winfrom文本文档打开

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;//导入命名空间

namespace WindowsFormsApplication4
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void statusStrip1_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {

        }

        private void 查找ToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void 剪切TToolStripMenuItem_Click(object sender, EventArgs e)
        {
            textBox1.Cut();
        }

        private void 复制CToolStripMenuItem_Click(object sender, EventArgs e)
        {
            textBox1.Copy();
        }

        private void 粘贴PToolStripMenuItem_Click(object sender, EventArgs e)
        {
            textBox1.Paste();
        }

        private void 全选AToolStripMenuItem_Click(object sender, EventArgs e)
        {
            textBox1.SelectAll();
        }

        private void 撤消UToolStripMenuItem_Click(object sender, EventArgs e)
        {
            textBox1.Undo();
        }

        private void 打开OToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //创建打开文件对话框：实现硬盘上查找文件路径
           // OpenFileDialog openfiledialong1=new OpenFileDialog();//创建对象
            //可以在界面上造一个openfiledialog对象F大写
            openFileDialog1.Filter = "文本文档|*.txt|所有文件|*.*";//过滤
            DialogResult isok = openFileDialog1.ShowDialog();  //显示对话框  枚举类型的返回值
            if (isok == DialogResult.OK)//来通过对话框的返回值判断是否点的打开
            { 
                //获取文件路径
                string filename = openFileDialog1.FileName;
                //根据文件路径读取文件：使用流来读取   流：专门用于内盘跟英寸去交互、读写的
                //FileStream fs = new FileStream(filename,FileMode.Open );
                //StreamReader sr = new StreamReader(fs,Encoding.Default);//流读取器
                StreamReader sr = new StreamReader(filename, Encoding.Default);
                string text = sr.ReadToEnd();//读取
                sr.Close();
               // fs.Close();

                textBox1.Text = text;
            }
        }
    }
}