NSUrlConnectionDelegate不调用方法来加载数据

问题描述：

我已经看过NSURLConnectionDelegate连接：didReceiveData不工作了，但似乎没有要与任何好的结果，所以我很好奇，为什么我不能够获得任何数据。

I have looked at NSURLConnectionDelegate connection:didReceiveData not working already, but there didn't seem to be any good result from that, so I am curious why I am not able to get any data.

我把断点 didReceiveResponse 和 didReceiveData code>。

它打印出连接成功，所以我知道该连接已启动。

It does print out "connection succeeded", so I know that the connection is started.

我使用ARC进行内存管理。

I am using ARC for memory management.

- (void)load {
        request = [NSMutableURLRequest requestWithURL:myURL
                                                           cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
                                                       timeoutInterval:60];

    NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self];
    if (conn) {
        [conn start];
        NSLog(@"connection succeeded, %s", [myURL description]);  
        responseData = [NSMutableData data];
    } else {
        NSLog(@"connection failed");
    }
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    responseData = [[NSMutableData alloc] init];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [responseData appendData:data];
}

更新：

要看看我如何测试这个看Asynchronous单元测试不被SenTestCase 调用。

To see how I test this look at Asynchronous unit test not being called by SenTestCase.

我没有落实jonkroll提到的两种方法，在他的回答，我只是没有告诉他们，但他们也没有被调用。

I did implement the two methods mentioned by jonkroll, in his answer, I just didn't show them, but, they also aren't being called.

我已经加入 [康恩开始] 不仅是因为它不工作，我希望可以解决这个问题，但没有这样的运气。

I had added [conn start] only because it wasn't working, and I was hoping that may solve it, but no such luck.

答

在声明连接是这样的：

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

您正在创建一个本地指针。当你的方法完成，因为这是最后强烈参考 NSURLConnection的， ARC 释放它。你需要使用一个强大的伊娃（和/或）财产持有强有力的参考 NSURLConnection的创建。

You are creating a local pointer. When your method completes, since it was the last strong reference to the NSURLConnection, ARC releases it. You need to use a strong ivar (and/or) property to hold a strong reference to the NSURLConnection you create.

修改

下面是我在一个示例项目测试code的基本样本。给它一个运行。详细日志记录帮助。

Here is basic sample of code that I tested in a sample project. Give it a run. Verbose logging helps.

@implementation <#Your class here#> {
    // With ARC ivars are strong by default 
    NSMutableData *_downloadedData;
    NSURLConnection *_connection;
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{
    NSHTTPURLResponse *realResponse = (NSHTTPURLResponse *)response;
    if (realResponse.statusCode == 200){ 
        // Really any 2** but for example
        _downloadedData = [[NSMutableData alloc] init];
        NSLog(@"Good response");
    } else {
        NSLog(@"Bad response = %i",realResponse.statusCode);
    }
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
    if (connection == _connection){
        [_downloadedData appendData:data];
        NSLog(@"Getting data...");
    }
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
    if (connection == _connection){
        _connection = nil;
        NSLog(@"We're done, inform the UI or the delegates");
    }
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{
    _connection = nil;
    NSLog(@"Oh no! Error:%@",error.localizedDescription);
}
- (void)load {
    NSURL *url = [NSURL URLWithString:@"http://www.google.com/"];
    NSURLRequest *request = [NSMutableURLRequest requestWithURL:url
                                      cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
                                  timeoutInterval:60];
    // Assign strong pointer to new connection
    _connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
    NSLog(@"Connection was initialized? = %@",(!!_connection)?@"YES":@"NO");
}
@end

NSUrlConnectionDelegate不调用方法来加载数据

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