C#写的文件读写

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace 文件读写TXT
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {

            if (richTextBox1.Text == "")
            {

                MessageBox.Show("您没有，输入任何文字，无意义！");
            }

            else
            {
              
                if (openFileDialog1.ShowDialog() == DialogResult.OK)
                {


                    //类型为追加写入
                    StreamWriter sw = File.AppendText(openFileDialog1.FileName);
                    //开始写入   
                    textBox1.Text = openFileDialog1.FileName;
                    textBox2.Text = System.IO.Path.GetFileName(textBox1.Text);
                    sw.WriteLine(richTextBox1.Text, System.Environment.NewLine, Encoding.GetEncoding("gb2312"));
                    //清空缓冲区
                    sw.Flush();
                    sw.Close();
                    MessageBox.Show("文件写入成功！");
                    richTextBox1.Clear();
                    //关闭流           
                }
            }


        }   

        private void button1_Click_1(object sender, EventArgs e)
        {


            openFileDialog1.Filter = "文本文件(*.txt)|*.txt";
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                textBox1.Text = openFileDialog1.FileName;
                //如果打开对话框打开了
                StreamReader r = new StreamReader(openFileDialog1.FileName, Encoding.GetEncoding("gb2312"));
                //实例化StreamReader对象
                richTextBox1.Text = r.ReadToEnd();

                textBox1.Text = openFileDialog1.FileName;
                textBox2.Text = System.IO.Path.GetFileName(textBox1.Text);
                //使用ReadToEnd表示从当前位置一直读到末尾
                r.Close();
                //关闭读取流
            }


        }
    }
}