C# 打开和保存文件对话框

保存文件

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 保存文件
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SaveFileDialog sfd = new SaveFileDialog();
            sfd.Title = "";
            sfd.InitialDirectory = @"C:\";
            sfd.Filter = "文本文件| *.txt";
            sfd.ShowDialog();

            string path = sfd.FileName;
            if (path == "")
            {
                return;
            }

            using (FileStream fsWrite = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write))
            {
                byte[] buffer = Encoding.Default.GetBytes(textBox1.Text);
                fsWrite.Write(buffer, 0, buffer.Length);
                MessageBox.Show("保存成功");

            }
        }
    }
}

打开文件

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 对话框
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Title="请选择要打开的文件";
            //多选
            ofd.Multiselect = true;
            //初始目录
            ofd.InitialDirectory = @"C:\";
            //设定文件类型
            ofd.Filter = "文本文件 | *.txt";
            ofd.ShowDialog();

            //获得在打开文件对话框中选择的文件的路径
            string path = ofd.FileName;
            if (path=="")
            {
                return;
            }
            using (FileStream fsRead = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read))
            {
                byte[] buffer = new byte[1024 * 1024 * 5];
                int r= fsRead.Read(buffer, 0, buffer.Length);
                textBox1.Text = Encoding.Default.GetString(buffer, 0, r);
            }
        }
    }
}