Windows Forms FAQ resources

20. Windows Forms ListBox

You can iterate through the list to find the longest text extent using MeasureString, adding a fudge factor if the is present.

System.Drawing.Graphics g = listBox1.CreateGraphics();

float maxWidth = 0f;

float height = 0f;

for(int i = 0; i < listBox1.Items.Count; ++i)

{

float w = g.MeasureString(listBox1.Items[i].ToString(), listBox1.Font).Width;

if(w > maxWidth)

maxWidth = w;

height += listBox1.GetItemHeight(i);

}

g.Dispose();

listBox1.Width = (int) (maxWidth + 6 + ((height > listBox1.Height - 4) ? 16 : 0)); // 16 is scrollbar width