private void ShapeBox_SelectedIndexChanged(object sender, EventArgs e) { switch (ShapeBox.SelectedIndex) { case 0: //rectangle ClearContext(); RedTextBox.Select(); WidthLabel.Show(); HeightLabel.Show(); WidthTextBox_Rectangle.Show(); HeightTextBox_Rectangle.Show(); break; case 1: //square ClearContext(); RedTextBox.Select(); WidthLabel.Show(); WidthTextBox_Square.Show(); break; case 2: //circle ClearContext(); RedTextBox.Select(); RadiusLabel.Show(); RadiusTextBox_Circle.Show(); break; } }