C# 文件的保存与读取

1.保存文件到指定的textBox控件中

StreamWriter sw = new StreamWriter( "D:\\1.txt");
sw.WriteLine(this.textBox1.Text);
sw.Flush();//文件流
sw.Close();//最后要关闭写入状态

2.文件另存为到用户指定的txt文件

Stream myStream;
//新建另存为对话框
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
//指定保存文件类型 这里为txt
saveFileDialog1.Filter = "txt files   (*.txt)|*.txt";
saveFileDialog1.FilterIndex = 2;
saveFileDialog1.RestoreDirectory = true;

if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
if ((myStream = saveFileDialog1.OpenFile()) != null)
{
using (StreamWriter sw = new StreamWriter(myStream))
{
sw.WriteLine(this.textBox1.Text);
}

myStream.Close();
MessageBox.Show("Saved");
}
}
}
}

3.读取txt文件到textBox中

textBox3.Text = File.ReadAllText(“D:\1.txt”);

4.读取指定的txt文件到指定的textBox中

这里写代码片

未完成DEMO

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 WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
StreamWriter sw = new StreamWriter( "D:\\1.txt");
sw.WriteLine(this.textBox1.Text);
sw.Flush();//文件流
sw.Close();//最后要关闭写入状态
}

private void button3_Click(object sender, EventArgs e)
{
// StreamReader sd = File.OpenText("D:\\1.txt");
// sd.ReadToEnd("D:\\1.txt", System.Text.Encoding.UTF8);
textBox3.Text = File.ReadAllText("D:\\1.txt");
}

private void button4_Click(object sender, EventArgs e)
{
Stream myStream;
SaveFileDialog saveFileDialog1 = new SaveFileDialog();

saveFileDialog1.Filter = "txt files   (*.txt)|*.txt";
saveFileDialog1.FilterIndex = 2;
saveFileDialog1.RestoreDirectory = true;

if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
if ((myStream = saveFileDialog1.OpenFile()) != null)
{
using (StreamWriter sw = new StreamWriter(myStream))
{
sw.WriteLine(this.textBox1.Text);
}

myStream.Close();
MessageBox.Show("Saved");
}
}
}

private void button5_Click(object sender, EventArgs e)
{
string v_OpenFolderPath = @"目录路径"; System.Diagnostics.Process.Start("explorer.exe", v_OpenFolderPath);
}

private void button6_Click(object sender, EventArgs e)
{
Stream s;
OpenFileDialog op = new OpenFileDialog();
op.Filter = "txt files    (*.txt)|*.txt";
op.FilterIndex = 2;
op.RestoreDirectory = true;
if (op.ShowDialog() == DialogResult.OK) {
if ((s = op.OpenFile()) != null) {

textBox3.Text = File.ReadAllText("");

}
}

}
}
}