Question

编辑：解决了。我忘了在viewDidLoad方法中使用委托对象。检查代码和注释，看看我的意思。

这是一个复杂的问题，我之前曾问过。我正在尝试使用NSURLConnection（我必须使用）下载图像并将其放在iPhone屏幕上。我有一个名为ImageModel的子视图，它有使用NSURLConnection的方法，我在viewController中有另一个应该显示图像的方法。这是代码：

#import "ImageModel.h"

@implementation ImageModel
@synthesize delegater, receivedData, image;

-(void)initer
{

    NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.gusto-graphics.com/updates/wp-content/uploads/2011/02/SENSE__This_picture_makes_none_by_Mathan552.jpg"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
    NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
    if (theConnection) {
        receivedData = [[NSMutableData data] retain];
    } else {
        NSLog(@"Connection Failed.");           
    }
}

//There's a few connection methods after this method, which I didn't really change.

-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    image = [UIImage imageWithData:receivedData];

    [delegater performSelectorOnMainThread:@selector(didFinishDownload:) withObject:image waitUntilDone:NO];

    NSLog(@"Success. Received %d bytes of data", [receivedData length]);

    [connection release];
    [receivedData release];
}

@end

receivedData，delegater和image都在头文件中声明，并且还有一个协议需要调用一个名为didFinishDownload的方法。

我将此代码放在视图控制器中：

- (void)didFinishDownload:(UIImage*)image {
    imageView.image = image;
    [imageView setNeedsDisplay];
}

- (void)viewDidLoad {
    model = [[ImageModel alloc] init];
    [model initer];
    [super viewDidLoad];
}

模型和imageView都在头文件中声明，我确保将imageView附加到界面构建器中的实际UIImageView，我甚至检查过以确保图片仍然出现在网站上。尽管如此，我所得到的只是一个灰色屏幕。有人可以帮忙吗？

Answer 1

解决。我忘了在viewDidLoad方法中使用委托对象。

无法在Xcode中显示图像

1 个答案: