint libraryURI:(NSString*)libraryOrNil;
 - (BOOL)createShell:(NSString*)entrypoint libraryURI:(NSString*)libraryOrNil;
+- (void)attachView;
 
 @end
 

shell/platform/darwin/ios/framework/Source/FlutterViewController.mm

@@ -63,6 +63,7 @@ @implementation FlutterViewController {
   BOOL _initialized;
   BOOL _viewOpaque;
   BOOL _engineNeedsLaunch;
+  BOOL _isAttchedView;
   NSMutableSet<NSNumber*>* _ongoingTouches;
 }
 
@@ -450,6 +451,13 @@ - (void)viewWillAppear:(BOOL)animated {
     _engineNeedsLaunch = NO;
   }
 
+  if (!_isAttchedView) {
+    FML_DCHECK([_engine.get() viewController] != nil)
+      << "FlutterViewController::viewWillAppear:AttachView ViewController was nil";
+    [_engine.get() attachView];
+    _isAttchedView = YES;
+  }
+
   // Send platform settings to Flutter, e.g., platform brightness.
   [self onUserSettingsChanged:nil];
 

shell/platform/darwin/ios/platform_view_ios.h

@@ -34,6 +34,7 @@ class PlatformViewIOS final : public PlatformView {
 
   fml::WeakPtr<FlutterViewController> GetOwnerViewController() const;
   void SetOwnerViewController(fml::WeakPtr<FlutterViewController> owner_controller);
+  void attachView();
 
   void RegisterExternalTexture(int64_t id, NSObject<FlutterTexture>* texture);
 

shell/platform/darwin/ios/platform_view_ios.mm

@@ -63,21 +63,24 @@
                                                        accessibility_bridge_.reset();
                                                        owner_controller_.reset();
                                                      }] retain]);
+
+    // Do not call `NotifyCreated()` here - let FlutterViewController take care
+    // of that when its Viewport is sized.  If `NotifyCreated()` is called here,
+    // it can occasionally get invoked before the viewport is sized resulting in
+    // a framebuffer that will not be able to completely attach.
+}
 
+void PlatformViewIOS::attachView() {
   if (owner_controller_) {
     ios_surface_ =
-        [static_cast<FlutterView*>(owner_controller.get().view) createSurface:gl_context_];
+        [static_cast<FlutterView*>(owner_controller_.get().view) createSurface:gl_context_];
     FML_DCHECK(ios_surface_ != nullptr);
 
     if (accessibility_bridge_) {
       accessibility_bridge_.reset(
           new AccessibilityBridge(static_cast<FlutterView*>(owner_controller_.get().view), this,
-                                  [owner_controller.get() platformViewsController]));
+                                  [owner_controller_.get() platformViewsController]));
     }
-    // Do not call `NotifyCreated()` here - let FlutterViewController take care
-    // of that when its Viewport is sized.  If `NotifyCreated()` is called here,
-    // it can occasionally get invoked before the viewport is sized resulting in
-    // a framebuffer that will not be able to completely attach.
   }
 }