public class ToggleButton : System.Windows.Forms.CheckBox
{
// This class subclasses a CheckBox to combine the benefits of a Checkbox and
// Checkbox-with-Button-Appearance by combining a checkbox and button into one control.
//
// Requirements:
// [1] Two states (like a checkbox).
// [2] Visually imply action/control (like a button).
// I think a Checkbox fails this requirement.
// [3] It should be intuitively obvious what the state is and what the button will do when clicked.
// A checkbox meets the state requirement but fails the Action requirement because
// checkboxes are typically used for configuration rather than action.
// I think a Checkbox-with-button-appearance fails because it's not obvious if the button is depressed or not.
// I think a button-with-changing-text fails. Does the text show state or the on-click (oposite) action?
// Designers use button-with-changing-text inconsistently.
// [4] Explicity show State even with poor dispplay visibility.
// I think a Checkbox-with-button-appearance fails this requirement.
// [5] Works on all resolutions and themes, doesn't look to 'flashy' and must 'fit-in'
// I think a 2-bitmapped button would fail this requirement.
// Many 3-rd party buttons fail this requirement.
//
// This class uses DrawToBitmap to capture a temporary Checkbox's appearance.
// It captures just the checkbox without the text.
// I want to use a standard checkbox to be consistent with system-wide styles.
//
// Design usage:
// [1] Add this class ToggleButton to project.
// [2] Add 'normal' checkbox to WinForm
// [3] Change it's class to this ToggleButton class (in both the declaration and instantiation).
// [4] Set properties...
// Appearance = System.Windows.Forms.Appearance.Button;
// TextImageRelation = System.Windows.Forms.TextImageRelation.ImageBeforeText;
//
// Room for improvement:
// There's probably a way to automatically change Image based on state. I don't know yet.
// Create a user control that's more portable (although it's easy to add a class to a project).
// Consider making the bitmaps static merely to save space.
System.Drawing.Bitmap bmChecked;
System.Drawing.Bitmap bmUnChecked;
//constructor
public ToggleButton() : base()
{
System.Windows.Forms.CheckBox chkTemp = new System.Windows.Forms.CheckBox(); // Temporary checkbox with no text.
chkTemp.AutoSize = true;
chkTemp.BackColor = System.Drawing.Color.Transparent;
chkTemp.Size = new System.Drawing.Size(15, 14);
chkTemp.UseVisualStyleBackColor = false;
bmChecked = new System.Drawing.Bitmap(chkTemp.Width, chkTemp.Height);
bmUnChecked = new System.Drawing.Bitmap(chkTemp.Width, chkTemp.Height);
// Set checkbox false and capture bitmap.
chkTemp.Checked = false;
chkTemp.DrawToBitmap(bmUnChecked, new System.Drawing.Rectangle(0, 0, chkTemp.Width, chkTemp.Height));
// Set checkbox true and capture bitmap.
chkTemp.Checked = true;
chkTemp.DrawToBitmap(bmChecked, new System.Drawing.Rectangle(0, 0, chkTemp.Width, chkTemp.Height));
this.CheckedChanged += new System.EventHandler(this.btnToggleButton_CheckedChanged);
this.Image = this.Checked ? bmChecked : bmUnChecked;
}
// Change the this.Image
private void btnToggleButton_CheckedChanged(object sender, System.EventArgs e)
{
this.Image = this.Checked ? bmChecked : bmUnChecked;
}
}