任务完成后处理代码

Question

我试图在异步任务执行时显示一个等待符号。

我

对此真的很陌生，所以如果有更好的方法来实现这段代码，请启发我:)

但是，除了代码完成后隐藏 pictureBox1 并且现在找到结果之外，一切都可以正常工作。换句话说，当有结果时，图片框1被隐藏

以下是每次打开 Outlook 项目时运行的方法

private void FormRegion1_FormRegionShowing(object sender, System.EventArgs e)
    {   
            if (this.OutlookItem is Microsoft.Office.Interop.Outlook.MailItem)
            {
                Microsoft.Office.Interop.Outlook.MailItem item = (Microsoft.Office.Interop.Outlook.MailItem)this.OutlookItem;
                getContactByEmail(item);                    
            }
    }

这是我实现等待的方法

public async Task getContactByEmail(Microsoft.Office.Interop.Outlook.MailItem item)
    {
        pictureBox1.Visible = true;
        using (var client = new System.Net.Http.HttpClient())
        {
            client.BaseAddress = new Uri("http://api.....");
            client.DefaultRequestHeaders.Accept.Clear();
            HttpResponseMessage response = await client.GetAsync("tools/getContactByEmail?email=" + item.SenderEmailAddress + "&key=1232");
            if (response.IsSuccessStatusCode)
            {
                SimpleContact contact = await response.Content.ReadAsAsync<SimpleContact>();
                lblName.Text = contact.Name;
                lblMobile.Text = contact.Phone;
            }
            pictureBox1.Visible = false;
        }
    }

Answer 1

发布解决此问题的代码，以便不会引发异常

if (response.IsSuccessStatusCode)
{
    SimpleContact contact = await response.Content.ReadAsAsync<SimpleContact>();
    if (contact != null)
    {
      lblName.Text = contact.Name;
      lblMobile.Text = contact.Phone;
    }
   pictureBox1.Visible = false;
}

Answer 2

在C#中，方法名称始终为驼峰，异步方法始终后缀为Async。只是约定。

您可能希望将非 UI 代码提取到另一个异步方法，以避免来回到 UI 线程：

private async void FormRegion1_FormRegionShowing(object sender, System.EventArgs e)
{   
        if (this.OutlookItem is Microsoft.Office.Interop.Outlook.MailItem)
        {
            Microsoft.Office.Interop.Outlook.MailItem item = (Microsoft.Office.Interop.Outlook.MailItem)this.OutlookItem;
            pictureBox1.Visible = true;
            var contact = GetContactByEmailAsync(item);
            if (contact != null)
            {
                lblName.Text = contact.Name;
                lblMobile.Text = contact.Phone;
            }
            pictureBox1.Visible = false;
        }
}
public async Task<SimpleContact> GetContactByEmailAsync(Microsoft.Office.Interop.Outlook.MailItem item)
{
    using (var client = new System.Net.Http.HttpClient())
    {
        client.BaseAddress = new Uri("http://api.....");
        client.DefaultRequestHeaders.Accept.Clear();
        HttpResponseMessage response = await client.GetAsync(
            "tools/getContactByEmail?email=" + item.SenderEmailAddress + "&key=1232")
            .ConfigureAwait(false);
        return (response.IsSuccessStatusCode)
            ? await response.Content.ReadAsAsync<SimpleContact>();
            : null;
    }
}

注意：不要忘记正确的异常处理!!