ExtendedCheckBox

It is a CheckBox in every other way: CheckBox.Checked, CheckBox.CheckState, CheckBox.ThreeState, the CheckBox.CheckedChanged event, the keyboard and the accessibility all work as usual. Only the picture changes.

Colours

• NormalControlColor draws the box and the tick, black by default.
• OnFocusControlColor takes over while the pointer is over the control or it has the keyboard focus, the system highlight colour by default – so the control answers the pointer.
• ControlBackColor fills the inside of the box, the window colour by default.
• The control's own Control.BackColor fills the area round the box and the text, and Control.ForeColor colours the text.

A disabled check box is drawn with a grey box on the system control colour and grey text.

Size and layout

The box grows with the font (to about four fifths of the font's height, and never below 11 logical pixels), and stays sharp at any display scale because it is drawn, not copied from an image. CheckBox.CheckAlign, TextAlign, Control.Padding and Control.RightToLeft place the box and the text as on a standard check box.

An indeterminate check box (Indeterminate) is drawn with the same tick as a checked one.

Two options on an export dialog, in the application's brand colours.

using System;
using System.Drawing;
using System.Windows.Forms;
using Binarymission.WinForms.Controls.ButtonControls;

public class ExportOptionsForm : Form
{
    private readonly ExtendedCheckBox _includeInvoices = new ExtendedCheckBox();
    private readonly ExtendedCheckBox _zipFiles = new ExtendedCheckBox();

    public ExportOptionsForm()
    {
        Text = "Export orders";

        _includeInvoices.Text = "Include invoices (PDF)";
        _includeInvoices.Location = new Point(16, 16);
        _includeInvoices.AutoSize = true;
        _includeInvoices.Checked = true;
        _includeInvoices.NormalControlColor = Color.FromArgb(0, 84, 147);
        _includeInvoices.OnFocusControlColor = Color.FromArgb(0, 120, 212);
        _includeInvoices.ControlBackColor = Color.AliceBlue;

        _zipFiles.Text = "Compress into a single .zip file";
        _zipFiles.Location = new Point(16, 44);
        _zipFiles.AutoSize = true;
        _zipFiles.NormalControlColor = Color.FromArgb(0, 84, 147);
        _zipFiles.OnFocusControlColor = Color.FromArgb(0, 120, 212);
        _zipFiles.CheckedChanged += (sender, e) => Console.WriteLine("Zip: " + _zipFiles.Checked);

        Controls.Add(_includeInvoices);
        Controls.Add(_zipFiles);
    }
}