CountdownEventクラスの少し変な使い方が広まってるっぽいので私の使い方を書いておく。
public class HogeForm : Form
//WebView2 wv2を持つフォーム
{
private readonly CountdownEvent countdownevent = new CountdownEvent(1);
//Dispose省略 忘れずに
private void wv2_NavigationCompleted(object sender,
Microsoft.Web.WebView2.Core.CoreWebView2NavigationCompletedEventArgs e)
{
if (!countdownevent.IsSet) { countdownevent.Signal(); }
}
public async Task LoadWebpageAsync(string url)
{
countdownevent.Reset();
wv2.Source = new Uri(url);
bool flg = await Task.Run