Question

I’m new to programming in C#, and im looking for a quick solution. I have 2 buttons on form, one is calling the DownloadFileAsync(), and the second one should cancel this operation.
Code of first button:

private void button1_Click(object sender, EventArgs e)
{
...
WebClient webClient = new WebClient();
webClient.DownloadFileAsync(new Uri(textBox1.Text), destination);
}

Code of second button:

private void button2_Click(object sender, EventArgs e)
{
webClient.CancelAsync(); // yes, sure, WebClient is not known here.
}

Im looking for an idea how to solve this problem quickly (use the webClient from first function, in block of second).

Answer 1

That isn’t a private variable. webClient goes out of scope. You will have to make it a member variable of the class.

class SomeClass {
    WebClient webClient = new WebClient();

    private void button1_Click(object sender, EventArgs e)
    {
        ...
        webClient.DownloadFileAsync(new Uri(textBox1.Text), destination);
    }
}