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 > 0)
            {
                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 > 0)
            {
                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();
        }
    }
}