Question

我在iOS上从我的http客户端获取数据时遇到问题。这是我的客户端类代码

@synthesize receivedData;

- (void) HTTPRequest1 :(NSURL *) url {
        NSURLRequest *req = [NSURLRequest requestWithURL: url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];

    NSURLConnection *connect = [[NSURLConnection alloc] initWithRequest:req delegate:self];


    if (connect) {
        receivedData =[NSMutableData data];

    }
    else {

    }


}

-(void) connection:(NSURLConnection*) connection didReceiveResponse:(NSURLResponse *)response{
    [self.receivedData setLength:0];


}

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

        [self.receivedData appendData:data];
    //receivedData

}

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

    NSLog(@"Connection failed! Error - %@ %@",
          [error localizedDescription],
          [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}

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

    NSLog(@"Succeeded! Received %d bytes of data",[receivedData length]);



}

但是当我试图从这个客户端获取数据时：

NSURL *url = [NSURL URLWithString:@"http://ya.ru"];
MAHTTPClient *client = [MAHTTPClient alloc];
[client HTTPRequest1:url];
 NSMutableData *data = client.receivedData;

数据变量为空，但接收到数据（NSLog显示下载一些字节数据的事实）。问题是我的应用程序正在尝试检索尚未从服务器下载的数据（有200毫秒的差异）有没有办法让主线程等到调用connectionDidFinishLoading？

Answer 1

您在此处分配的NSMutableData：

if (connect) {
    receivedData =[NSMutableData data];

}
else {

}

可能正在自动释放，因为您正在使用返回自动释放对象的方法。

您应该执行以下操作：

self.receivedData = [NSMutableData data];

如果receivedData是强/保留属性或

receivedData = [[NSMutableData alloc] init];

//但你需要了解内存管理规则，以确保你没有泄漏内存。

iOS http请求数据恢复

1 个答案: