string text; Select select; Stack analyse; Stack input; public Liststring result_analys; public Liststring result_input; public Liststring result_parse;

补全代码：

private void button7_Click(object sender, EventArgs e) { listView4.Clear(); listView4.Columns.Add("步骤", 100, HorizontalAlignment.Center); listView4.Columns.Add("分析串", 150, HorizontalAlignment.Center); listView4.Columns.Add("剩余输入串", 150, HorizontalAlignment.Center); listView4.Columns.Add("推导所用产生式", 200, HorizontalAlignment.Center);

string text = richTextBox2.Text;
analyse_sentence analyse = new analyse_sentence(text, new Select(selects));
for (int i = 0; i < analyse.result_analys.Count; i++)
{
    ListViewItem item = new ListViewItem(new string[] { (i + 1).ToString(), analyse.result_analys[i], analyse.result_input[i], analyse.result_parse[i] });
    listView4.Items.Add(item);
}

}

private void button8_Click(object sender, EventArgs e) { listView4.Clear(); listView4.Columns.Add("步骤", 100, HorizontalAlignment.Center); listView4.Columns.Add("分析串", 150, HorizontalAlignment.Center); listView4.Columns.Add("剩余输入串", 150, HorizontalAlignment.Center); listView4.Columns.Add("推导所用产生式", 200, HorizontalAlignment.Center);

string text = richTextBox2.Text;
analyse_sentence analyse = new analyse_sentence(text, new Select(selects));
for (int i = 0; i < analyse.result_analys.Count; i++)
{
    ListViewItem item = new ListViewItem(new string[] { (i + 1).ToString(), analyse.result_analys[i], analyse.result_input[i], analyse.result_parse[i] });
    listView4.Items.Add(item);
    System.Threading.Thread.Sleep(500);
}

}

private void button9_Click(object sender, EventArgs e) { listView4.Clear(); listView4.Columns.Add("步骤", 100, HorizontalAlignment.Center); listView4.Columns.Add("分析串", 150, HorizontalAlignment.Center); listView4.Columns.Add("剩余输入串", 150, HorizontalAlignment.Center); listView4.Columns.Add("推导所用产生式", 200, HorizontalAlignment.Center);

string text = richTextBox2.Text;
analyse_sentence analyse = new analyse_sentence(text, new Select(selects));
for (int i = 0; i < analyse.result_analys.Count; i++)
{
    ListViewItem item = new ListViewItem(new string[] { (i + 1).ToString(), analyse.result_analys[i], analyse.result_input[i], analyse.result_parse[i] });
    listView4.Items.Add(item);
}