private void AddShapeButton_Click(object sender, EventArgs e) { if (ShapeTypeCombo.SelectedItem == null) { MessageBox.Show(@"Please select a shape to add", @"Shape Type Required", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } if (string.IsNullOrEmpty(ShapeWidth.Text)) { MessageBox.Show(@"Please enter a width", @"Width Required", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } if (!ShapeWidth.Text.All(char.IsDigit)) { MessageBox.Show(@"Please enter a numeric value for the width", @"Width Required", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } if (string.IsNullOrEmpty(ShapeHeight.Text)) { MessageBox.Show(@"Please enter a height", @"Height Required", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } var width = Convert.ToInt32(ShapeWidth.Text); var height = Convert.ToInt32(ShapeHeight.Text); if (width < 10 || width > 100) { MessageBox.Show(@"Please enter a width between 10 and 100", @"Width Incorrect", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } if (height < 10 || height > 100) { MessageBox.Show(@"Please enter a height between 10 and 100", @"Height Incorrect", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } Rectangle r = CreateShape(ShapeTypeCombo.SelectedItem.ToString(), width, height); Rectangles.Add(r); Canvas.Controls.Add(new Panel { BorderStyle = BorderStyle.FixedSingle, Width = r.GetWidth(), Height = r.GetHeight(), Left = r.Left, Top = r.Top, BackColor = Color.FromArgb(Random.Next(256), Random.Next(256), Random.Next(256)) }); }