UITableView动态加载图片

iPhone在加载列表时，如果每个等待把所有列表中的数据都加载完在显示相关内容，如果列表中有一些比较大的图片，加载的时间比较长，那么给用户的效果就很差了，下面详细是一种实现动态加载图片的办法：

- (UITableViewCell *)tableView:(UITableView *)tableView 
         cellForRowAtIndexPath:(NSIndexPath *)indexPath { 
    UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:@"tag"]; 
    if (cell==nil) { 
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle 
                                       reuseIdentifier:@"tag"] autorelease]; 
    }    
    NSDictionary* one = [array objectAtIndex:indexPath.row]; 
    cell.textLabel.text = [one objectForKey:@"title"]; 
　　 //延时0.01s后开辟线程
    [self performSelector:@selector(delayToDetachNewThread:) withObject:indexPath afterDelay:0.01];
    return cell; 
}

- (void)delayToDetachNewThread:(NSIndexPath *)indexPath
{
    [NSThread detachNewThreadSelector:@selector(updateImageForCellAtIndexPath:) toTarget:self withObject:indexPath];
}

- (void)updateImageForCellAtIndexPath:(NSIndexPath *)indexPath 
{ 
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; 

    id path = [[array objectAtIndex:indexPath.row] objectForKey:@"image"]; 
    NSURL *url = [NSURL URLWithString:path]; 
    NSData *data = [NSData dataWithContentsOfURL:url]; 
    UIImage *image = [[UIImage alloc] initWithData:data cache:NO]; 

　　 UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath]; 

　　 //主线程中刷新UI
    [cell.imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO]; 
    [image release]; 
    [pool release]; 
} 

GCD动态加载

            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

                NSData *data = [NSDatadataWithContentsOfURL:[NSURLURLWithString:imgPath]];

                UIImage *image = [UIImage imageWithData:data];

                dispatch_async(dispatch_get_main_queue(), ^{

　　　　　　　　　　　　cell.imageView.image = image;

                });

            });