文本文件的读写

// 读文件
public TextWriter w;
// 写文件
public TextReader r;
// 读文本文件
private void button1_Click(object sender, System.EventArgs e)
{
if(openFileDialog1.ShowDialog() == DialogResult.OK)
{
textBox1.Text = openFileDialog1.FileName;
r = new StreamReader(openFileDialog1.FileName, System.Text.Encoding.Default, false, 512);//用当前默认的编码方式读取，否则将会出现乱码；
richTextBox1.Text = r.ReadToEnd();
r.Close();
}
}
// 写文本文件
private void button2_Click(object sender, System.EventArgs e)
{
if(saveFileDialog1.ShowDialog() == DialogResult.OK)
{
textBox1.Text = saveFileDialog1.FileName;
w = new StreamWriter(saveFileDialog1.FileName, false,System.Text.Encoding.Default , 512);
w.Write(richTextBox1.Text);
w.Flush();
w.Close();
}
}