AFNetworking上传图片问题

我先从相册选取一张图片存到本地   

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
// 把头像图片存到本地
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:[NSString stringWithFormat:@'1.jpg']];   // 保存文件的名称
NSData *imageData = UIImageJPEGRepresentation(image, 0.5);
    [imageData writeToFile:filePath atomically:YES];
}


然后通过AFNetworking上传图片到服务器，  
- (void)uplodeUserImage {

    [self.loadingView show];
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];

    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObject:@'text/html'];
    NSDictionary *parameters =@{@'clientId':[_user objectForKey:@'CLIENT_ID']};

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0]; //path数组里貌似只有一个元素
    NSString *filestr = @'/1.jpg';
    NSString *newstr = [documentsDirectory stringByAppendingString:filestr];
NSData *dd = [NSData dataWithContentsOfFile:newstr];
// 加载头像
userImageSupView.image = [UIImage imageWithData:dd];

    [manager POST:[NSString stringWithFormat:@'%@MobileVIPCenter/UpdateClientHead', Data_Http] parameters:parameters constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {

        [formData appendPartWithFileData:dd name:@'1' fileName:@'1.jpg' mimeType:@'image/jpeg'];

    } success:^(AFHTTPRequestOperation *operation,id responseObject) {
        [self.loadingView hide];
        NSLog(@'Success: %@', [responseObject objectForKey:@'msg']);
    } failure:^(AFHTTPRequestOperation *operation,NSError *error) {
        NSLog(@'Error: %@', error);
    }];

}


为什么服务器一直返回给我  请让我选择上传文件呢？？  各位大神帮帮忙。