Question

Error 1 The base class or interface 'System.ComponentModel.Component' in assembly 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' referenced by type 'System.Windows.Forms.Timer' could not be resolved

k:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Windows.Forms.dll App2

I got this error message after adding system.windows.forms reference.

Answer 1

Since you are using Wpf I made quick working example. Make sure your project references look like this.

MainWindow

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Forms;

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        Timer tmr = new Timer();
        public MainWindow()
        {
            InitializeComponent();
            tmr.Interval = 2000;
            tmr.Tick += new EventHandler(tmr_Tick);
            tmr.Start();
        }

        void tmr_Tick(object sender, EventArgs e)
        {
            tmr.Stop();
            throw new NotImplementedException();
        }
    }
}

---

And as roken stated it would be easier if you could use the Wpf Dispatcher Timer. IN looking at the example link there is no pressing need to be using a Windows Form Timer, the Dispatcher timer will work fine in this case since this is a WPF program.

Edit Modified based on your link

public partial class MainWindow : Window
{
    System.Windows.Threading.DispatcherTimer tmrStart = new System.Windows.Threading.DispatcherTimer();
    System.Windows.Threading.DispatcherTimer tmrStop = new System.Windows.Threading.DispatcherTimer();
    public MainWindow()
    {
        InitializeComponent();
        tmrStart.Interval = TimeSpan.FromSeconds(2); //Delay before shown
        tmrStop.Interval = TimeSpan.FromSeconds(3);  //Delay after shown
        tmrStart.Tick += new EventHandler(tmr_Tick);
        tmrStop.Tick += new EventHandler(tmrStop_Tick);

    }

    void tmrStop_Tick(object sender, EventArgs e)
    {
        tmrStop.Stop();
        label1.Content = "";
    }

    void tmr_Tick(object sender, EventArgs e)
    {
        tmrStart.Stop();
        label1.Content = "Success";
        tmrStop.Start();
    }

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        tmrStart.Start();
    }


}