File类，FileInfo，StreamReader类，StreamWriter类.下面就写一读写文本个小例子。
1。通过FileStream 中的read方法来读。
private void Form1_Load(object sender, EventArgs e)
{
FileInfo fl = new FileInfo(Application.StartupPath + @"/test.txt");
using (FileStream fs = fl.OpenRead())
{
byte[] byt = new byte[fl.Length];
fs.Read(byt, 0, byt.Length);
fs.Close();
this.textBox1.Text = System.Text.Encoding.Default.GetString(byt);
}
}
2.通过FileStream中的Write方法来写。
private void button1_Click(object sender, EventArgs e)
{
FileInfo fl = new FileInfo(Application.StartupPath + @"/test.txt");
using(FileStream fs=File.Open(Application.StartupPath+@"/test.txt",FileMode.Append))
{
byte []byt=System.Text.Encoding.Default.GetBytes(this.textBox1.Text);
fs.Write(byt, 0, byt.Length);
fs.Close();
}
}
3.通过StreamReader类中的ReadtoEnd()方法来读。
FileStream fl=File.Open(Application.StartupPath+@"/test.txt",FileMode.Open)
using(StreamReader sr=new StreamReader(fl,Encoding.Default))
{
this.TextBox1.Text=sr.ReadtoEnd();
}
4.通过StreamWriter类中的Write和WriteLine来写。
private void button1_Click(object sender, EventArgs e)
{
FileInfo fs = new FileInfo(Application.StartupPath + @"/test.txt");
using (StreamWriter sw = fs.CreateText())
{
sw.Write("fdsa");
}
}