richtextbox控件插入链接代码分享

using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace RichTextBoxLinks
{
 public class RichTextBoxEx : RichTextBox
 {
  #region Interop-Defines
  [ StructLayout( LayoutKind.Sequential )]
  private struct CHARFORMAT2_STRUCT
  {
   public UInt32 cbSize;
   public UInt32   dwMask;
   public UInt32   dwEffects;
   public Int32    yHeight;
   public Int32    yOffset;
   public Int32 crTextColor;
   public byte     bCharSet;
   public byte     bPitchAndFamily;
   [MarshalAs(UnmanagedType.ByValArray, SizeConst=32)]
   public char[]   szFaceName;
   public UInt16 wWeight;
   public UInt16 sSpacing;
   public int  crBackColor; // Color.ToArgb() -> int
   public int  lcid;
   public int  dwReserved;
   public Int16 sStyle;
   public Int16 wKerning;
   public byte  bUnderlineType;
   public byte  bAnimation;
   public byte  bRevAuthor;
   public byte  bReserved1;
  }

  [DllImport("user32.dll", CharSet=CharSet.Auto)]
  private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);

  private const int WM_USER    = 0x0400;
  private const int EM_GETCHARFORMAT  = WM_USER+58;
  private const int EM_SETCHARFORMAT  = WM_USER+68;

  private const int SCF_SELECTION = 0x0001;
  private const int SCF_WORD  = 0x0002;
  private const int SCF_ALL  = 0x0004;

  #region CHARFORMAT2 Flags
  private const UInt32 CFE_BOLD  = 0x0001;
  private const UInt32 CFE_ITALIC  = 0x0002;
  private const UInt32 CFE_UNDERLINE = 0x0004;
  private const UInt32 CFE_STRIKEOUT = 0x0008;
  private const UInt32 CFE_PROTECTED = 0x0010;
  private const UInt32 CFE_LINK  = 0x0020;
  private const UInt32 CFE_AUTOCOLOR = 0x40000000;
  private const UInt32 CFE_SUBSCRIPT = 0x00010000;  /* Superscript and subscript are */
  private const UInt32 CFE_SUPERSCRIPT= 0x00020000;  /*  mutually exclusive    */

  private const int CFM_SMALLCAPS  = 0x0040;   /* (*) */
  private const int CFM_ALLCAPS  = 0x0080;   /* Displayed by 3.0 */
  private const int CFM_HIDDEN  = 0x0100;   /* Hidden by 3.0 */
  private const int CFM_OUTLINE  = 0x0200;   /* (*) */
  private const int CFM_SHADOW  = 0x0400;   /* (*) */
  private const int CFM_EMBOSS  = 0x0800;   /* (*) */
  private const int CFM_IMPRINT  = 0x1000;   /* (*) */
  private const int CFM_DISABLED  = 0x2000;
  private const int CFM_REVISED  = 0x4000;

  private const int CFM_BACKCOLOR  = 0x04000000;
  private const int CFM_LCID   = 0x02000000;
  private const int CFM_UNDERLINETYPE = 0x00800000;  /* Many displayed by 3.0 */
  private const int CFM_WEIGHT  = 0x00400000;
  private const int CFM_SPACING  = 0x00200000;  /* Displayed by 3.0 */
  private const int CFM_KERNING  = 0x00100000;  /* (*) */
  private const int CFM_STYLE   = 0x00080000;  /* (*) */
  private const int CFM_ANIMATION  = 0x00040000;  /* (*) */
  private const int CFM_REVAUTHOR  = 0x00008000;

  private const UInt32 CFM_BOLD  = 0x00000001;
  private const UInt32 CFM_ITALIC  = 0x00000002;
  private const UInt32 CFM_UNDERLINE = 0x00000004;
  private const UInt32 CFM_STRIKEOUT = 0x00000008;
  private const UInt32 CFM_PROTECTED = 0x00000010;
  private const UInt32 CFM_LINK  = 0x00000020;
  private const UInt32 CFM_SIZE  = 0x80000000;
  private const UInt32 CFM_COLOR  = 0x40000000;
  private const UInt32 CFM_FACE  = 0x20000000;
  private const UInt32 CFM_OFFSET  = 0x10000000;
  private const UInt32 CFM_CHARSET = 0x08000000;
  private const UInt32 CFM_SUBSCRIPT = CFE_SUBSCRIPT | CFE_SUPERSCRIPT;
  private const UInt32 CFM_SUPERSCRIPT= CFM_SUBSCRIPT;

  private const byte CFU_UNDERLINENONE  = 0x00000000;
  private const byte CFU_UNDERLINE   = 0x00000001;
  private const byte CFU_UNDERLINEWORD  = 0x00000002; /* (*) displayed as ordinary underline */
  private const byte CFU_UNDERLINEDOUBLE  = 0x00000003; /* (*) displayed as ordinary underline */
  private const byte CFU_UNDERLINEDOTTED  = 0x00000004;
  private const byte CFU_UNDERLINEDASH  = 0x00000005;
  private const byte CFU_UNDERLINEDASHDOT  = 0x00000006;
  private const byte CFU_UNDERLINEDASHDOTDOT = 0x00000007;
  private const byte CFU_UNDERLINEWAVE  = 0x00000008;
  private const byte CFU_UNDERLINETHICK  = 0x00000009;
  private const byte CFU_UNDERLINEHAIRLINE = 0x0000000A; /* (*) displayed as ordinary underline */

