AutoSized, Wrapping RadioButton and CheckBox (C#)

Article
11/14/2005

The following RadioButton and CheckBox will text-wrap when placed in a TableLayoutPanel or FlowLayoutPanel.

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

namespace WrappingControlSample {
/// <summary>
/// A check box that can wrap its text onto multiple lines as needed.
/// </summary>
public class WrappingCheckBox : System.Windows.Forms.CheckBox {
System.Drawing.Size cachedSizeOfOneLineOfText = System.Drawing.Size.Empty;
Dictionary<Size, Size> preferredSizeHash = new Dictionary<Size, Size>(3); // typically we've got three different constraints.

public WrappingCheckBox() {
this.AutoSize = true;
}

protected override void OnTextChanged(EventArgs e) {
base.OnTextChanged(e);
CacheTextSize();
}

protected override void OnFontChanged(EventArgs e) {
base.OnFontChanged(e);
CacheTextSize();
}

private void CacheTextSize() {
//When the text has changed, the preferredSizeHash is invalid...
preferredSizeHash.Clear();

if (String.IsNullOrEmpty(this.Text)) {
cachedSizeOfOneLineOfText = System.Drawing.Size.Empty;
}
else {
cachedSizeOfOneLineOfText = TextRenderer.MeasureText(this.Text, this.Font, new Size(Int32.MaxValue, Int32.MaxValue), TextFormatFlags.WordBreak);
}
}

public override Size GetPreferredSize(Size proposedSize) {
Size prefSize = base.GetPreferredSize(proposedSize);
if ((prefSize.Width > proposedSize.Width) && (!String.IsNullOrEmpty(this.Text) && !proposedSize.Width.Equals(Int32.MaxValue) || !proposedSize.Height.Equals(Int32.MaxValue))) {
// we have the possiblility of wrapping... back out the single line of text
Size bordersAndPadding = prefSize - cachedSizeOfOneLineOfText;
// add back in the text size, subtract baseprefsize.width and 3 from proposed size width so they wrap properly
Size newConstraints = proposedSize - bordersAndPadding - new Size(3, 0);
if (!preferredSizeHash.ContainsKey(newConstraints)) {
prefSize = bordersAndPadding + TextRenderer.MeasureText(this.Text, this.Font, newConstraints, TextFormatFlags.WordBreak);
preferredSizeHash[newConstraints] = prefSize;
}
else {
prefSize = preferredSizeHash[newConstraints];
}
}
return prefSize;
}
}

public class WrappingRadioButton : System.Windows.Forms.RadioButton {
System.Drawing.Size cachedSizeOfOneLineOfText = System.Drawing.Size.Empty;
Dictionary<Size, Size> preferredSizeHash = new Dictionary<Size, Size>(3); // typically we've got three different constraints.

public WrappingRadioButton() {
this.AutoSize = true;
}

protected override void OnTextChanged(EventArgs e) {
base.OnTextChanged(e);
CacheTextSize();
}

protected override void OnFontChanged(EventArgs e) {
base.OnFontChanged(e);
CacheTextSize();
}

private void CacheTextSize() {
//When the text has changed, the preferredSizeHash is invalid...
preferredSizeHash.Clear();

}

AutoSized, Wrapping RadioButton and CheckBox (C#)

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