WinForm 小程序 NotePad

运行效果：

代码：

 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 FreeNotes
 {
     public partial class NotePad : Form
     {
         public NotePad()
         {
             InitializeComponent();
         }

         /// <summary>
         /// 打开文件事件
         /// </summary>
         private void btn_Open_Click(object sender, EventArgs e)
         {
             OpenFileDialog of = new OpenFileDialog();

             of.DefaultExt = "*.rtf";

             of.Filter = "rtf文件(*.rtf)|*.rtf|所有文件(*.*)|*.*";

             if (of.ShowDialog() == DialogResult.OK && of.FileName.Length > )
             {
                 richTextBox1.LoadFile(of.FileName, RichTextBoxStreamType.RichText);
             }
         }

         /// <summary>
         /// 保存文件事件
         /// </summary>
         private void btn_Save_Click(object sender, EventArgs e)
         {
             SaveFileDialog sa = new SaveFileDialog();

             sa.Title = "保存";

             sa.FileName = "*.rtf";

             sa.Filter = "rtf文件(*.rtf)|*.rtf|所有文件(*.*)|*.*";

             sa.DefaultExt = "*.rtf";

             if (sa.ShowDialog() == DialogResult.OK && sa.FileName.Length > )
             {
                 richTextBox1.SaveFile(sa.FileName, RichTextBoxStreamType.RichText);
             }
         }

         /// <summary>
         /// 字体事件
         /// </summary>
         private void btn_Font_Click(object sender, EventArgs e)
         {
             FontDialog fda = new FontDialog();

             fda.ShowColor = true;

             if (fda.ShowDialog() != DialogResult.Cancel)
             {
                 richTextBox1.SelectionFont = fda.Font;
                 richTextBox1.SelectionColor = fda.Color;
             }
         }

         /// <summary>
         /// 清空文本事件
         /// </summary>
         private void btn_Clear_Click(object sender, EventArgs e)
         {
             richTextBox1.Clear();
         }
     }
 }