  #endregion

  #endregion

  public RichTextBoxEx()
  {
   // Otherwise, non-standard links get lost when user starts typing
   // next to a non-standard link
   this.DetectUrls = false;
  }

  [DefaultValue(false)]
  public new bool DetectUrls
  {
   get { return base.DetectUrls; }
   set { base.DetectUrls = value; }
  }

  /// <summary>
  /// Insert a given text as a link into the RichTextBox at the current insert position.
  /// </summary>
  /// <param name="text">Text to be inserted</param>
  public void InsertLink(string text)
  {
   InsertLink(text, this.SelectionStart);
  }

  /// <summary>
  /// Insert a given text at a given position as a link.
  /// </summary>
  /// <param name="text">Text to be inserted</param>
  /// <param name="position">Insert position</param>
  public void InsertLink(string text, int position)
  {
   if (position < 0 || position > this.Text.Length)
    throw new ArgumentOutOfRangeException("position");

   this.SelectionStart = position;
   this.SelectedText = text;
   this.Select(position, text.Length);
   this.SetSelectionLink(true);
   this.Select(position + text.Length, 0);
  }

  /// <summary>
  /// Insert a given text at at the current input position as a link.
  /// The link text is followed by a hash (#) and the given hyperlink text, both of
  /// them invisible.
  /// When clicked on, the whole link text and hyperlink string are given in the
  /// LinkClickedEventArgs.
  /// </summary>
  /// <param name="text">Text to be inserted</param>
  /// <param name="hyperlink">Invisible hyperlink string to be inserted</param>
  public void InsertLink(string text, string hyperlink)
  {
   InsertLink(text, hyperlink, this.SelectionStart);
  }

  /// <summary>
  /// Insert a given text at a given position as a link. The link text is followed by
  /// a hash (#) and the given hyperlink text, both of them invisible.
  /// When clicked on, the whole link text and hyperlink string are given in the
  /// LinkClickedEventArgs.
  /// </summary>
  /// <param name="text">Text to be inserted</param>
  /// <param name="hyperlink">Invisible hyperlink string to be inserted</param>
  /// <param name="position">Insert position</param>
  public void InsertLink(string text, string hyperlink, int position)
  {
   if (position < 0 || position > this.Text.Length)
    throw new ArgumentOutOfRangeException("position");

   this.SelectionStart = position;
   this.SelectedRtf = @"{\rtf1\ansi "+text+@"\v #"+hyperlink+@"\v0}";
   this.Select(position, text.Length + hyperlink.Length + 1);
   this.SetSelectionLink(true);
   this.Select(position + text.Length + hyperlink.Length + 1, 0);
  }

  /// <summary>
  /// Set the current selection's link style
  /// </summary>
  /// <param name="link">true: set link style, false: clear link style</param>
  public void SetSelectionLink(bool link)
  {
   SetSelectionStyle(CFM_LINK, link ? CFE_LINK : 0);
  }
  /// <summary>
  /// Get the link style for the current selection
  /// </summary>
  /// <returns>0: link style not set, 1: link style set, -1: mixed</returns>
  public int GetSelectionLink()
  {
   return GetSelectionStyle(CFM_LINK, CFE_LINK);
  }

  private void SetSelectionStyle(UInt32 mask, UInt32 effect)
  {
   CHARFORMAT2_STRUCT cf = new CHARFORMAT2_STRUCT();
   cf.cbSize = (UInt32)Marshal.SizeOf(cf);
   cf.dwMask = mask;
   cf.dwEffects = effect;

   IntPtr wpar = new IntPtr(SCF_SELECTION);
   IntPtr lpar = Marshal.AllocCoTaskMem( Marshal.SizeOf( cf ) );
   Marshal.StructureToPtr(cf, lpar, false);

   IntPtr res = SendMessage(Handle, EM_SETCHARFORMAT, wpar, lpar);

   Marshal.FreeCoTaskMem(lpar);
  }

  private int GetSelectionStyle(UInt32 mask, UInt32 effect)
  {
   CHARFORMAT2_STRUCT cf = new CHARFORMAT2_STRUCT();
   cf.cbSize = (UInt32)Marshal.SizeOf(cf);
   cf.szFaceName = new char[32];

   IntPtr wpar = new IntPtr(SCF_SELECTION);
   IntPtr lpar =  Marshal.AllocCoTaskMem( Marshal.SizeOf( cf ) );
   Marshal.StructureToPtr(cf, lpar, false);

   IntPtr res = SendMessage(Handle, EM_GETCHARFORMAT, wpar, lpar);

   cf = (CHARFORMAT2_STRUCT)Marshal.PtrToStructure(lpar, typeof(CHARFORMAT2_STRUCT));

   int state;
   // dwMask holds the information which properties are consistent throughout the selection:
   if ((cf.dwMask & mask) == mask)
   {
    if ((cf.dwEffects & effect) == effect)
     state = 1;
    else
     state = 0;
   }
   else
   {
    state = -1;
   }

   Marshal.FreeCoTaskMem(lpar);
   return state;
  }
 }
}