Winform ListBox DrawItem

Question

本帖最后由 gaohaili4330508 于 2011-06-23 11:26:38 编辑

Answer 1

private void Form1_Load(object sender, EventArgs e)
        {
            listBox1.DrawMode = DrawMode.OwnerDrawFixed;
            listBox1.Items.Add("News today");
            listBox1.Items.Add("News yesterday");
        }          private void button1_Click(object sender, EventArgs e)
        {
            listBox1.Refresh();
        }        private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            //
            // Draw the background of the ListBox control for each item.            e.DrawBackground();            string keyWords = textBox1.Text;            string text = ((ListBox)sender).Items[e.Index].ToString();            List<int> keyWordIndexes = new List<int>();            //Keywords match
            if (!string.IsNullOrEmpty(keyWords))
            {
                int index = 0;
                while (index >= 0)
                {
                    index = text.IndexOf(keyWords, index);                    if (index >= 0)
                    {
                        keyWordIndexes.Add(index);
                        index += keyWords.Length;
                    }
                }
            }            //If no keywords matched show black color
            if (keyWordIndexes.Count == 0)
            {
                e.Graphics.DrawString(text, e.Font, Brushes.Black, 
                    e.Bounds, StringFormat.GenericDefault);
                e.DrawFocusRectangle();
                return;
            }            //Draw
            //Keywords red color            int start = 0;
            float x = 0;
            float y = e.Bounds.Y;            foreach (int i in keyWordIndexes)
            {
                string normal = text.Substring(start, i - start);                e.Graphics.DrawString(normal, e.Font, Brushes.Black,
                    x, y);
                
                x += e.Graphics.MeasureString(normal, e.Font).Width;                string key = text.Substring(i, keyWords.Length);                e.Graphics.DrawString(key, e.Font, Brushes.Red,
                    x, y);                x += e.Graphics.MeasureString(key, e.Font).Width;                start = i + keyWords.Length;
            }            if (start < text.Length)
            {
                string normal = text.Substring(start, text.Length - start);                e.Graphics.DrawString(normal, e.Font, Brushes.Black,
                    x, y);            }            e.DrawFocusRectangle();        }