Question

使用代理

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

下载大小可以通过以下方式获取：

downloadSize = [response expectedContentLength];

但我的downloadSize有时是-1。有时它是正确的值，但有一半时间返回-1。

stackoverflow上的这个答案显示了一个可能的解决方案，并解释了为什么我得到值-1：why [response expectedContentLength] always return -1。

我试过了：

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:_downloadURL] cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:60];
[request setValue:@"" forHTTPHeaderField:@"Accept-Encoding"]; //Don't use Gzip to see total size of download

但这并没有改变一件事。有谁知道为什么expectedContentLength给我值-1？再次它只给我一半的时间我尝试。有时它是oke。

修改当我使用代码

时，我在DidReceiveResponse中记录了[response AllHeaderFiles]

[request setValue:@"" forHTTPHeaderField:@"Accept-Encoding"];

"Content-Type" = "text/html";
Date = "Mon, 16 Sep 2013 12:43:54 GMT";
Server = "Apache/2";
"Transfer-Encoding" = Identity;
Vary = "Accept-Encoding,User-Agent";
"X-Powered-By" = "PHP/5.2.17";

这是没有该代码的输出：

Connection = "keep-alive";
"Content-Encoding" = gzip;
"Content-Length" = 1500;
"Content-Type" = "text/html";
Date = "Mon, 16 Sep 2013 12:38:56 GMT";
Server = "Apache/2";
Vary = "Accept-Encoding,User-Agent";
"X-Powered-By" = "PHP/5.2.17";

但是无论我得到-1还是下载大小，两个输出都保持不变。

使用nsurlconnection获取下载大小

0 个答案: