publicpartial class Form2 : Form         {             private string text;             private ListBox lb;             private int index;            //构造函数接收三个参数：选中行文本，ListBox控件，选中行索引             public Form2(string text,ListBox lb,int index)             {                 this.text = text;                 this.lb = lb;                 this.index = index;                 InitializeComponent();                 this.textBox1.Text = text;             }             private void btnChange_Click(object sender, EventArgs e)             {                            string text = this.textBox1.Text;                 this.lb.Items.RemoveAt(index);                 this.lb.Items.Insert(index, text);                 this.Close();             }         }

public partial class Form1 :Form         {             int index = 0;             string text = null;             public Form1()             {                 InitializeComponent();             }             private void listBox1_SelectedIndexChanged(object sender, EventArgse)             {                             if (this.listBox1.SelectedItem != null)                 {                     text = this.listBox1.SelectedItem.ToString();                     index = this.listBox1.SelectedIndex;                    //构造Form2同时传递参数                     Form2 form2 = new Form2(text, listBox1, index);                     form2.ShowDialog();                 }            }