C# RichTextBox 制作文本编辑器

本文利用一个简单的小例子【文本编辑器】，讲解RichTextBox的用法，仅供学习分享使用，如有不足之处，还请指正。

Windows窗体中的RichTextBox控件用于显示，输入和操作格式化的文本，RichTextBox除了拥有TextBox控件的所有功能外，还可以显示字体，颜色，链接，从文件中读取和加载图像，以及查找指定的字符。RichTextBox控件通常用于提供类似字体处理程序（如Microsoft Word）的文本操作和显示功能。RichTextBox控件可以显示滚动条，且默认根据需要进行显示。

涉及知识点：

• SelectionFont 获取或设置当前选定文本或插入点的字体。
• FontStyle 指定应用到文本的字形信息。
• SelectionAlignment  获取或设置应用到当前选定内容或插入点的对齐方式。
• SelectionIndent 获取或设置所选内容开始行的缩进距离（以像素为单位）。
• SelectionCharOffset 获取或设置控件中的文本是显示在基线上、作为上标还是作为基线下方的下标。
• SelectionColor 获取或设置当前选定文本或插入点的文本颜色。
• SelectionBackColor   获取或设置在 System.Windows.Forms.RichTextBox 控件中选中文本时文本的颜色。
• SelectionBullet 获取或设置一个值，通过该值指示项目符号样式是否应用到当前选定内容或插入点。
• Clipboard Paste 粘贴指定剪贴板格式的剪贴板内容【插入图片时使用】。
• Find 在对搜索应用特定选项的情况下，在 System.Windows.Forms.RichTextBox 控件的文本中搜索位于控件内特定位置的字符串。

效果图

如下【以下设置文本对应的格式】：

核心代码

如下

 using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Drawing.Printing;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Windows.Forms;

 namespace DemoRichText.Model
 {
     public class DefaultRickFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {

         }
     }

     /// <summary>
     /// 加粗格式
     /// </summary>
     public class BoldRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             Font oldFont = rtbInfo.SelectionFont;
             Font newFont;
             if (oldFont.Bold)
             {
                 newFont = new Font(oldFont, oldFont.Style & ~FontStyle.Bold);//支持位于运算
             }
             else
             {
                 newFont = new Font(oldFont, oldFont.Style | FontStyle.Bold);
             }
             rtbInfo.SelectionFont = newFont;
         }
     }

     /// <summary>
     /// 斜体
     /// </summary>
     public class ItalicRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             Font oldFont = rtbInfo.SelectionFont;
             Font newFont;
             if (oldFont.Italic)
             {
                 newFont = new Font(oldFont, oldFont.Style & ~FontStyle.Italic);
             }
             else
             {
                 newFont = new Font(oldFont, oldFont.Style | FontStyle.Italic);
             }
             rtbInfo.SelectionFont = newFont;
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 下划线
     /// </summary>
     public class UnderLineRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             Font oldFont = rtbInfo.SelectionFont;
             Font newFont;
             if (oldFont.Underline)
             {
                 newFont = new Font(oldFont, oldFont.Style & ~FontStyle.Underline);
             }
             else
             {
                 newFont = new Font(oldFont, oldFont.Style | FontStyle.Underline);
             }
             rtbInfo.SelectionFont = newFont;
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 删除线
     /// </summary>
     public class StrikeLineRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             Font oldFont = rtbInfo.SelectionFont;
             Font newFont;
             if (oldFont.Underline)
             {
                 newFont = new Font(oldFont, oldFont.Style & ~FontStyle.Strikeout);
             }
             else
             {
                 newFont = new Font(oldFont, oldFont.Style | FontStyle.Strikeout);
             }
             rtbInfo.SelectionFont = newFont;
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 左对齐
     /// </summary>
     public class LeftRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             rtbInfo.SelectionAlignment = HorizontalAlignment.Left;
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 居中对齐
     /// </summary>
     public class CenterRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             if (rtbInfo.SelectionAlignment == HorizontalAlignment.Center)
             {
                 rtbInfo.SelectionAlignment = HorizontalAlignment.Left;
             }
             else
             {
                 rtbInfo.SelectionAlignment = HorizontalAlignment.Center;
             }

             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 右对齐
     /// </summary>
     public class RightRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             if (rtbInfo.SelectionAlignment == HorizontalAlignment.Right)
             {
                 rtbInfo.SelectionAlignment = HorizontalAlignment.Left;
             }
             else
             {
                 rtbInfo.SelectionAlignment = HorizontalAlignment.Right;
             }

             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 缩进对齐
     /// </summary>
     public class IndentRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             //每次以10个像素进行缩进
             rtbInfo.SelectionIndent = rtbInfo.SelectionIndent + ;
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 缩进对齐
     /// </summary>
     public class OutIndentRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             //每次以10个像素进行缩进
             rtbInfo.SelectionIndent = rtbInfo.SelectionIndent - ;
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 下标
     /// </summary>
     public class SubScriptRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             if (rtbInfo.SelectionCharOffset < )
             {
                 rtbInfo.SelectionCharOffset = ;
             }
             else {
                 rtbInfo.SelectionCharOffset = -;
             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 上标
     /// </summary>
     public class SuperScriptRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             if (rtbInfo.SelectionCharOffset > )
             {
                 rtbInfo.SelectionCharOffset = ;
             }
             else {
                 rtbInfo.SelectionCharOffset = ;
             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 字体
     /// </summary>
     public class FontRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             FontDialog f = new FontDialog();
             if (f.ShowDialog() == DialogResult.OK)
             {
                 FontFamily family = f.Font.FontFamily;
                 rtbInfo.SelectionFont = new Font(family, rtbInfo.SelectionFont.Size, rtbInfo.SelectionFont.Style);
             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 文本颜色
     /// </summary>
     public class ForeColorRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             ColorDialog f = new ColorDialog();
             if (f.ShowDialog() == DialogResult.OK)
             {

