webView2 uninitalize exception on navigate

Question

drag and drop WebView2 into a panel in winform as webView
here is my code

if (webView.CoreWebView2 == null) webviewInit();
webView.CoreWebView2.NavigateToString("https://finance.yahoo.com/quote/" + symbolTbx.Text); // this gets uninitialized exception during runtime.
...
async void webViewInit()

{
webView.Source = new Uri("https://finance.yahoo.com/quote/");
string userDataFolder = null;
CoreWebView2EnvironmentOptions options = null;
CoreWebView2Environment env = CoreWebView2Environment.CreateAsync("", userDataFolder, options).GetAwaiter().GetResult();
await webView.EnsureCoreWebView2Async(env);
}

what should I do?

Answer 1

You must initialize it, either with Source as the doc says at Get started with WebView2 in WinForms apps
or
with EnsureCoreWebView2Async, like :

        private async void Form1_LoadAsync(object sender, EventArgs e)  
        {  
            webView21.CoreWebView2InitializationCompleted += new System.EventHandler<Microsoft.Web.WebView2.Core.CoreWebView2InitializationCompletedEventArgs>(webView21_CoreWebView2InitializationCompleted);  
            await InitializeAsync();             
        }  

with

        private async Task InitializeAsync()  
        {  
            await webView21.EnsureCoreWebView2Async(null);  
        }  

test URL :

        private void webView21_CoreWebView2InitializationCompleted(object sender, Microsoft.Web.WebView2.Core.CoreWebView2InitializationCompletedEventArgs e)  
        {  
            if (webView21 != null && webView21.CoreWebView2 != null)  
            {                 
                webView21.CoreWebView2.Navigate("https://www.microsoft.com");  
            }             
        }