Question

    private void button7_Click(object sender, RoutedEventArgs e)
    {
        WebClient client = new WebClient();
        client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
        client.DownloadStringAsync(new Uri("http://asd.com/bb"));
    }

    void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
    {
        if (e.Error == null)
        {
            MessageBox.Show(e.Result);

        }
        else {
            MessageBox.Show("err: " + e.Error.ToString());
        }
    }

how can i get the url from DownloadStringCompleted? Or how Can i pass some parameter to my DownloadStringCompleted?

Help please

Answer 1

You can pass any object through the second parameter of DownloadStringAsync. Then you can retrieve that object through DownloadStringCompletedEventArgs.UserState.

private void button7_Click(object sender, RoutedEventArgs e)
{
    WebClient client = new WebClient();
    client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
    var uri = new Uri("http://asd.com/bb");
    client.DownloadStringAsync(uri, uri);
}

void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
    var uri = e.UserState as Uri;
    //...
}