幫助超出范圍的函數（C＃）

Question

我試圖調用CancelAsync ，雖然webClient超出范圍。

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


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

有人可以告訴我如何從這個事件處理程序調用webClient.CancelAsync()

Answer 1

您需要將WebClient存儲在類中的字段中。

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();
    }