异步加载tableview图片

[roman9t]

看了很多文章，异步加载总是搞不定。下面的代码会在收到json的时候下载全部图片（包括大图和小图），ui线程会很卡，请教改如何修改？感谢。

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data 
{
	// Store incoming data into a string
	NSString *jsonString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
		
	// Create a dictionary from the JSON string
	NSDictionary *results = [jsonString JSONValue];
	
	// Build an array from the dictionary for easy access to each entry
	NSArray *photos = [[results objectForKey:@"photos"] objectForKey:@"photo"];
	
	// Loop through each entry in the dictionary...
	for (NSDictionary *photo in photos)
	{
		// Get title of the image
		NSString *title = [photo objectForKey:@"title"];
		
		// Save the title to the photo titles array
		[photoTitles addObject:(title.length > 0 ? title : @"Untitled")];
        
		NSString *photoURLString = [NSString stringWithFormat:@"http://farm%@.static.flickr.com/%@/%@_%@_s.jpg", [photo objectForKey:@"farm"], [photo objectForKey:@"server"], [photo objectForKey:@"id"], [photo objectForKey:@"secret"]];
		[photoSmallImageData addObject:[NSData dataWithContentsOfURL:[NSURL URLWithString:photoURLString]]];
		
		photoURLString = [NSString stringWithFormat:@"http://farm%@.static.flickr.com/%@/%@_%@_m.jpg", [photo objectForKey:@"farm"], [photo objectForKey:@"server"], [photo objectForKey:@"id"], [photo objectForKey:@"secret"]];
		[photoURLsLargeImage addObject:[NSURL URLWithString:photoURLString]];        
	}
	
	// Update the table with data
	[theTableView reloadData];
	
	// Stop the activity indicator
	[activityIndicator stopAnimating];
    
	[jsonString release];  
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 
{	
	BigPicViewController *bpvc = [[BigPicViewController alloc] init];
    bpvc.array = [photoURLsLargeImage objectAtIndex:indexPath.row];
    [self.navigationController pushViewController:bpvc animated:YES];
    [bpvc release];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{
	UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cachedCell"];
	if (cell == nil)
		cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:@"cachedCell"] autorelease];
	
#if __IPHONE_3_0
	cell.textLabel.text = [photoTitles objectAtIndex:indexPath.row];
	cell.textLabel.font = [UIFont systemFontOfSize:13.0];
#else
	cell.text = [photoTitles objectAtIndex:indexPath.row];
	cell.font = [UIFont systemFontOfSize:13.0];
#endif
	
	NSData *imageData = [photoSmallImageData objectAtIndex:indexPath.row];
	
#if __IPHONE_3_0
	cell.imageView.image = [UIImage imageWithData:imageData];
#else
	cell.image = [UIImage imageWithData:imageData];
#endif
	
	return cell;
}

[yxy353245805]

顶一下。。。。。。。

[roman9t]

就你一个人。。。看来分要是你的了。。

[Quote=引用 1 楼 yxy353245805 的回复:]

顶一下。。。。。。。
[/Quote]

[Matt]

[photoSmallImageData addObject:[NSData dataWithContentsOfURL:[NSURL URLWithString:photoURLString]]];//这个其中的dataWithContentsOfURL才是你需要做异步处理的地方吧,下载需要时间的啊

用NSURLConnection解决

[[NSURLConnection alloc] initWithRequest:[NSURLRequest requestWithURL: url] delegate:self];

另外记得响应NSURLConnection的delegate.
1.didReceiveData
2.didFailWithError
3.connectionDidFinishLoading

[程序员小迷]

// Update the table with data
[theTableView reloadData];

这个是不是要重绘的太多了，导致卡的？

用局部刷新,方法忘记了，在UITableView里，和reloadData类似的局部刷新。

[程序员小迷]

didReceiveData
会被调用很多次吧，
这里你需要判断导致接收了是哪个图片，是否接收完成了，然后再决定是否刷新，刷新哪个cell.