C#记事本

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;

namespace WindowsFormsApplication5
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void 打开OToolStripMenuItem_Click(object sender, EventArgs e)
{
DialogResult jieguo = openFileDialog1.ShowDialog();
if(jieguo ==DialogResult .OK )
{
if(openFileDialog1 .FilterIndex ==1)
{
richTextBox1 .LoadFile (openFileDialog1 .FileName, RichTextBoxStreamType.RichText );

}
if(openFileDialog1 .FilterIndex ==2)
{
richTextBox1 .LoadFile (openFileDialog1 .FileName ,RichTextBoxStreamType.PlainText );
}
}
}

private void 保存SToolStripMenuItem_Click(object sender, EventArgs e)
{
if (isNew==true )
{
saveFileDialog1.ShowDialog();
richTextBox1.SaveFile(saveFileDialog1.FileName, RichTextBoxStreamType.RichText);
}
else
{
richTextBox1 .SaveFile (openFileDialog1 .FileName , RichTextBoxStreamType.RichText );
}
}

private void 另存为AToolStripMenuItem_Click(object sender, EventArgs e)
{
richTextBox1 .SaveFile (openFileDialog1 .FileName ,RichTextBoxStreamType.RichText );
}
bool isNew = false;

private void 新建NToolStripMenuItem_Click(object sender, EventArgs e)
{
isNew = true;
richTextBox1.Clear();
}

private void 全选AToolStripMenuItem_Click(object sender, EventArgs e)
{
richTextBox1.SelectAll();
}
public static string chazhaostr;
public static string tihuanstr;
private void 查找ToolStripMenuItem_Click(object sender, EventArgs e)
{
find ff = new find();
ff.Show();
}
}
}