namespace _
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string yuan = textBox1.Text;
            string cha = textBox2.Text;
            int n=0;
            for (int i = 0; i < yuan.Length; i++)
            {
                n = yuan.IndexOf(cha, i);
                i += n;
            }
          textBox1.SelectionStart=n;
          textBox1.SelectionLength = yuan.Length;

        }
    }
}
请问我这样为什么不能选中texebox1要查找的字串，还有这样做正不正确...因为我做出来的效果是选不中要查找的字串的？？？

你谁？？？

不用这么麻烦吧...简化一点可以哦...