先设置listBoxMsg.DrawMode = DrawMode.OwnerDrawFixed; 

private void listBoxMsg_DrawItem(object sender, DrawItemEventArgs e)         {

            ListBox lb= (ListBox)sender;

            string s = lb.Items[e.Index].ToString();

            if (s.Length * 15 > this.Width)

                this.Width = s.Length * 15;

            Brush myBrush = Brushes.Black;

            Image image=null;//绘制图标

            if (s.Contains("。"))

            {

                image = Image.FromFile(ResourceObj.DirectoryCurrent + "\\PIC\\Default\\error.png");

            }

            else

            {

                image = Image.FromFile(ResourceObj.DirectoryCurrent + "\\PIC\\Default\\excla.png");

            }

            //e.Graphics.FillRectangle(myBrush, e.Bounds);

            //e.DrawFocusRectangle();//焦点框

            Graphics g = e.Graphics;

            Rectangle bounds = e.Bounds;

            Rectangle imageRect = new Rectangle( bounds.X, bounds.Y-2, bounds.Height-4, bounds.Height-4);

            Rectangle textRect = new Rectangle( imageRect.Right, bounds.Y, bounds.Width - imageRect.Right, bounds.Height);

            if (image != null)

            {

                g.DrawImage(image,  imageRect,  0, 0,image.Width,image.Height, GraphicsUnit.Pixel);

            }

            //文本

            StringFormat strFormat = new StringFormat();

            strFormat.LineAlignment = StringAlignment.Near;

            e.Graphics.DrawString(listBoxMsg.Items[e.Index].ToString(), e.Font, new SolidBrush(Color.FromArgb(0, 0, 0)), textRect, strFormat);

        }