fix iOS11截屏慢导致打开大图慢的问题

Author: guangyao

ios/RCTAuroraIMUI/DWShowImageVC.m

@@ -30,7 +30,7 @@ - (void)viewDidLoad {
     [super viewDidLoad];
     UIWindow *screenWindow = [[UIApplication sharedApplication] keyWindow];
     [self.view addSubview:self.backImageView];
-    self.backImageView.image = self.backgroundImg;
+//    self.backImageView.image = self.backgroundImg;
 
     _scroll = [DWOrigScorllView scrollViewWithDataArr:_imageArr andIndex:(_index-1) showDownBtnTime:0.3 ];
     _scroll.delegate = self;

ios/RCTAuroraIMUI/RCTMessageListView.m

@@ -410,8 +410,9 @@ - (void)clickShowOrigImgView:(NSNotification *)noti{
                 UIWindow *win = [UIApplication sharedApplication].keyWindow;
                 UIViewController *rootVC = win.rootViewController;
                 DWShowImageVC *vc = [[DWShowImageVC alloc]init];
+                vc.modalPresentationStyle = UIModalPresentationOverCurrentContext;
                 vc.imageArr = _imageArr;
-                vc.backgroundImg = [self getScreenshots];
+//                vc.backgroundImg = [self getScreenshots];
                 vc.index = imgIndex;
                 [rootVC presentViewController:vc animated:NO completion:nil];
             }