文件打开与读入

openFileDialog1.Filter = "文本文件(*.txt)|*.txt";//设置过滤参数
            openFileDialog1.ShowDialog();//显示打开文件的对话框
            textBox1.Text = openFileDialog1.FileName;
            StreamReader sr = new StreamReader(textBox1.Text, Encoding.Default);
            textBox2.Text = sr.ReadLine();
            sr.Close();