POST file for Mac

post-file.m

NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:url];

[req setHTTPMethod:@"POST"]; // POST 请求
[req  setValue: [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundry] forHTTPHeaderField:@"Content-Type"]; //boundry = 0xKhTmLbOuNdArY；可参考 HTTP 协议
[req setValue: @"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.93 Safari/537.36" forHTTPHeaderField: @"User-Agent"];

NSMutableData *postData = [NSMutableData dataWithCapacity:[data length] + 512]; 
[postData appendData: [[NSString stringWithFormat:@"--%@\r\n", boundry] dataUsingEncoding:NSUTF8StringEncoding]];

[postData appendData: [[NSString stringWithFormat: @"Content-Disposition: form-data; name=\"%@\"; filename=\"%@\"\r\n\r\n", FORM_FLE_INPUT, filename] dataUsingEncoding:NSUTF8StringEncoding]]; // FORM_FLE_INPUT 类似与 <input type="file" name="xxx"> 中的 name 属性值，用来在服务端获取上传的文件，比如 $_FILES['xxx']
[postData appendData:data];
[postData appendData: [[NSString stringWithFormat:@"\r\n--%@--\r\n", boundry] dataUsingEncoding:NSUTF8StringEncoding]];

[req setHTTPBody:postData];