iphone - 如何连接到需要用户名和密码的网站

Question

我有一个基本问题，我希望有一个我错过的简单答案。基本前提是我要连接到一个网站并下载一些 JSON 数据。我使用的是 Stig Brautaset 提供的框架，教程效果非常好。

我的问题是我要连接的网站采用格式，用户名和密码对于我的应用程序是固定的，因此用户永远不会输入它们。

curl -u username:password http://website.com/page

如何将 url 和密码传递给 NSURLConnection？

它不一定是 NSURLConnection，它似乎是最好的选择。

我已经查看了 AdvancedUrlConnections 示例，但它似乎过于复杂并且相当陈旧。在网络上搜索也好不到哪里去。我希望你们中的一个人可以说只需设置这 2 个属性，然后当然是适当的侮辱......

Answer 1

NSURLConnection 会工作得很好。正如在另一个答案中指出的那样，实现 didReceiveAuthenticationChallenge 回调非常容易。

- (void) someMethod
{
    NSURLRequest* request = [[NSURLRequest alloc] 
         initWithURL:[NSURL urlWithString:@"someURL"]

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

    [connection release];
    [request release];
}

这一切都非常简单。所有魔法都在 NSURLConnection 的委托(delegate)方法中发生:

这是您处理凭据质询的地方。我硬编码了一个假的用户名和密码来演示它是如何工作的。我个人有一个单独的委托(delegate)对象来处理挑战。请记住，连接将处于空闲状态，直到您响应它或直到连接超时。

- (void) connection:(NSURLConnection *)connection 
      didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
    //  Make sure to use the appropriate authentication method for the server to
    //  which you are connecting.
    if ([[challenge protectionSpace] authenticationMethod] == 
             NSURLAuthenticationMethodBasicAuth)
    {
            //  This is very, very important to check.  Depending on how your 
            //  security policies are setup, you could lock your user out of his 
            //  or her account by trying to use the wrong credentials too many 
            //  times in a row.
        if ([challenge previousFailureCount] > 0)
        {
            [[challenge sender] cancelAuthenticationChallenge:challenge];

            UIAlertView* alert = [[UIAlertView alloc] 
                            initWithTitle:@"Invalid Credentials" 
                                  message:@"The credentials are invalid." 
                                 delegate:nil 
                        cancelButtonTitle:@"OK" 
                        otherButtonTitles:nil];
            [alert show];
            [alert release];      
        }
        else
        {
            [challenge useCredential:[NSURLCredential 
                   credentialWithUser:@"someUser" 
                             password:@"somePassword" 
                          persistence:NSURLCredentialPersistenceForSession 
           forAuthenticationChallenge:challenge]];
        }
    }
    else
    {
        //  Do whatever you want here, for educational purposes, 
            //  I'm just going to cancel the challenge
        [[challenge sender] cancelAuthenticationChallenge:challenge];
    }
}

您还需要为 NSURLConnection 实现这些其他方法:

//  So you know when it's done downloading
- (void) connectionDidFinishLoading:(NSURLConnection *)connection;
//  In case of failure
- (void) connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;    
//  Gather the downloaded file data
- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;