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NSURLConnection验证

httpresponse httprequest cocoa-touch iphone

2

jcb344 · 技术社区 · 16 年前

我正在尝试验证连接是否成功,但得到了不稳定的结果。当我尝试使用假URL执行同步请求时:

NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

if (responseData)   
    {  
        did_send = TRUE;  
    }   
    else   
    {  
        did_send = FALSE;
    }

它挂了一段时间,最终返回:

 did_send = FALSE;

但是,如果我使用假URL执行异步请求:

NSURLConnection *conn=[[NSURLConnection alloc] initWithRequest:request delegate:self ];
if (conn)   
    {  
        did_send = TRUE;  
    }   
    else   
    {  
        did_send = FALSE;
    }

我得到:

did_send = TRUE;

每一次。我需要让异步请求工作,因为我能够设置超时,并且在请求超时时不必挂起60秒,而默认超时持续时间对于异步请求是不可更改的。有什么想法吗?

2 回复 | 直到 16 年前

1

7

ennuikiller 16 年前

尝试使用nsurlConnection类委托方法 connection:didFailWithError: 这会给你一致的结果。

-(void)getLocationsFromWebService {
    NSLog(@"in getLocationsFromWebService");


    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:TRUE];


    NSURLRequest *theRequest = [NSURLRequest requestWithURL:self.locationsURL cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:100.0];

    NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
    self.requestType = @"GET";
    if (theConnection) {
        _responseData = [[NSMutableData data] retain ];
    } else {

        [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:FALSE];
    }
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {

    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:FALSE]; 
    NSLog(@"in mapviewcontroller");
    NSLog(@"Error connecting - %@",[error localizedDescription]);
    [connection release];
    [_responseData release];
}

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {

    NSHTTPURLResponse *HTTPResponse = (NSHTTPURLResponse *)response;
    NSInteger statusCode = [HTTPResponse statusCode];

    if (404 == statusCode || 500 == statusCode) {
        //[self.controller setTitle:@"Error Getting Parking Spot ....."];
        [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:FALSE];

        [connection cancel];
        NSLog(@"Server Error - %@", [NSHTTPURLResponse localizedStringForStatusCode:statusCode]);
    } else {
        if ([self.requestType isEqualToString:@"GET"])
            [_responseData setLength:0];
    }
}

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    if ([self.requestType isEqualToString:@"GET"])
        [_responseData appendData:data];
}

-(void) connectionDidFinishLoading:(NSURLConnection *)connection {

    if ([self.requestType isEqualToString:@"GET"]) {
        [self parseLocations:_responseData];
        [_responseData release];
    }
    [connection release];

}

2

1

Jonathan Grynspan 16 年前

简单的实例化 NSURLConnection 什么也不做。它创建了该类的一个实例,但没有开始数据传输——对象通常是非零的,即使请求不可能满足。

相反,你的委托对象( self 在您的代码中)需要实现 NSURLConnectionDelegate (它将处理回调,如“传入数据”或“错误条件”),然后必须发送 非连接 实例 -start 消息,它将在执行线程的运行循环上调度它。

有关 NSURLConnectionDelegate(NSURLConnectionDelegate) 协议(包括有关回调操作的信息),请参见Apple的 URL Loading System Programming Guide ."