.NET (Core and Framework)

private void btnProxyAuto_Click(object sender, EventArgs e)   
        {   
            WebClient.webUser myService = new coProxy.WebClient.webUser();   
            myService.Proxy = System.Net.WebRequest.DefaultWebProxy;   
            myService.Credentials = CredentialCache.DefaultCredentials;   
            //   
            try   
            {   
                DateTime dt = myService.SyncDB();   
                AddLinesTextbox("1. Webservice Auto Detect Proxy Connection success");   
                AddLinesTextbox("1. Server time: " + dt.ToLongDateString());   
            }   
            catch (Exception ex)   
            {   
  
                AddLinesTextbox("1. Webservice Auto Detect Proxy Connection failed");   
                AddLinesTextbox("1. " + ex.ToString());   
            }   
        }   
        //1   
        private void btnProxyAndCredentials_Click(object sender, EventArgs e)   
        {   
            if (!TestInput())   
            {   
                //    Testinput() is simple function to check if username and psw are filled in.
                AddLinesTextbox("2. Please fill in the username and password");   
                return;   
            }   
            if (tbProxyAddress.Text.Length == 0)   
            {   
                AddLinesTextbox("2. Please fill in the proxyserver address.");   
                return;   
            }   
            if (tbPort.Text.Length == 0)   
            {   
                AddLinesTextbox("2. Please fill in the proxy port.");   
                return;   
            }   
  
            int pPort = 80;   
            try{   
                pPort = Convert.ToInt32(tbPort.Text);   
            }   
            catch(Exception ex){   
                AddLinesTextbox("2. No valid port.");   
                AddLinesTextbox("2. " + ex.ToString());   
            }   
            //   
            System.Net.WebProxy proxyObject = new System.Net.WebProxy(tbProxyAddress.Text, pPort);   
            proxyObject.Credentials = new System.Net.NetworkCredential(tbUsername.Text, tbPassword.Text, tbProxyDomain.Text);   
            //   
            WebClient.webUser myService = new coProxy.WebClient.webUser();   
            myService.Proxy = proxyObject;   
  
            try   
            {   
                DateTime dt = myService.SyncDB();   
                //   
                AddLinesTextbox("2. Webservice Connection success ");   
                AddLinesTextbox("2. Server time: " + dt.ToLongDateString());   
            }   
            catch (Exception ex)   
            {   
                AddLinesTextbox("2. Webservice Connection failed");   
                AddLinesTextbox("2. " + ex.ToString());   
            }   
        }