iphone - NSURLConnection、NSMutableURLRequest 设置范围错误

Question

我正在尝试使用以下方法实现下载恢复功能setValue:forHTTPHeaderField。但每当我使用该方法时，我都会得到一个

[NSURLRequest setValue:forHTTPHeaderField:]: unrecognized selector sent to instance 0x4e0b710 2011-08-08 22:44:36.469 Patch[9140:207] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSURLRequest setValue:forHTTPHeaderField:]: unrecognized selector sent to instance 0x4e0b710'

错误。

如果没有该方法，我的代码可以正常工作，但是当我包含此代码时，我收到上面的错误

NSMutableURLRequest* request = [NSURLRequest requestWithURL:[NSURL URLWithString:URL]
                                         cachePolicy:NSURLRequestUseProtocolCachePolicy
                                     timeoutInterval:60.0];

//---------------- setting range for download resume -----------------------
NSString* range = @"bytes=";
range = [range stringByAppendingString:[[NSNumber numberWithInt:offset] stringValue]];
range = [range stringByAppendingString:@"-"];
NSLog(@"range: %@", range);

[request setValue:range forHTTPHeaderField:@"Range"];

请帮助我...非常感谢

Answer 1

您需要使用 NSMutableURLRequest 创建一个 NSMutableURLRequest。

NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:URL]
                                         cachePolicy:NSURLRequestUseProtocolCachePolicy
                                     timeoutInterval:60.0];