iOS 上传文件

　　NSString *boundry = @"boundry";//分节符

NSMutableURLRequest *mutableRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"服务器地址"]];

[mutableRequest setHTTPMethod:@"POST"];

NSMutableDictionary *head = [NSMutableDictionary dictionaryWithObjectsAndKeys:[NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundry],@"Content-Type",nil];

[mutableRequest setAllHTTPHeaderFields:head];

NSMutableString *mutableString = [[NSMutableString alloc] init];

[mutableString appendFormat:@"--%@\r\n", boundry];

[mutableString appendFormat: @"Content-Disposition: form-data; name=\"image\"; filename=\"image.png\"\r\n\r\n"];//name + filename 自己看着来，其他就不要换了

NSMutableData *postData = [NSMutableData dataWithCapacity:[imageData length] + 512];

[postData appendData:[mutableString dataUsingEncoding:NSUTF8StringEncoding]];

[postData appendData:imageData];//插入要上传的文件数据（NSData）

[postData appendData:

[[NSString stringWithFormat:@"\r\n--%@--\r\n", boundry] dataUsingEncoding:NSUTF8StringEncoding]];

[mutableRequest setHTTPBody:postData];

NSData *received = [NSURLConnection sendSynchronousRequest:mutableRequest returningResponse:nil error:nil];