Question

我有Stack<Query>，其中Query如下：

public class Query
{
    private readonly IEnumerable<string> _distinguishedNames;
    private readonly string _searchText;

    private CancellationTokenSource _cancellationTokenSource;

    public Query(
        QueryType queryType,
        Scope scope = null,
        IEnumerable<string> distinguishedNames = null,
        string searchText = null)
    {
        QueryType = queryType;
        Scope = scope;
        _distinguishedNames = distinguishedNames;
        _searchText = searchText;
    }

    private CancellationToken CancellationToken
        => _cancellationTokenSource.Token;

    public Scope Scope { get; }

    public IEnumerable<ExpandoObject> Data { get; private set; }

    public QueryType QueryType { get; }

    public void Cancel()
    {
        _cancellationTokenSource?.Cancel();
    }

    public void DisposeData()
    {
        Data = null;
    }

    public async Task Execute()
    {
        _cancellationTokenSource = new CancellationTokenSource();

        var task = Task.Run(() =>
        {
            Data = new Searcher(
                QueryType,
                Scope,
                _distinguishedNames,
                CancellationToken,
                _searchText).GetData();
        },
        _cancellationTokenSource.Token);
        await task;
    }

    public override string ToString()
    {
        return QueryType.ToString();
    }
}

管理查询的类包含以下相关部分：

Stack<Query> Queries = new Stack<Query>();

private async void ExecuteRunPreviousQuery()
{
    Queries.Pop();
    await RunQuery(Queries.Pop());
}

private async Task RunQuery(
    QueryType queryType,
    Scope scope = null,
    IEnumerable<string> selectedItemDistinguishedNames = null,
    string searchText = null)
{
    await RunQuery(
        new Query(
            queryType,
            scope,
            selectedItemDistinguishedNames,
            searchText));
}

private async Task RunQuery(Query query)
{
    StartTask();
    try
    {
        Queries.Push(query);
        await Queries.Peek().Execute();
        Data = Queries.Peek().Data.ToDataTable().AsDataView();
        ContextMenuItems = GenerateContextMenuItems();
    }
    catch (NullReferenceException e)
    {
        ShowMessage(e.Message);
        ResetQuery();
    }
    catch (OperationCanceledException)
    {
        ShowMessage("Operation was cancelled.");
        ResetQuery();
    }
    catch (ArgumentNullException)
    {
        ShowMessage(
            "No results of desired type found in selected context.");
        ResetQuery();
    }
    catch (OutOfMemoryException)
    {
        ShowMessage("The selected query is too large to run.");
        ResetQuery();
    }

    FinishTask();
}

我可以正常运行任何查询，但如果我尝试运行上一个查询方法，则查询始终将其_distinguishedNames字段设置为空，即使该字段以前有内容。不是空的，只是某种程度上是空的。传递Searcher的{{1}}类不会操纵它;搜索者只是迭代它。我甚至尝试传递_distinguishedNames的副本只是为了确保搜索者不会以某种方式搞乱它，并且这并没有改变任何东西。

为了澄清，我使用_distinguishedNames参数和非空RunQuery来调用QueryType。它执行没有问题。然后，我再次使用其他一些参数调用IEnumerable<string>，然后再次执行而没有问题。然后我调用RunQuery并且第一个查询无法正常运行，因为应该存储在ExecuteRunPreviousQuery中的IEnumerable<string>现在为空。

如果您想查看其他任何代码，请告诉我们。据我所知，这是一个MCVE。

存储在堆栈中的对象具有字段＆＃34;擦除＆＃34;

0 个答案: