C# RichTextBox.SelectionChanged事件代码示例

private void RichTextBox1_SelectionChanged(Object sender, EventArgs e) {

   MessageBox.Show("You are in the RichTextBox.SelectionChanged event.");
}

//引入命名空间
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Drawing.Text;

public class Form1 : Form
{
    private System.Windows.Forms.RichTextBox richTextBox1;
    private System.Windows.Forms.ToolStrip toolStrip1;
    private System.Windows.Forms.ToolStripButton cmdUnderline;
    private System.Windows.Forms.ToolStripButton cmdBold;
    private System.Windows.Forms.ToolStripButton cmdItalic;
    private System.Windows.Forms.ToolStripSeparator toolStripSeparator1;
    private System.Windows.Forms.ToolStripDropDownButton lstColors;
    private System.Windows.Forms.ToolStripDropDownButton lstFonts;
    private System.Windows.Forms.ToolStripDropDownButton lstZoom;
    private System.Windows.Forms.ToolStripDropDownButton lstFontSize;
    private System.Windows.Forms.ToolStripSeparator toolStripSeparator2;
    private System.Windows.Forms.Button cmdAddImage;

  public Form1() {
        InitializeComponent();
  }
    private void richTextBox1_SelectionChanged(object sender, EventArgs e)
    {
        if (richTextBox1.SelectionFont != null)
        {
            cmdBold.Checked = richTextBox1.SelectionFont.Bold;
            cmdItalic.Checked = richTextBox1.SelectionFont.Italic;
            cmdUnderline.Checked = richTextBox1.SelectionFont.Underline;
        }
    }

    private void cmdBold_Click(object sender, EventArgs e)
    {
        if (richTextBox1.SelectionFont == null)
        {
            return;
        }

        FontStyle style = richTextBox1.SelectionFont.Style;
        
        if (richTextBox1.SelectionFont.Bold)
        {
            style &= ~FontStyle.Bold;
        }
        else
        {
            style |= FontStyle.Bold;
            
        }
        richTextBox1.SelectionFont = new Font(richTextBox1.SelectionFont, style);
    }

    private void cmdItalic_Click(object sender, EventArgs e)
    {
        if (richTextBox1.SelectionFont == null)
        {
            return;
        }
        FontStyle style = richTextBox1.SelectionFont.Style;

        if (richTextBox1.SelectionFont.Italic)
        {
            style &= ~FontStyle.Italic;
        }
        else
        {
            style |= FontStyle.Italic;
        }
        richTextBox1.SelectionFont = new Font(richTextBox1.SelectionFont, style);
    }

    private void cmdUnderline_Click(object sender, EventArgs e)
    {
        if (richTextBox1.SelectionFont == null)
        {
            return;
        }

        FontStyle style = richTextBox1.SelectionFont.Style;

        if (richTextBox1.SelectionFont.Underline)
        {
            style &= ~FontStyle.Underline;
        }
        else
        {
            style |= FontStyle.Underline;
        }
        richTextBox1.SelectionFont = new Font(richTextBox1.SelectionFont, style);
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        lstColors.DropDown.Items.Add("Red");
        lstColors.DropDown.Items.Add("Blue");
        
        InstalledFontCollection fonts = new InstalledFontCollection();
        foreach (FontFamily family in fonts.Families)
        {
            lstFonts.DropDown.Items.Add(family.Name);
        }

        lstZoom.DropDown.Items.Add("300%");             
        lstZoom.DropDown.Items.Add("200%");             
        lstZoom.DropDown.Items.Add("100%");             

        lstFontSize.DropDown.Items.Add("8");
        lstFontSize.DropDown.Items.Add("10");
        lstFontSize.DropDown.Items.Add("12");
    }

   
    private void lstColors_DropDownItemClicked(object sender, ToolStripItemClickedEventArgs e)
    {
        
