C# 网络客户端重试

是否可以重试webclient请求？偶尔，我的应用程序在尝试连接到XMLWeb服务时会抛出错误，但如果我重试，它会正常工作。我希望在抛出错误之前重试2次，除非有人有更好的解决方案：）

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WebClient没有任何内置的重试功能

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您应该在通知用户问题之前自己构建重试逻辑。

如果失败，您可以重新发出请求。通过记录重新发出请求的次数，可以确定何时向用户显示错误。下面是对代码的快速修改，以演示我的意思

private void ApplicationBarLogin_Click(object sender, EventArgs e)
{
    settings.UsernameSetting = Username.Text;
    if (RememberPassword.IsChecked == true)
    {
        settings.PasswordSetting = Password.Password;
        settings.RememberPasswordSetting = true;
    }
    else
    {
        settings.RememberPasswordSetting = false;
    }

    WebClient internode = new WebClient();

    internode.Credentials = new NetworkCredential(settings.UsernameSetting, settings.PasswordSetting);
    internode.DownloadStringCompleted += new DownloadStringCompletedEventHandler(internode_DownloadStringCompleted);
    internode.DownloadStringAsync(new Uri("https://customer-webtools-api.internode.on.net/api/v1.5/"));
}

private int _retryCount = 0;

public void internode_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
    if (e.Error != null)
    {
        _retryCount++;
        if (_retryCount < 3)
        {
            WebClient internode = (WebClient)sender;
            internode.DownloadStringAsync(new Uri("https://customer-webtools-api.internode.on.net/api/v1.5/"));
        }
        else
        {
            _retryCount = 0;
            MessageBox.Show(e.Error.Message);
        }
    }
    else
    {
        _retryCount = 0;
        MessageBox.Show("Authentication successfull.");
    }
}

private void ApplicationBarLogin\u单击（对象发送者，事件参数e）
{
settings.usernameseting=Username.Text；
if（RememberPassword.IsChecked==true）
{
settings.PasswordSetting=Password.Password；
settings.RememberPasswordSetting=true；
}
其他的
{
settings.RememberPasswordSetting=false；
}
WebClient internode=新的WebClient（）；
internode.Credentials=newnetworkcredential（settings.usernameseting，settings.PasswordSetting）；
internode.DownloadStringCompleted+=新的DownloadStringCompletedEventHandler（internode_DownloadStringCompleted）；
internode.DownloadStringAsync（新Uri（“https://customer-webtools-api.internode.on.net/api/v1.5/"));
}
私有整数_retryCount=0；
public void internode_DownloadStringCompleted已完成（对象发送方，DownloadStringCompletedEventArgs e）
{
如果（例如错误！=null）
{
_retryCount++；
如果（_retryCount<3）
{
WebClient internode=（WebClient）发送方；
internode.DownloadStringAsync（新Uri（“https://customer-webtools-api.internode.on.net/api/v1.5/"));
}
其他的
{
_retryCount=0；
MessageBox.Show（例如Error.Message）；
}
}
其他的
{
_retryCount=0；
Show（“身份验证成功”）；
}
}

WebClient中的重试功能后，我不一定会退出。我如何完成重试逻辑以适应上面的代码？

private void ApplicationBarLogin_Click(object sender, EventArgs e)
{
    settings.UsernameSetting = Username.Text;
    if (RememberPassword.IsChecked == true)
    {
        settings.PasswordSetting = Password.Password;
        settings.RememberPasswordSetting = true;
    }
    else
    {
        settings.RememberPasswordSetting = false;
    }

    WebClient internode = new WebClient();

    internode.Credentials = new NetworkCredential(settings.UsernameSetting, settings.PasswordSetting);
    internode.DownloadStringCompleted += new DownloadStringCompletedEventHandler(internode_DownloadStringCompleted);
    internode.DownloadStringAsync(new Uri("https://customer-webtools-api.internode.on.net/api/v1.5/"));
}

private int _retryCount = 0;

public void internode_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
    if (e.Error != null)
    {
        _retryCount++;
        if (_retryCount < 3)
        {
            WebClient internode = (WebClient)sender;
            internode.DownloadStringAsync(new Uri("https://customer-webtools-api.internode.on.net/api/v1.5/"));
        }
        else
        {
            _retryCount = 0;
            MessageBox.Show(e.Error.Message);
        }
    }
    else
    {
        _retryCount = 0;
        MessageBox.Show("Authentication successfull.");
    }
}