                 rtbInfo.SelectionColor = f.Color;
             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 文本背景颜色
     /// </summary>
     public class BgColorRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             ColorDialog f = new ColorDialog();
             if (f.ShowDialog() == DialogResult.OK)
             {

                 rtbInfo.SelectionBackColor = f.Color;
             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// UL列表,项目符号样式
     /// </summary>
     public class UlRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             if (rtbInfo.SelectionBullet)
             {
                 rtbInfo.SelectionBullet = false;
             }
             else {
                 rtbInfo.SelectionBullet = true;
                 rtbInfo.BulletIndent = ;
             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 图片插入
     /// </summary>
     public class PicRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             OpenFileDialog o = new OpenFileDialog();
             o.InitialDirectory = AppDomain.CurrentDomain.BaseDirectory;
             o.Title = "请选择图片";
             o.Filter = "jpeg|*.jpeg|jpg|*.jpg|png|*.png|gif|*.gif";
             if (o.ShowDialog() == DialogResult.OK) {
                 string fileName = o.FileName;
                 try
                 {
                    Image bmp = Image.FromFile(fileName);
                    Clipboard.SetDataObject(bmp);

                     DataFormats.Format dataFormat = DataFormats.GetFormat(DataFormats.Bitmap);
                     if (rtbInfo.CanPaste(dataFormat))
                     {
                         rtbInfo.Paste(dataFormat);
                     }

                 }
                 catch (Exception exc)
                 {
                     MessageBox.Show("图片插入失败。" + exc.Message, "提示",
                                     MessageBoxButtons.OK, MessageBoxIcon.Information);
                 }

             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 删除
     /// </summary>
     public class DelRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             rtbInfo.SelectedText = "";
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 查找
     /// </summary>
     public class SearchRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             string find = rtbInfo.Tag.ToString();
             int index=  rtbInfo.Find(find, ,RichTextBoxFinds.None);
             int startPos = index;
             int nextIndex = ;
             while (nextIndex != startPos)//循环查找字符串，并用蓝色加粗12号Times New Roman标记之
             {
                 rtbInfo.SelectionStart = index;
                 rtbInfo.SelectionLength = find.Length;
                 rtbInfo.SelectionColor = Color.Blue;
                 rtbInfo.SelectionFont = new Font("Times New Roman", (float), FontStyle.Bold);
                 rtbInfo.Focus();
                 nextIndex = rtbInfo.Find(find, index + find.Length, RichTextBoxFinds.None);
                 if (nextIndex == -)//若查到文件末尾，则充值nextIndex为初始位置的值，使其达到初始位置，顺利结束循环，否则会有异常。
                 {
                     nextIndex = startPos;
                 }
                 index = nextIndex;
             }
             rtbInfo.Focus();
         }
     }

     /// <summary>
     /// 打印
     /// </summary>
     public class PrintRichFormat : BaseRichFormat
     {
         private RichTextBox richTextbox;

         public override void SetFormat(RichTextBox rtbInfo)
         {
             this.richTextbox = rtbInfo;
             PrintDocument pd = new PrintDocument();
             pd.PrintPage += new PrintPageEventHandler(pd_PrintPage);
             // 打印文档
             pd.Print();
         }

         private void pd_PrintPage(object sender, PrintPageEventArgs ev)
         {
             //ev.Graphics.DrawString(richTextbox.Text);
             //ev.HasMorePages = true;
         }
     }

     /// <summary>
     /// 字体大小
     /// </summary>
     public class FontSizeRichFormat : BaseRichFormat
     {
         public override void SetFormat(RichTextBox rtbInfo)
         {
             string fontSize = rtbInfo.Tag.ToString();
             float fsize = 0.0f;
             if (float.TryParse(fontSize, out fsize)) {
                 rtbInfo.SelectionFont = new Font(rtbInfo.Font.FontFamily, fsize, rtbInfo.SelectionFont.Style);
             }
             rtbInfo.Focus();
         }
     }
 }

页面代码【由于实现了代码封装，所有页面代码较少】

 using DemoRichText.Model;
 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 DemoRichText
 {
     public partial class MainForm : Form
     {
         public MainForm()
         {
             InitializeComponent();
         }

         public void btnButtonClick(object sender, EventArgs e) {
             Button btn = (Button)sender;
             BTNType btnType;
             if (Enum.TryParse<BTNType>(btn.Tag.ToString(), out btnType)) {
                 if (btnType == BTNType.Search) {
                     if (!string.IsNullOrEmpty(this.txtSearch.Text.Trim()))
                     {
                         this.rtbInfo.Tag = this.txtSearch.Text.Trim();
                     }
                     else {
                         return;
                     }

                 }
                 IRichFormat richFomat = RichFormatFactory.CreateRichFormat(btnType);
                 richFomat.SetFormat(this.rtbInfo);
             }
         }

         private void combFontSize_SelectedIndexChanged(object sender, EventArgs e)
         {
             float fsize = 12.0f;
             if (combFontSize.SelectedIndex > -) {
                 if (float.TryParse(combFontSize.SelectedItem.ToString(), out fsize)) {
                     rtbInfo.Tag = fsize.ToString();
                     IRichFormat richFomat = RichFormatFactory.CreateRichFormat(BTNType.FontSize);
                     richFomat.SetFormat(this.rtbInfo);
                 }
                 return;
             }
         }
     }
 }

RichTextBox是一个功能丰富的控件，值得学习。

源码下载链接

源码链接