小编cho*_*mba的帖子

protected void ListBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    //int test = Convert.ToInt32(ListBox1.SelectedValue.ToString());            
    //GetById(test);
    foreach (ListItem listitem in ListBox1.Items)
    {
        if (listitem.Selected == true)
        {
            string email = listitem.Text;
            GetByEmail(email);
        }
    }
}

这个方法应该选择item.I不是为什么,但它告诉我selected所有项目的属性都是false.

protected void Page_Load(object sender, EventArgs e)
{ 
    ListBox1.Items.Clear();
    SelectAllUsers();
}

public void SelectAllUsers()
{
    SchoolService.SchoolServiceClient client = new SchoolService.SchoolServiceClient();
    SchoolService.User[] userArray = client.SelectAll(0);

    int i = 0;

    while (i < userArray.Length)
    {                                
        ListItem listItem = new ListItem();
        listItem.Text = userArray[i].Email;
        listItem.Value = userArray[i].Id.ToString();                                      
        ListBox1.Items.Add(listItem);                
        i++;
    } …

在此示例代码中,代码以同步方式运行.为什么任务阻止DoIndependentWork()而不是仅阻止webTask.Result？我知道我可以使用Task.Run()和其他东西,但我正在尝试理解异步并等待更好一点.

static void Main(string[] args)
{
    var webTask = AccessTheWebAsync();
    DoIndependentWork();
    Console.WriteLine("AccessTheWebAsync result: {0}", webTask.Result);

    Console.ReadLine();
}

static async Task<int> AccessTheWebAsync()
{
    HttpClient client = new HttpClient();

    Thread.Sleep(5000);

    Console.WriteLine("AccessTheWebAsync in Thread {0}", Thread.CurrentThread.ManagedThreadId);

    var urlContents = await client.GetStringAsync("http://msdn.microsoft.com");

    return urlContents.Length;
}

static void DoIndependentWork()
{
    Console.WriteLine("DoIndependentWork in Thread {0}", Thread.CurrentThread.ManagedThreadId);
}