Question

我正在尝试创建一个基本应用程序，其中包含人员详细信息并将其发布到私人服务器上。我的网址暂时保持空白，如果我使用NSURLConnectionDelegate并使用didFailWithError，则可以说没有连接，但是当我尝试使用NSLog方法时，它会说

“建立连接”

出于某种原因。这是我的代码

- (void) saveData{
NSString *name = self.NameTextField.text;
NSString *phoneNumber = self.phoneNumberTextField.text;
NSString *age = self.ageTextField.text;
NSString *email = self.emailTextField.text;

//Define the URL
NSURL *url = [[NSURL alloc]initWithString:@""];

//Initialize a request from the URL
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[url standardizedURL]];

//Specify that it will be a post request.
request.HTTPMethod = @"POST";

// This is how we set header fields
[request setValue:@"application/json; charset=utf-8" forHTTPHeaderField:@"Content-Type"];

NSString *DataString = [NSString stringWithFormat:@"name=%@&phonenumber=%@&age=%@&email=%@",name,phoneNumber,age,email];

//Change your requests HTTPBody property
NSData *requestBodyData = [DataString dataUsingEncoding:NSUTF8StringEncoding];
request.HTTPBody = requestBodyData;


// Create url connection and fire request
NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
self.connection = conn;
if(self.connection){
    NSLog(@"Connection is made");
}else{
    NSLog(@"Connection is not made");
}
[self.connection start];
}

如果我的代码中有任何其他错误，请告知。

Answer 1

您的代码检查self.connection变量是否为空，但由于alloc init似乎已成功执行，因此它不是。即对象已创建，这就是您正在检查的对象，无论它是否与您想要的是不同的故事。

Answer 2

if (self.connection)正在做的就是检查nil是否[self.connection start];实际上没有检查是否已在if (self.connection) { NSLog(@"Connection is made"); } else { NSLog(@"Connection is not made"); }处建立连接。基本上是这样的：

if (self.connection != nil) {
    NSLog(@"Connection is made");
} else {
    NSLog(@"Connection is not made");
}

与

完全相同

self.connection

并且nil不是conn，因为您已将NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self]; self.connection = conn;分配给已初始化的HTTP Status。这可以在您的代码下面的两行中看到。

didReceiveResponse:

如果您想检查连接是否成功，可以执行的操作检查- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { switch ([(NSHTTPURLResponse *)response statusCode]) { case 200: { NSLog(@"Received connection response!"); break; } default: { NSLog(@"Something bad happened!"); break; } } }中的{{1}}代码（从Checking for valid IP for connection with NSURLConnection获取的代码）

{{1}}

或如果只是为了了解您是否可以实施Reachability code that Apple supplies或使用其他开源版本。

iOS HTTP POST方法，连接确认

2 个答案: