的iOS的UIImageView不显示图像

我在我的应用双视图控制器，一个控制器捕捉使用AVCapturSession的iOS的UIImageView不显示图像

我写这一张照片，

[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) 
{ 
    CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL); 
    if (exifAttachments) 
    { 
     // Do something with the attachments. 
     NSLog(@"attachements: %@", exifAttachments); 
    } 
    else 
     NSLog(@"no attachments"); 

    NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer]; 
    UIImage *displayimage = [[UIImage alloc] initWithData:imageData]; 

    SecondViewController *sec = [[SecondViewController alloc]init]; 
    sec.showTakenPic.image = displayimage; 
    [self.navigationController pushViewController:sec animated:YES]; 
}];

的SecondViewController包含一个UIImageView其图像I我设置为显示图像，但图像未设置。

我SecondViewController从故事板制作，

的SecondViewController.h看起来是这样的，

#import <UIKit/UIKit.h> 

@interface SecondViewController : UIViewController 

@property(atomic,retain) IBOutlet UIImageView *showTakenPic; 

@end

的SecondViewController.m看起来是这样的，

#import "SecondViewController.h" 

@interface SecondViewController() 

@end 

@implementation SecondViewController 

-(void)viewDidLoad { 
[super viewDidLoad]; 
[self.navigationController setNavigationBarHidden:YES animated:YES]; 
} 

-(void)didReceiveMemoryWarning { 
    [super didReceiveMemoryWarning]; 
// Dispose of any resources that can be recreated. 
} 

@end

该图像是不可见的在UIImageView中为什么？

来源

2016-03-02 Avinash Sharma

尝试此

你必须先加载从故事板

控制器

Instantiating a View Controller programmatically with Storyboard from AppDelegate

集标识符按本图像

UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main_iPhone" bundle: nil]; 
SecondViewController *controller = (SecondViewController *)[mainStoryboard instantiateViewControllerWithIdentifier: @"SecondViewController"];

然后

dispatch_async(dispatch_get_main_queue(), ^{ 
    sec.showTakenPic.image = displayimage; 
});

这是主线程问题

选择-2

if (imageData) 
{ 
UIImage *displayimage = [[UIImage alloc] initWithData:imageData]; 

SecondViewController *sec = [[SecondViewController alloc]init]; 
sec.showTakenPic.image = displayimage; 
[self.navigationController pushViewController:sec animated:YES]; 
}

来源

2016-03-02 12:24:58 techloverr

@安布。Karthik先生，showTakenPic是IBOutlet，他必须从故事板强制加载 – techloverr

我同意你的观点，也认为这种情况下，'imageData'转换页面之前导航也不会出现图像 –

我的SecondViewController不是一个导航控制器，所以我可以像这样推动它？ –

首先检查，如果图像是不为零。第二，尝试按下视图控制器后设置图像。

if (displayimage) 
{ 
    SecondViewController *sec = [[SecondViewController alloc]init]; 
    [self.navigationController pushViewController:sec animated:YES]; 
    sec.showTakenPic.image = displayimage; 
    sec.showTakenPic.backgroundColor = [UIColor redColor]; 
} 
else 
{ 
    NSLog(@"displayimage is nill"); 
}

来源

2016-03-02 12:43:41

显示图像不是零，但即使设置图像UIImageView显示无 –

你试过我的代码？ –

是的，仍然给我一个黑屏 –

图像有多大，颜色是多少？如果图像比UIImageView大，并且ContentMode属性设置不正确，则可能只会看到图像的黑色部分。

来源

2016-03-02 12:58:10 Boris88

尝试在SecondViewController加载到内存时尝试设置图像。采用类型为UIImage的ivar，并且当推入堆栈的控制器使用ivar在showTakenPic imageView上设置图像时。

UIStoryboard mainStoryboard = [UIStoryboard storyboardWithName:@"Main_iPhone" bundle: nil]; 
SecondViewController *controller = (SecondViewController *) 
[mainStoryboard instantiateViewControllerWithIdentifier:@"SecondViewController"]; 
controller.imageToSet = imagePickedFromFirstController 
[self.navigationController pushViewController:controller];

您可以添加此代码到viewDidLoad中或SecondViewController

self.showTakenPic.image = self.imageToSet

的viewWillAppear中

，或者你正在使用SEGUE什么！

来源

2016-03-02 13:01:48

您应该将图像间接设置到第二个视图控制器中。

FirstViewController.m 

SecondViewController *postImageViewController = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil]; 

[postImageViewController setImage:image]; 

SecondViewController.h 

@interface SecondViewController : UIViewController { 

    UIImage * postImage; 
} 

@property (weak, nonatomic) IBOutlet UIImageView *imageView; 

- (void)setImage:(UIImage*)image; 

@end 

SecondViewController.m 

- (void)viewWillAppear:(BOOL)animated { 

    if(postImage) { 

     _imageView.image = postImage; 

    } 

} 

- (void)setImage:(UIImage*)image { 

    postImage = image; 

}

来源

2017-05-03 09:14:57

的iOS的UIImageView不显示图像

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