-(void)upload_attach:(NSData *)data fileName:(NSString *)filename mimeType:(NSString *)mtype {
    AFHTTPClient *httpClient;
    MBProgressHUD *hud = [[MBProgressHUD alloc] initWithView:self.view];
    [Tool showHUD:NSLocalizedString(@"正在上传",nil) andView:self.view andHUD:hud];
    NSString *userId = [[Config Instance] getUserName];
    NSArray *userId_arr = [userId componentsSeparatedByString:@"_"];
    NSString *username = [userId_arr objectAtIndex:0];
    NSString *company_id = [userId_arr objectAtIndex:1];
    NSDictionary *para = [NSDictionary dictionaryWithObjectsAndKeys:self.groupName, @"groupname",username,@"username", company_id, @"company_id",filename, @"filename",nil];
    NSLog(@"para:%@", para);
    NSString *serverAddr = [Config Instance].getServAddr;
    NSString *upload_path = [NSString stringWithFormat:@"%@/index.php/ofctrl/upload_attach", BasePath];
    NSURL *url = [NSURL URLWithString:serverAddr];
    httpClient = [[AFHTTPClient alloc] initWithBaseURL:url];
    NSMutableURLRequest *request = [httpClient multipartFormRequestWithMethod:@"POST" path:upload_path parameters:para constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
        [formData appendPartWithFileData:data name:@"uploadfile" fileName:filename mimeType:@"image/png"];
    }];
    [request setTimeoutInterval:30];
    AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:request];
    [op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"upload success!%@", (NSString *)responseObject);
        [hud hide:YES];
        //[self loadData];
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"upload failed:%@", error);
        [hud hide:YES];
    }];
    //[httpClient.operationQueue addOperation:op];
    [op start];
};=====对应的PHP接收参数为

array (
  ‘uploadfile‘ =>
  array (
    ‘name‘ => ‘20150128163845.png‘,
    ‘type‘ => ‘image/png‘,
    ‘tmp_name‘ => ‘C:\\WINDOWS\\Temp\\php70.tmp‘,
    ‘error‘ => 0,
    ‘size‘ => 12767720,
  ),