      KnownColor selectedColor;
      selectedColor = (KnownColor)System.Enum.Parse(typeof(KnownColor), e.ClickedItem.Text);

        richTextBox1.SelectionColor = Color.FromKnownColor(selectedColor);
    }

    private void lstFonts_DropDownItemClicked(object sender, ToolStripItemClickedEventArgs e)
    {
        if (richTextBox1.SelectionFont == null)
        {
            richTextBox1.SelectionFont = new Font(e.ClickedItem.Text, richTextBox1.Font.Size);
        }
        richTextBox1.SelectionFont = new Font(e.ClickedItem.Text, richTextBox1.SelectionFont.Size);
    }

    private void lstZoom_DropDownItemClicked(object sender, ToolStripItemClickedEventArgs e)
    {            
        float zoomPercent = Convert.ToSingle(e.ClickedItem.Text.Trim('%'));
        richTextBox1.ZoomFactor = zoomPercent / 100;
    }

    private void lstFontSize_DropDownItemClicked(object sender, ToolStripItemClickedEventArgs e)
    {
        if (richTextBox1.SelectionFont == null)
        {
            return;
        }
        richTextBox1.SelectionFont =new Font(richTextBox1.SelectionFont.FontFamily,
            Convert.ToInt32(e.ClickedItem.Text),
            richTextBox1.SelectionFont.Style);
    }

     private void cmdAddImage_Click(object sender, EventArgs e)
    {
         Image img = Image.FromFile("winter.jpg");
         Clipboard.SetImage(img);
         
         richTextBox1.SelectionStart = 0;
         richTextBox1.Paste();

