Need help creating a custom ListBox in C# WinForms (Visual Studio 2022) [closed]

Set the DrawMode to OwnerDrawFixed and override OnDrawItem where you put your drawing logic.

Here is an example of a ListBox displaying font names along with a font example:

public class FontFamilyListBox : ListBox { public FontFamilyListBox() { IntegralHeight = false; SelectionMode = SelectionMode.One; ItemHeight = Math.Max(ItemHeight, 18); Height = 16 * ItemHeight + 3; DrawMode = DrawMode.OwnerDrawFixed; foreach (var family in FontFamily.Families) { Items.Add(family.Name); } } protected override void OnDrawItem(DrawItemEventArgs e) { const string ExampleText = "Abc 123"; string fontFamilyName = (string)Items[e.Index]; using var itemFont = new Font(fontFamilyName, 12); using var brush = new SolidBrush(e.ForeColor); e.DrawBackground(); e.Graphics.DrawString(itemFont.Name, Font, brush, e.Bounds.X, e.Bounds.Y); float textWidth = e.Graphics.MeasureString(itemFont.Name, Font).Width; float exampleWidth = e.Graphics.MeasureString(ExampleText, itemFont).Width; if (textWidth + exampleWidth + 3 < e.Bounds.Width) { e.Graphics.DrawString(ExampleText, itemFont, brush, e.Bounds.Right - exampleWidth - 1, e.Bounds.Y); } e.DrawFocusRectangle(); } }

You can find the original code on my GitHub