How to save Bitmap as icon? [duplicate]

Answer 1

a working sample using the name space System.IO can be like this

[System.Runtime.InteropServices.DllImport("user32.dll")]
extern static bool DestroyIcon(IntPtr handle);

private void buttonConvert2Ico_Click(object sender, EventArgs e)
{
    OpenFileDialog openFileDialog1 = new OpenFileDialog 

    openFileDialog1.InitialDirectory = "C:\\Data\\";
    openFileDialog1.Filter = "BitMap(*.bmp)|*.bmp";
    openFileDialog1.FilterIndex = 2;
    openFileDialog1.RestoreDirectory = true;

    if(openFileDialog1.ShowDialog() == DialogResult.OK)
    {
        try
        {
            string sFn = openFileDialog1.FileName;
            MessageBox.Show("Filename=" + sFn);
            string destFileName = sFn.Substring(0, sFn.Length -3) +"ico";

            // Create a Bitmap object from an image file.
            Bitmap bmp = new Bitmap(sFn);

            // Get an Hicon for myBitmap. 
            IntPtr Hicon = bmp.GetHicon();

            // Create a new icon from the handle. 
            Icon newIcon = Icon.FromHandle(Hicon);

            //Write Icon to File Stream
            System.IO.FileStream fs = new System.IO.FileStream(destFileName, System.IO.FileMode.OpenOrCreate);
            newIcon.Save(fs);
            fs.Close();
            DestroyIcon(Hicon);

            //DestroyIcon( hIcon);
            setStatus("Created icon From=" + sFn + ", into " + destFileName);
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error: Could not read/write file. Original error: " + ex.Message);
        }
    }
}