richtextboxextended.cs

C#编写文本编辑器源码

		/// </summary>
		[Description("Determines if auto word selection is enabled"),
		Category("Behavior")]
		public bool AutoWordSelection
		{
			get { return rtb1.AutoWordSelection; }
			set { rtb1.AutoWordSelection = value; }
		}

		/// <summary>
		/// Determines if this control can be edited
		/// </summary>
		[Description("Determines if this control can be edited"),
		Category("Behavior")]
		public bool ReadOnly
		{
			get { return rtb1.ReadOnly; }
			set 
			{
				tb1.Visible = !value;
				rtb1.ReadOnly = value;
			}
		}

		private bool _showToolBarText;

		/// <summary>
		/// Determines if the buttons on the toolbar will show there text or not
		/// </summary>
		[Description("Determines if the buttons on the toolbar will show there text or not"),
		Category("Behavior")]
		public bool ShowToolBarText
		{
			get	{ return _showToolBarText; }
			set 
			{
				_showToolBarText = value;

				if(_showToolBarText)
				{
					tbbSave.Text = "Save";
					tbbOpen.Text = "Open";
					tbbBold.Text = "Bold";
					tbbFont.Text = "Font";
					tbbFontSize.Text = "Font Size";
					tbbColor.Text = "Font Color";
					tbbItalic.Text = "Italic";
					tbbStrikeout.Text = "Strikeout";
					tbbUnderline.Text = "Underline";
					tbbLeft.Text = "Left";
					tbbCenter.Text = "Center";
					tbbRight.Text = "Right";
					tbbUndo.Text = "Undo";
					tbbRedo.Text = "Redo";
					tbbCut.Text = "Cut";
					tbbCopy.Text = "Copy";
					tbbPaste.Text = "Paste";
					tbbStamp.Text = "Stamp";
				}
				else
				{
					tbbSave.Text = "";
					tbbOpen.Text = "";
					tbbBold.Text = "";
					tbbFont.Text = "";
					tbbFontSize.Text = "";
					tbbColor.Text = "";
					tbbItalic.Text = "";
					tbbStrikeout.Text = "";
					tbbUnderline.Text = "";
					tbbLeft.Text = "";
					tbbCenter.Text = "";
					tbbRight.Text = "";
					tbbUndo.Text = "";
					tbbRedo.Text = "";
					tbbCut.Text = "";
					tbbCopy.Text = "";
					tbbPaste.Text = "";
					tbbStamp.Text = "";
				}

				this.Invalidate();
				this.Update();
			}
		}

		#endregion

		#region Change font
		/// <summary>
		///     Change the richtextbox font for the current selection
		/// </summary>
		public void ChangeFont(string fontFamily)
		{
			//This method should handle cases that occur when multiple fonts/styles are selected
			// Parameters:-
			// fontFamily - the font to be applied, eg "Courier New"

			// Reason: The reason this method and the others exist is because
			// setting these items via the selection font doen't work because
			// a null selection font is returned for a selection with more 
			// than one font!
			
			int rtb1start = rtb1.SelectionStart;				
			int len = rtb1.SelectionLength; 
			int rtbTempStart = 0;						

			// If len <= 1 and there is a selection font, amend and return
			if (len <= 1 && rtb1.SelectionFont != null)
			{
				rtb1.SelectionFont =
					new Font(fontFamily, rtb1.SelectionFont.Size, rtb1.SelectionFont.Style);
				return;
			}

			// Step through the selected text one char at a time
			rtbTemp.Rtf = rtb1.SelectedRtf;
			for(int i = 0; i < len; ++i) 
			{ 
				rtbTemp.Select(rtbTempStart + i, 1); 
				rtbTemp.SelectionFont = new Font(fontFamily, rtbTemp.SelectionFont.Size, rtbTemp.SelectionFont.Style);
			}

			// Replace & reselect
			rtbTemp.Select(rtbTempStart,len);
			rtb1.SelectedRtf = rtbTemp.SelectedRtf;
			rtb1.Select(rtb1start,len);
			return;
		}
		#endregion

		#region Change font style
		/// <summary>
		///     Change the richtextbox style for the current selection
		/// </summary>
		public void ChangeFontStyle(FontStyle style, bool add)
		{
			//This method should handle cases that occur when multiple fonts/styles are selected
			// Parameters:-
			//	style - eg FontStyle.Bold
			//	add - IF true then add else remove
			
			// throw error if style isn't: bold, italic, strikeout or underline
			if (   style != FontStyle.Bold
				&& style != FontStyle.Italic
				&& style != FontStyle.Strikeout
				&& style != FontStyle.Underline)
					throw new  System.InvalidProgramException("Invalid style parameter to ChangeFontStyle");
			
			int rtb1start = rtb1.SelectionStart;				
			int len = rtb1.SelectionLength; 
			int rtbTempStart = 0;			
			
