如何找到文件的家-打开文件对话框openFileDialog

private void button1_Click(object sender, EventArgs e)
        {
            openFileDialog1.Filter = "*.txt|*.txt";//设置文件
            DialogResult dr = openFileDialog1.ShowDialog();//显示打开文件对话框
            if (dr ==DialogResult.OK)
            {
                richTextBox1.Text = System.IO.File.ReadAllText(openFileDialog1.FileName, Encoding.Default);
            }
        }运行结果如图所示：