// save_file_dialog
private void button2_Click(object sender, EventArgs e)
{
if (saveFileDialog1.ShowDialog() == DialogResult.Cancel)
{
return;
}
string filename = saveFileDialog1.FileName;
string text = "";
if (figure != null)
{
text = figure.save_obj();
}
System.IO.File.WriteAllText(filename, text);
}