iphone - 不调用 NSurl 连接委托

Question

这是我从 url 获取图像的代码，但没有调用委托方法。为什么？

NSString *urlLink = [NSString stringWithString:appRecord.imageURLString];   
self.urlString=urlLink;
NSURL *url=[NSURL URLWithString:urlLink];
NSMutableURLRequest *request=[[NSMutableURLRequest alloc] initWithURL:url];
NSURLConnection *conn=[[NSURLConnection alloc] initWithRequest:request delegate:self];
self.imageConnection=conn;
[conn release];

Answer 1

试试这个来检查连接是否为零

 xmlConnection = [[NSURLConnection alloc] 
                 initWithRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@", URL]]] delegate:self];
if (xmlConnection == nil){
    NSLog(@"Connection Error");
}
else{

    responseData = [[NSMutableData alloc] retain];

}