对象删除错误后的序列化(NetDataContractSerializer)

Question

我正在使用NetDataContractSerializer。我可以在数据文件中创建、添加和序列化对象，没有问题；将文件重新加载到GUI中没有问题。

但是，当我尝试从数据中删除(删除)对象并重新保存(序列化)数据时，我遇到了一个问题。

这是我的“删除房间”按钮；当用户请求删除特定楼层上的房间时，程序将创建一个位于该特定楼层的特定房间内的对象列表。然后删除它们，关闭正在查看的当前窗体并保存数据。

这似乎是可行的，因为程序不会崩溃，房间将从当前楼层的房间列表中删除。

但是，当我试图重新加载文件(关闭程序、打开和加载)时，我会得到以下错误：

“反序列化对象时出错。根级的数据无效。第1行，位置1。”。

这是我的deleteRoom按钮

      private void btn_deleteRoom_Click(object sender, EventArgs e)
    {
        var assets = getAssetsForCurrentRoom();
        string warningMessage = "Deleting this room will delete this room and all contained assets! Are you sure you want to do this?";
        string caption = "WARNING!";
        MessageBoxButtons buttons = MessageBoxButtons.YesNo;
        DialogResult result;
        //Display the MessageBox
        result = MessageBox.Show(warningMessage, caption, buttons);
        if (result == System.Windows.Forms.DialogResult.Yes)
        {
            var itemsToRemove = new ArrayList();
            foreach (var item in currentHouse.GetAssets())
            {
                if (item.Parent.Name == currentRoom.Name)
                {
                    itemsToRemove.Add(item);
                }
            }
            foreach (var item in itemsToRemove)
            {
                currentHouse.deleteAsset((Asset)item);
            }
            currentHouse.DeleteRoom(currentRoom);
            PersistanceController.SaveHouseWithCurrentPath(currentHouse);
            this.Close();
        }
    }

下面是方法deleteAsset()的CRUD

public void deleteAsset(Asset asset)
    {
        //is null?
        if (asset == null)
        {
            throw new ArgumentNullException("asset", "Asset cannot be null.");
        }
        //is blank
        if (string.IsNullOrWhiteSpace(asset.Name))
        {
            throw new ArgumentNullException("asset", "Asset name cannot be blank | null.");
        }
        var listAsset = _assets.FirstOrDefault(existingAsset => (existingAsset.Name == asset.Name));
        if (listAsset != null)
        {
            _assets.Remove(asset);
        }
        else
        {
            throw new InvalidOperationException("Asset does not exist; thus it can not be deleted.");
        }
    }

这是我的PersistanceController

 public static class PersistanceController
{

    public static string LastLoadedPath { get; set; }

    public static House LoadHouse(string path)
    {
        NetDataContractSerializer houseDeserializer = new NetDataContractSerializer();

        FileStream houseFileStream = new FileStream(path, FileMode.Open);
        House deserialzedHouse = (House)houseDeserializer.Deserialize(houseFileStream);

        houseFileStream.Close();

        LastLoadedPath = path;

        return deserialzedHouse;
    }

    public static void SaveHouseWithCurrentPath(House house)
    {
        SaveHouse(house, LastLoadedPath);
    }

    public static void SaveHouse(House house, string path)
    {

        //save house
        NetDataContractSerializer xmlSerializer = new NetDataContractSerializer();
        Stream streamWriter = new FileStream(path, FileMode.OpenOrCreate);
        xmlSerializer.Serialize(streamWriter, house);

        streamWriter.Close();
    }
}

Answer 1

我想你的问题可能是FileMode.OpenOrCreate。让它只是FileMode.Create，否则你会有一个不想要的尾巴从原始(更长)文件。

另外，附带的主题是，使用using() {}块来处理FileStreams。