查了一圈，查到了setuploadprogress 这个方法，但是不知道怎么用。
补一下代码吧

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    [manager POST:urlStr parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
        [formData appendPartWithFileData:imgData name:@"pic" fileName:fileName mimeType:@"image/jpeg"];
    } success:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"success:%@",responseObject);
        NSInteger result = [[responseObject objectForKey:@"result"] integerValue];
        if (result == 1) {
            successBlock(responseObject);
        }else{
            UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:nil message:@"出错了" delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];
            [alertView show];
        }

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:nil message:[error localizedDescription] delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];
        [alertView show];
        failureBlock(error);
    }];