c# 打开文件

        //装载文件
       private void button4_Click(object sender, EventArgs e)
       {
           OpenFileDialog openFileDialog = new OpenFileDialog();
           openFileDialog.InitialDirectory = "c:\\";
           openFileDialog.Filter = "文本文件|*.*|C#文件|*.cs|所有文件|*.*";
           openFileDialog.RestoreDirectory = true;
           openFileDialog.FilterIndex = 1;
           if (openFileDialog.ShowDialog() == DialogResult.OK)
           {
   
           }
       }