C# winform中OpenFileDialog的运用还可以多选

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.OleDb;
using System.Runtime.InteropServices;
using System.IO;

private void button4_Click(object sender, System.EventArgs e)
{
Stream mystream;
OpenFileDialog openfiledialog1=new OpenFileDialog();
openfiledialog1.Multiselect=true;//允许同时选择多个文件
openfiledialog1.InitialDirectory="c:\\";
openfiledialog1.Filter="txt files(*.txt)|*.txt|All files(*.*)|*.*";
openfiledialog1.FilterIndex=2;
openfiledialog1.RestoreDirectory=true;
if(openfiledialog1.ShowDialog()==DialogResult.OK)
{
if((mystream=openfiledialog1.OpenFile())!=null)
{
this.textBox2.Text="";
for(int fi=0;fi<openfiledialog1.FileNames.Length;fi++)
{
this.textBox2.Text+=openfiledialog1.FileNames[fi].ToString();
}
mystream.Close();
}
}
}