iphone - 获取异步 Twitter 个人资料图片 iOS5

Question

无法弄清楚为什么 profileImage 没有粘住......（我添加了 pImage 只是为了看看它是否与在一个块内......它不是）。

profileImage 只是一个普通的综合属性

@property (strong, nonatomic) UIImageView *profileImage;

-(void)fetchProfileImage
{
    __block UIImage *pImage;

    dispatch_async(dispatch_get_global_queue(0, 0), ^
    {
        NSString *url_ = [NSString stringWithFormat:@"http://api.twitter.com/1/users/profile_image/%@", userName];

        TWRequest *fetchUserImageRequest = [[TWRequest alloc] initWithURL:[NSURL URLWithString:url_] parameters:nil requestMethod:TWRequestMethodGET];

        [fetchUserImageRequest performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) 
         {
             if ([urlResponse statusCode] == 200) 
             {
                 dispatch_async(dispatch_get_main_queue(), ^(void) 
                {
                    NSLog(@"[UIImage imageWithData:responseData] = %@", [UIImage imageWithData:responseData]);

                    pImage = [UIImage imageWithData:responseData];

                    NSLog(@"pImage = %@", pImage);

                    self.profileImage.image = pImage;

                    NSLog(@"self.profileImage.image = %@", self.profileImage.image);

                });
             }
         }];
    });
}

日志：

[UIImage imageWithData:responseData] = <UIImage: 0x2685d0>
pImage = <UIImage: 0x2685d0>
self.profileImage.image = (null)

Answer 1

原来我在创建父对象时没有初始化 UIImageView

tweet.profileImage = [[UIImageView alloc] init];