帮助超出范围的函数（C＃）

Question

I am trying to call CancelAsync , although webClient is out of scope.

private void Download_Click(object sender, EventArgs e)
{
    WebClient webClient = new WebClient();
}


private void Button1_Click(object sender, EventArgs e)
{
    webClient.CancelAsync();
}

Could someone show me how webClient.CancelAsync() could be called from this event handler please

Answer 1

您需要将WebClient存储在类中的字段中。

Answer 2

class ....
{
    WebClient webClient;

    private void Download_Click(object sender, EventArgs e)
    {
        webClient = new WebClient();
    }


    private void Button1_Click(object sender, EventArgs e)
    {
        webClient.CancelAsync();
    }