exrichtextbox.cs

该即时通讯系统系统能够实现像QQ一样的通讯功能

					// Release the device context
					_graphics.ReleaseHdc(_hdc);
				}

				// Get a graphics context from the Enhanced Metafile
				using(_graphics = Graphics.FromImage(_metaFile)) 
				{

					// Draw the image on the Enhanced Metafile
					_graphics.DrawImage(_image, new Rectangle(0, 0, _image.Width, _image.Height));

				}

				// Get the handle of the Enhanced Metafile
				IntPtr _hEmf = _metaFile.GetHenhmetafile();

				// A call to EmfToWmfBits with a null buffer return the size of the
				// buffer need to store the WMF bits.  Use this to get the buffer
				// size.
				uint _bufferSize = GdipEmfToWmfBits(_hEmf, 0, null, MM_ANISOTROPIC,
					EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);

				// Create an array to hold the bits
				byte[] _buffer = new byte[_bufferSize];

				// A call to EmfToWmfBits with a valid buffer copies the bits into the
				// buffer an returns the number of bits in the WMF.  
				uint _convertedSize = GdipEmfToWmfBits(_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC,
					EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);

				// Append the bits to the RTF string
				for(int i = 0; i < _buffer.Length; ++i) 
				{
					_rtf.Append(String.Format("{0:X2}", _buffer[i]));
				}

				return _rtf.ToString();
			}
			finally 
			{
				if(_graphics != null)
					_graphics.Dispose();
				if(_metaFile != null)
					_metaFile.Dispose();
				if(_stream != null)
					_stream.Close();
			}
		}
		
		#endregion

		#region 插入Link

		#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


		/// <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}";
			//@"par\qj\kerning2\f0\fs21 bb{\field{\*\fldinst{HYPERLINK "0001"}";

			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;
		}
		#endregion
		#region RTF Helpers

		/// <summary>
		/// Creates a font table from a font object.  When an Insert or Append 
		/// operation is performed a font is either specified or the default font
		/// is used.  In any case, on any Insert or Append, only one font is used,
		/// thus the font table will always contain a single font.  The font table
		/// should have the form ...
		/// 
		/// {\fonttbl{\f0\[FAMILY]\fcharset0 [FONT_NAME];}
		/// </summary>
		/// <param name="_font"></param>
		/// <returns></returns>
		private string GetFontTable(Font _font) 
		{

			StringBuilder _fontTable = new StringBuilder();

			// Append table control string
			_fontTable.Append(@"{\fonttbl{\f0");
			_fontTable.Append(@"\");
			
			// If the font's family corresponds to an RTF family, append the
			// RTF family name, else, append the RTF for unknown font family.
			if (rtfFontFamily.Contains(_font.FontFamily.Name))
				_fontTable.Append(rtfFontFamily[_font.FontFamily.Name]);
			else
				_fontTable.Append(rtfFontFamily[FF_UNKNOWN]);

			// \fcharset specifies the character set of a font in the font table.
			// 0 is for ANSI.
			_fontTable.Append(@"\fcharset0 ");

			// Append the name of the font
			_fontTable.Append(_font.Name);

			// Close control string
			_fontTable.Append(@";}}");

			return _fontTable.ToString();
		}

		/// <summary>
		/// Creates a font table from the RtfColor structure.  When an Insert or Append
		/// operation is performed, _textColor and _backColor are either specified
		/// or the default is used.  In any case, on any Insert or Append, only three
		/// colors are used.  The default color of the RichTextBox (signified by a
		/// semicolon (;) without a definition), is always the first color (index 0) in
		/// the color table.  The second color is always the text color, and the third
		/// is always the highlight color (color behind the text).  The color table
		/// should have the form ...
		/// 
		/// {\colortbl ;[TEXT_COLOR];[HIGHLIGHT_COLOR];}
		/// 
		/// </summary>
		/// <param name="_textColor"></param>
		/// <param name="_backColor"></param>
		/// <returns></returns>
		private string GetColorTable(RtfColor _textColor, RtfColor _backColor) 
		{

			StringBuilder _colorTable = new StringBuilder();

			// Append color table control string and default font (;)
			_colorTable.Append(@"{\colortbl ;");

			// Append the text color
			_colorTable.Append(rtfColor[_textColor]);
			_colorTable.Append(@";");

			// Append the highlight color
			_colorTable.Append(rtfColor[_backColor]);
			_colorTable.Append(@";}\n");
					
			return _colorTable.ToString();
		}

		/// <summary>
		/// Called by overrided RichTextBox.Rtf accessor.
		/// Removes the null character from the RTF.  This is residue from developing
		/// the control for a specific instant messaging protocol and can be ommitted.
		/// </summary>
		/// <param name="_originalRtf"></param>
		/// <returns>RTF without null character</returns>
		private string RemoveBadChars(string _originalRtf) 
		{			
			return _originalRtf.Replace("\0", "");
		}

		#endregion
	}
}