僵尸杀了我的应用程序

Question

我正在实现异步图像加载UITableView,如果我快速滚动行,我的应用程序因为发送给僵尸的消息而崩溃...我在这里做错了什么？

//loading image from URL
-(void)loadImageFromURL:(NSURL*)url {
    if (connection!=nil) { [connection release]; }
    //data is NSMutableData
    if (data!=nil) { [data release]; }

    NSURLRequest* request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
    connection = [[NSURLConnection alloc] initWithRequest:request delegate:self]; 
}

//Append received data when it is received
- (void)connection:(NSURLConnection *)theConnection didReceiveData:(NSData *)incrementalData {
    if (data==nil) { data = [[NSMutableData alloc] init]; } 
        [data appendData:incrementalData]; //Message sent to zombie, app CRASHES HERE
}

//When finished
- (void)connectionDidFinishLoading:(NSURLConnection*)theConnection {
    //so self data now has the complete image 
    [connection release];
    connection=nil;
    //Use received data to construct image
    [data release]; 
    data=nil;
}

Answer 1

这里:

if (connection!=nil) { [connection release]; }
if (data!=nil) { [data release]; }

你正在发布数据.稍后您尝试使用已发布的数据,以便崩溃.试试这个:

if (connection!=nil) { [connection release]; connection = nil; }
if (data!=nil) { [data release]; data = nil; }

这样你的if陈述实际上会触发.