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