         Clipboard.Clear();
    }

    private void InitializeComponent()
    {
        this.richTextBox1 = new System.Windows.Forms.RichTextBox();
        this.toolStrip1 = new System.Windows.Forms.ToolStrip();
        this.cmdBold = new System.Windows.Forms.ToolStripButton();
        this.cmdItalic = new System.Windows.Forms.ToolStripButton();
        this.cmdUnderline = new System.Windows.Forms.ToolStripButton();
        this.toolStripSeparator1 = new System.Windows.Forms.ToolStripSeparator();
        this.lstColors = new System.Windows.Forms.ToolStripDropDownButton();
        this.lstFonts = new System.Windows.Forms.ToolStripDropDownButton();
        this.lstFontSize = new System.Windows.Forms.ToolStripDropDownButton();
        this.toolStripSeparator2 = new System.Windows.Forms.ToolStripSeparator();
        this.lstZoom = new System.Windows.Forms.ToolStripDropDownButton();
        this.cmdAddImage = new System.Windows.Forms.Button();
        this.toolStrip1.SuspendLayout();
        this.SuspendLayout();
        // 
        // richTextBox1
        // 
        this.richTextBox1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                    | System.Windows.Forms.AnchorStyles.Left)
                    | System.Windows.Forms.AnchorStyles.Right)));
        this.richTextBox1.BulletIndent = 5;
        this.richTextBox1.Location = new System.Drawing.Point(12, 37);
        this.richTextBox1.Margin = new System.Windows.Forms.Padding(5);
        this.richTextBox1.Name = "richTextBox1";
        this.richTextBox1.Size = new System.Drawing.Size(317, 197);
        this.richTextBox1.TabIndex = 0;
        this.richTextBox1.Text = "adfasdf";
        this.richTextBox1.SelectionChanged += new System.EventHandler(this.richTextBox1_SelectionChanged);
        // 
        // toolStrip1
        // 
        this.toolStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
        this.cmdBold,
        this.cmdItalic,
        this.cmdUnderline,
        this.toolStripSeparator1,
        this.lstColors,
        this.lstFonts,
        this.lstFontSize,
        this.toolStripSeparator2,
        this.lstZoom});
        this.toolStrip1.Location = new System.Drawing.Point(0, 0);
        this.toolStrip1.Name = "toolStrip1";
        this.toolStrip1.Size = new System.Drawing.Size(341, 25);
        this.toolStrip1.TabIndex = 1;
        this.toolStrip1.Text = "toolStrip1";
        // 
        // cmdBold
        // 
        this.cmdBold.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
        this.cmdBold.ImageTransparentColor = System.Drawing.Color.Magenta;
        this.cmdBold.Name = "cmdBold";
        this.cmdBold.Size = new System.Drawing.Size(31, 22);
        this.cmdBold.Text = "Bold";
        this.cmdBold.Click += new System.EventHandler(this.cmdBold_Click);
        // 
        // cmdItalic
        // 
        this.cmdItalic.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
        this.cmdItalic.ImageTransparentColor = System.Drawing.Color.Magenta;
        this.cmdItalic.Name = "cmdItalic";
        this.cmdItalic.Size = new System.Drawing.Size(34, 22);
        this.cmdItalic.Text = "Italic";
        this.cmdItalic.Click += new System.EventHandler(this.cmdItalic_Click);
        // 
        // cmdUnderline
        // 
        this.cmdUnderline.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
        this.cmdUnderline.ImageTransparentColor = System.Drawing.Color.Magenta;
        this.cmdUnderline.Name = "cmdUnderline";
        this.cmdUnderline.Size = new System.Drawing.Size(56, 22);
        this.cmdUnderline.Text = "Underline";
        this.cmdUnderline.Click += new System.EventHandler(this.cmdUnderline_Click);
        // 
        // toolStripSeparator1
        // 
        this.toolStripSeparator1.Name = "toolStripSeparator1";
        this.toolStripSeparator1.Size = new System.Drawing.Size(6, 25);
        // 
        // lstColors
        // 
        this.lstColors.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
        this.lstColors.ImageTransparentColor = System.Drawing.Color.Magenta;
        this.lstColors.Name = "lstColors";
        this.lstColors.Size = new System.Drawing.Size(45, 22);
        this.lstColors.Text = "Color";
        this.lstColors.DropDownItemClicked += new System.Windows.Forms.ToolStripItemClickedEventHandler(this.lstColors_DropDownItemClicked);
        // 
        // lstFonts
        // 
        this.lstFonts.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
        this.lstFonts.ImageTransparentColor = System.Drawing.Color.Magenta;
        this.lstFonts.Name = "lstFonts";
        this.lstFonts.Size = new System.Drawing.Size(42, 22);
        this.lstFonts.Text = "Font";
        this.lstFonts.DropDownItemClicked += new System.Windows.Forms.ToolStripItemClickedEventHandler(this.lstFonts_DropDownItemClicked);
        // 
        // lstFontSize
        // 
        this.lstFontSize.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
        this.lstFontSize.ImageTransparentColor = System.Drawing.Color.Magenta;
        this.lstFontSize.Name = "lstFontSize";
        this.lstFontSize.Size = new System.Drawing.Size(39, 22);
        this.lstFontSize.Text = "Size";
        this.lstFontSize.DropDownItemClicked += new System.Windows.Forms.ToolStripItemClickedEventHandler(this.lstFontSize_DropDownItemClicked);
        // 
        // toolStripSeparator2
        // 
        this.toolStripSeparator2.Name = "toolStripSeparator2";
        this.toolStripSeparator2.Size = new System.Drawing.Size(6, 25);
        // 
        // lstZoom
        // 
        this.lstZoom.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Text;
        this.lstZoom.ImageTransparentColor = System.Drawing.Color.Magenta;
        this.lstZoom.Name = "lstZoom";
        this.lstZoom.Size = new System.Drawing.Size(46, 22);
        this.lstZoom.Text = "Zoom";
        this.lstZoom.DropDownItemClicked += new System.Windows.Forms.ToolStripItemClickedEventHandler(this.lstZoom_DropDownItemClicked);
        // 
        // cmdAddImage
        // 
        this.cmdAddImage.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
        this.cmdAddImage.Location = new System.Drawing.Point(12, 237);
        this.cmdAddImage.Name = "cmdAddImage";
        this.cmdAddImage.Size = new System.Drawing.Size(154, 23);
        this.cmdAddImage.TabIndex = 2;
        this.cmdAddImage.Text = "Insert Image";
        this.cmdAddImage.UseVisualStyleBackColor = true;
        this.cmdAddImage.Click += new System.EventHandler(this.cmdAddImage_Click);
        // 
        // Form1
        // 
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(341, 266);
        this.Controls.Add(this.cmdAddImage);
        this.Controls.Add(this.toolStrip1);
        this.Controls.Add(this.richTextBox1);
        this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
        this.Name = "Form1";
        this.Text = "RichTextBox Test";
        this.Load += new System.EventHandler(this.Form1_Load);
        this.toolStrip1.ResumeLayout(false);
        this.toolStrip1.PerformLayout();
        this.ResumeLayout(false);
        this.PerformLayout();

    }

  [STAThread]
  static void Main()
  {
    Application.EnableVisualStyles();
    Application.Run(new Form1());
  }

}