c# .net stop async method from running

Question

I am working on signalR. I have a server (ASP .NET) and a client (C# WinForms). In my client app I have a async method:

public async void conAsync()
{
    HubConn = new HubConnection(serverURL);
    HubPrx = HubConn.CreateHubProxy("myHUB");

    try
    {
        await HubConn.Start();
        richTextBox1.AppendText("connected");
        button1.BackColor = Color.Green;

        groupBox1.Enabled = true;
        groupBox2.Enabled = true;        
    }
    catch(Exception err)
    {
        // deactive comps
        groupBox1.Enabled = false;
        groupBox2.Enabled = false;        

        richTextBox1.AppendText(err.toString());
    }
}

The Start Button executes the above method. I want provide a Stop Button which stops the connection to the server. I read about CancellationToken but I got confused about how to use it in my case. Actually my button is a CheckBox which acts like a ToggleButton .

private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
    if (checkBox1.Checked)
    {
        checkBox1.ForeColor = Color.Green;
        conAsync();
    }
    else
    {
        //stop conAsync() here
    }
}

Answer 1

HubConn.close() 解决了这个问题，它停止了 conAsync() ..... 我认为取消令牌不是这里的解决方案（我错了）但它可能是另一种情况的替代方案。