(转帖) RichTextBox 实现查找字符串

private void button1_Click(object sender, EventArgs e)
        {
            string find = this.textBox1.Text;
            int index = this.richTextBox1.Find(find);
            if (index < 0)
            {
                MessageBox.Show("查找不到要搜索的字符串");
                return;
            }
            this.richTextBox1.SelectionStart = index;
            this.richTextBox1.SelectionLength = find.Length;
            this.richTextBox1.Focus();
        }