异步POST到服务器 [英] Asynchronous POST to server

问题描述

我们的目标是通过查询数据库做一个简单的用户名/密码认证。直到连接工作体面我的PHP目标文件只是有以下code：

The goal is to do a simple username/password authentication by querying a database. Until the connection is working decently my php destination file simply has following code:

echo "Posted: " . $_POST['email'];

在code做这个同步是这样的：

The code to do this synchronously is this:

NSString *post = [[NSString alloc] initWithFormat:@"email=%@&password=%@", self.email.text, ..]; // .. simplified keychainItem
NSData *postEncoded = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:NO];
NSString *postLength = [NSString stringWithFormat:@"%d", [postEncoded length]];

NSURL *url = [NSURL URLWithString:@"http://eng.studev.groept.be/web2.0/a11_web02/improver/app/testPost"];

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:url];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postEncoded];

NSError *error = nil;
NSURLResponse *response = nil;
NSData *encodedData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

NSString *data=[[NSString alloc]initWithData:encodedData encoding:NSUTF8StringEncoding];
NSLog(@"Data? %@",data);

的正确值显示为回声。但是，试图以异步方式做到这一点的时候，我得到下面的PHP错误：未定义指数：电子邮件。
我试着开始与该行的异步请求：

The correct value is shown as an echo. But when trying to do this asynchronously, I get following php error: "Undefined index: email". I try to start the asynchronous request with this line:

[[NSURLConnection connectionWithRequest:request delegate:self] start];

然后，我委托方法连接：didReceiveResponse，但我似乎无法获取数据了......或者我需要另一个委托方法？此外，如何'安全'是只用回声检查您的查询的结果（我需要/想流也许？）??

Then, I have the delegate method connection:didReceiveResponse, but there I cannot seem to get the data out... Or do I need another delegate method? Also, how 'safe' is it to check the result of your query by using just an echo (do I need/want a stream maybe?) ??

蒂亚

修改

问题涉及到服务器，而不是客观-C code。问了一个新的问题，以达到正确的观众： $ _ POST剩余空

Problem related to the server, not to objective-C code. Asked a new question to reach the correct audience: $_POST remaining empty

推荐答案

@ott是在正确的轨道上，我会尽力澄清。

@ott is on the right track, I'll try to clarify.

1. 您不需要启动他说。这是良性的作为连接将自动启动。

1. You don't need start as he says. It's benign as the connection will start automatically.

initWithRequest：委托和 connectionWithRequest：委托：是除了新的保留状态相当于连接对象。

initWithRequest:delegate and connectionWithRequest:delegate: are equivalent except for the retain state of the new connection object.

真正的问题是B / C您使用 connectionWithRequest：委托返回的连接在运行循环结束时自动释放，你是不是保留它在属性。因此，连接永远不会发生。

The real problem is b/c you are using connectionWithRequest:delegate the returned connection is autoreleased at the end of the run loop and you are not retaining it in a property. Therefore, the connection never starts.

该解决方案是增加一个属性 @属性（非原子，保留）NSURLConnection的*从到您的类并将此属性设置为连接>连接​​：withRequest：

The solution is to add a property @property (nonatomic, retain) NSURLConnection *connection to your class and set this property to the connection returned from connection:withRequest:

您再松开在完井方式连接连接：didFinishLoading 和连接：didFailWithError：

You then release the connection in the completion methods connection:didFinishLoading and connection:didFailWithError:.

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