EXC_BAD_ACCESS错误

我试图读取的图像的EXIF数据，由用户选择。我正在使用ALAssetLibrary。到目前为止，我已经成功地得到所需assetForURL:resultBlock:failureBlock:方法参考URL，但是当我试图与参考URL做任何事情，我收到了EXC_BAD_ACCESS错误。EXC_BAD_ACCESS错误

的URL的NSLog，就在（正确的，因为据我所知）字符串中使用它，结果前：

assets-library://asset/asset.JPG?id=1000000003&ext=JPG

我一直在试图找出这但是，我似乎每次都会陷入死胡同。我必须承认我是新来的Objective-C，所以请随时批评我的代码。

代码（远离完整的类，但我认为它应该是足够了）：

//Class_X.m 

-(void)readExifDataFromSelectedImage:(NSURL *)imageRefURL  
{ 
    void (^ALAssetsLibraryAssetForURLResultBlock)(ALAsset *) = ^(ALAsset *asset) 
    { 
     NSLog(@"Test:Succes"); 
    }; 

    ALAssetsLibrary *myAssetLib; 
    NSLog(@"%@",imageRefURL); 
    [myAssetLib assetForURL:imageRefURL 
       resultBlock:ALAssetsLibraryAssetForURLResultBlock 
       failureBlock:^(NSError *error){NSLog(@"test:Fail");}]; 
} 

//Class_Y.m 
//This also conforms to the UIImagePickerControllerDelegate And the NavigationControllerDelegate protocols: 

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{ 
    self.referenceURL = [info valueForKey:@"UIImagePickerControllerReferenceURL"]; 
    NSString *mediaType = [info 
         objectForKey:UIImagePickerControllerMediaType]; 
    [self dismissModalViewControllerAnimated:YES]; 
    if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) { 
     UIImage *selectedImage = [info objectForKey:UIImagePickerControllerOriginalImage]; 
     imageView.image = selectedImage; 
     btnNoPicture.hidden = YES; 
     btnSelectPicture.hidden = YES; 
     btnTakePicture.hidden = YES; 
     imageView.hidden = NO; 
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Use this image?" 
                 message:@"Are you sure you want to use this image?" 
                 delegate:self 
               cancelButtonTitle:@"No" 
               otherButtonTitles:@"Yes", nil]; 
     [alert show]; 
     [alert release]; 
    } 

} 


-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex 
{ 
    if (buttonIndex == 0) 
    { 
     //Do not use the selected image. 
     imageView.image = nil; 
     imageView.hidden = YES; 
     //Restart picking process 
    } 
    else 
    { 

     // I have an instance variable of type Class_X which i use 
     // throughout this class; let's call this variable "report". 
     // I also have the referenceURL stored as an instance variable. 
     [self.report readExifDataFromSelectedImage:self.referenceURL]; 
    } 

}

来源

2011-05-16 Uxxish

EXC_BAD_ACCESS是最常见的过度释放的对象的（悬摆指针）的结果。由于库异步操作，该方法readExifDataFromSelectedImage:返回之后执行的块，所以imageRefURL可能已经在这一点上释放。尝试retain请求资产前的URL和release它在成功和失败块。

来源

2011-05-16 15:09:32 omz

干杯，即清理我最初的错误。然而，这并创建调用readExifFromSelectedImage方法（当我无论怎么解析的网址相同（EXC_BAD_ACCES）错误，甚至没有一个硬编码[NSURL URLWithString：@“资产库：//asset/asset.JPG ID = 1000000003＆EXT = JPG“] 有关任何建议吗？[self.report]对象是好的，不同的方法正常工作没有错误。在此先感谢:) – Uxxish 2011-05-16 15:28:39

嗯，它看起来像myAssetLib是不确定的。你声明变量，但不要给它赋值... – omz 2011-05-16 15:46:26

令人难以置信的是我如何忽略这一点。谢谢一堆！现在完美的工作！ – Uxxish 2011-05-16 15:48:37

EXC_BAD_ACCESS错误

回答

相关问题