private void Form1_Load(object sender, EventArgs e)
{
   _btnAddImage = new Button();
   _btnAddImage.Text = "Add Image";
   _btnAddImage.Click += AddPictureDialog;
   this.Controls.Add(_btnAddImage);
            
   _btnAddImage.Location = new Point(10, 10);
            
   c1Editor1.DocumentChanged += UpdateUI;
   c1Editor1.SelectionChanged += UpdateUI;
   c1Editor1.ModeChanged += UpdateUI;
}
            
private void AddPictureDialog(object sender, EventArgs e)
{
   c1Editor1.ShowDialog(DialogType.Image);
}
            
private void UpdateUI(object sender, EventArgs e)
{
   _btnAddImage.Enabled = c1Editor1.CanShowDialog(DialogType.Image);
}