Question

以下是我用于通过Silverlight从SharePoint 2010检索当前用户名的代码：

ClientContext clientContext = ClientContext.Current;
if (clientContext == null)
{
    SharepointUser = "[Unknown]";
}
else
{
    MessageBox.Show("Beginning server query now...");
    clientContext.Load(clientContext.Web, s => s.CurrentUser);
    clientContext.ExecuteQueryAsync((s, e) =>
    {
        MessageBox.Show("RESPONSE!");
        SharepointUser = clientContext.Web.CurrentUser.LoginName;
        MessageBox.Show("Hello, " + SharepointUser + "!");
    },
    (s, e) =>
    {
        MessageBox.Show("An error occurred: " + e.ToString());
    });
}

问题是请求永远不会回来！成功/错误事件根本不会触发，并且请求似乎正在进入虚空。

有没有人有任何想法？

Answer 1

MessageBox.Show可能是问题的原因。我遇到了同样的问题，通过调试我发现ExecuteQueryAsync回调中的MessageBox.Show调用抛出异常“无效的跨线程访问”。我需要像这样包装调用才能使它工作：

Deployment.Current.Dispatcher.BeginInvoke(() => MessageBox.Show("Request Suceeded"));

Answer 2

试试这个： -

ClientContext clientContext = ClientContext.Current;
if (clientContext == null)
{
    SharepointUser = "[Unknown]";
}
else
{
            try
            {
    MessageBox.Show("Beginning server query now...");
    clientContext.Load(clientContext.Web, s => s.CurrentUser);
    clientContext.ExecuteQueryAsync((s, e) =>
    {
        MessageBox.Show("RESPONSE!");
        SharepointUser = clientContext.Web.CurrentUser.LoginName;
        MessageBox.Show("Hello, " + SharepointUser + "!");
    },
    (s, e) =>
    {
        MessageBox.Show("An error occurred: " + e.ToString());
    });
            }
            catch (Exception err)
            {
                 MessageBox.Show("Synchronous error occurred: " + err.ToString());
            }
}

如果尝试启动异步操作失败，则通常会同步抛出错误，而不是将其留给异步回调。

Sharepoint的clientContext.ExecuteQueryAsync（）没有回来

2 个答案: