通过NSURLConnection下载文件

本文介绍通过NSURLConnection对网上的文件或者图片进行下载，先看代码:

//@property (nonatomic,strong) NSMutableData *mutableData;

    NSURL *url = [NSURL URLWithString:[self.updateContentDict valueForKey:@"commons"]];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];

    [request setURL:url];

    [request setHTTPMethod:@"GET"];//设置请求方式

    [request setTimeoutInterval:30];//设置超时时间

    self.mutableData = [[NSMutableData alloc] init];

    [self.view makeToast:@"app下载中..."];

    [NSURLConnection connectionWithRequest:request delegate:self];//发送一个异步请求

注意Controller需要实现代理方法：NSURLConnectionDataDelegate

#pragma mark - NSURLConnection delegate

//数据加载过程中调用,获取数据

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {

//把数据添加进一个属性

    [self.mutableDataappendData:data];

    NSLog(@"%@",self.mutableData);

}

//数据加载完成后调用

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

    [selfdismissHUD];

    [self.viewmakeToast:@"下载完成"];

}

//数据请求失败的时候调用

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {

    NSLog(@"请求网络失败:%@",error);

}