11

我是 iphone 开发新手。我已经发布了带有用户名和密码的 URL。我可以在“connection didReceiveData”方法中打印数据。但是我看到“connection didReceiveData”方法被调用了两次。我不知道我哪里出错了。这是我的代码

 - (void)viewDidLoad {
[super viewDidLoad];

NSString *post = [NSString stringWithFormat:@"&domain=school.edu&userType=2&referrer=http://apps.school.edu/navigator/index.jsp&username=%@&password=%@",@"xxxxxxx",@"xxxxxx"];

NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

NSString *postLength = [NSString stringWithFormat:@"%d",[postData length]];

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

[request setURL:[NSURL URLWithString:[NSString stringWithFormat:@"https://secure.school.edu/login/process.do"]]];

[request setHTTPMethod:@"POST"];

[request setValue:postLength forHTTPHeaderField:@"Content-Length"];

[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Current-Type"];

[request setHTTPBody:postData];

NSURLConnection *conn = [[NSURLConnection alloc]initWithRequest:request delegate:self];

if(conn)
{
    NSLog(@"Connection Successful");

}
else
{
    NSLog(@"Connection could not be made");
}

    }

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

NSString *string = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
NSLog(@"the  data %@",string);
  }

整个 HTML 页面在控制台中打印了两次。所以请帮帮我。谢谢。

4

2 回答 2

14

您可能会收到大块的响应数据，这就是NSURLConnection 的文档指出的原因：

“委托应连接交付的每个数据对象的内容，以构建 URL 加载的完整数据。”

为此使用 的实例，NSMutableData并且仅在收到-connectionDidFinishLoading:消息后处理完整的数据。

于 2010-03-15T09:39:11.653 回答
11

正如MacOS 开发人员库所述，如果以块的形式接收数据，则可以多次调用 connection:didReceiveData。这意味着您必须将所有块保存在某个变量中并在 connectionDidFinishLoading 方法中进行数据处理。例如

NSMutableData *receivedData = [[NSMutableData alloc] init];

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    // Append the new data to receivedData.
    [receivedData appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    // do something with the data, for example log:
    NSLog(@"data: %@", [[NSString alloc] initWithData:receivedData encoding:NSUTF8StringEncoding]
}
于 2012-06-06T12:03:22.050 回答