multithreading - 不同线程上的响应回调

Question

回调应该在不同的线程上调用吗？ 使用此代码:

client.ExecuteAsync<List<IngredientDto>>(request, Response =>
    {
        textBox1.Text += Response.Data.Count;
    });

我收到“InvalidOperationException”:

"The calling thread cannot access this object because a different thread owns it."

回调不应该在 UI 线程上吗？还是我错了？

Answer 1

实际上，如果你查看源代码，你就会发现

    public virtual RestRequestAsyncHandle ExecuteAsync<T>(IRestRequest request, Action<IRestResponse<T>, RestRequestAsyncHandle> callback)
    {
        return ExecuteAsync(request, (response, asyncHandle) =>
        {
            IRestResponse<T> restResponse = response as RestResponse<T>;
            if (response.ResponseStatus != ResponseStatus.Aborted)
            {
                restResponse = Deserialize<T>(request, response);
            }

            callback(restResponse, asyncHandle);//<--- this means that response & callback are executed at **same** thread.
        });
    }

这会导致: 您无法从非 ui 线程更新 ui 对象。如果是 WPF，您可以使用 Dispatcher

client.ExecuteAsync<List<IngredientDto>>(request, Response =>
    {
        Dispatcher.Invoke((Action)() => {textBox1.Text += Response.Data.Count;});
    });

一般情况请参见syncronization context