iphone多线程汇总

1,NSThread

- (void)updateImageForCellAtIndexPath:(NSIndexPath *)indexPath
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
UIImage *image = [self getImageForCellAtIndexPath:indexPath];
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
[cell.imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];
[pool release];
}

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
[NSThread detachNewThreadSelector:@selector(updateImageForCellAtIndexPath:) toTarget:self withObject:indexPath];
}

2NSOperation

首先是建立NSOperationQueue和NSOperations。NSOperationQueue会建立一个线程，每个加入到线程operation会有序的执行。

NSOperationQueue *queue = [NSOperationQueue new];

NSInvocationOperation *operation = [[NSInvocationOperation alloc];

initWithTarget:self

selector:@selector(doWork:)

object:someObject];

[queue addObject:operation];

[operation release];

下面是使用NSOperationQueue的过程：

1. 建立一个NSOperationQueue的对象
2. 建立一个NSOperation的对象
3. 将operation加入到NSOperationQueue中
4. release掉operation

使用NSOperation有几种,现在介绍最简单的一种NSInvocationOperation，NSInvocationOperation是NSOperation的子类，允许运行在operation中的targer和selector

3NSURLConnection

如果你是网络应用使用NSURLConnection的异步代理无意是最简便的解决方案