			//if len <= 1 and there is a selection font then just handle and return
			if(len <= 1 && rtb1.SelectionFont != null)
			{
				//add or remove style 
				if (add)
					rtb1.SelectionFont = new Font(rtb1.SelectionFont, rtb1.SelectionFont.Style | style);
				else
					rtb1.SelectionFont = new Font(rtb1.SelectionFont, rtb1.SelectionFont.Style & ~style);
				
				return;
			}
			
			// Step through the selected text one char at a time	
			rtbTemp.Rtf = rtb1.SelectedRtf;
			for(int i = 0; i < len; ++i) 
			{ 
				rtbTemp.Select(rtbTempStart + i, 1); 

				//add or remove style 
				if (add)
					rtbTemp.SelectionFont = new Font(rtbTemp.SelectionFont, rtbTemp.SelectionFont.Style | style);
				else
					rtbTemp.SelectionFont = new Font(rtbTemp.SelectionFont, rtbTemp.SelectionFont.Style & ~style);
			}

			// Replace & reselect
			rtbTemp.Select(rtbTempStart,len);
			rtb1.SelectedRtf = rtbTemp.SelectedRtf;
			rtb1.Select(rtb1start,len);
			return;
		}
		#endregion

		#region Change font size
		/// <summary>
		///     Change the richtextbox font size for the current selection
		/// </summary>
		public void ChangeFontSize(float fontSize)
		{
			//This method should handle cases that occur when multiple fonts/styles are selected
			// Parameters:-
			// fontSize - the fontsize to be applied, eg 33.5
			
			if (fontSize <= 0.0)
				throw new System.InvalidProgramException("Invalid font size parameter to ChangeFontSize");
			
			int rtb1start = rtb1.SelectionStart;				
			int len = rtb1.SelectionLength; 
			int rtbTempStart = 0;

			// If len <= 1 and there is a selection font, amend and return
			if (len <= 1 && rtb1.SelectionFont != null)
			{
				rtb1.SelectionFont =
					new Font(rtb1.SelectionFont.FontFamily, fontSize, rtb1.SelectionFont.Style);
				return;
			}
			
			// Step through the selected text one char at a time
			rtbTemp.Rtf = rtb1.SelectedRtf;
			for(int i = 0; i < len; ++i) 
			{ 
				rtbTemp.Select(rtbTempStart + i, 1); 
				rtbTemp.SelectionFont = new Font(rtbTemp.SelectionFont.FontFamily, fontSize, rtbTemp.SelectionFont.Style);
			}

			// Replace & reselect
			rtbTemp.Select(rtbTempStart,len);
			rtb1.SelectedRtf = rtbTemp.SelectedRtf;
			rtb1.Select(rtb1start,len);
			return;
		}
		#endregion

		#region Change font color
		/// <summary>
		///     Change the richtextbox font color for the current selection
		/// </summary>
		public void ChangeFontColor(Color newColor)
		{
			//This method should handle cases that occur when multiple fonts/styles are selected
			// Parameters:-
			//	newColor - eg Color.Red
			
			int rtb1start = rtb1.SelectionStart;				
			int len = rtb1.SelectionLength; 
			int rtbTempStart = 0;			
			
			//if len <= 1 and there is a selection font then just handle and return
			if(len <= 1 && rtb1.SelectionFont != null)
			{
				rtb1.SelectionColor = newColor;
				return;
			}
			
			// Step through the selected text one char at a time	
			rtbTemp.Rtf = rtb1.SelectedRtf;
			for(int i = 0; i < len; ++i) 
			{ 
				rtbTemp.Select(rtbTempStart + i, 1); 

				//change color
				rtbTemp.SelectionColor = newColor;
			}

			// Replace & reselect
			rtbTemp.Select(rtbTempStart,len);
			rtb1.SelectedRtf = rtbTemp.SelectedRtf;
			rtb1.Select(rtb1start,len);
			return;
		}
		#endregion

		#region Get Font Details
		/// <summary>
		///     Returns a Font with:
		///     1) The font applying to the entire selection, if none is the default font. 
		///     2) The font size applying to the entire selection, if none is the size of the default font.
		///     3) A style containing the attributes that are common to the entire selection, default regular.
		/// </summary>		
		/// 
		public Font GetFontDetails()
		{
			//This method should handle cases that occur when multiple fonts/styles are selected
			
			int rtb1start = rtb1.SelectionStart;				
			int len = rtb1.SelectionLength; 
			int rtbTempStart = 0;

			if (len <= 1)						
			{
				// Return the selection or default font
				if (rtb1.SelectionFont != null)
					return rtb1.SelectionFont;
				else
					return rtb1.Font;
			}

			// Step through the selected text one char at a time	
			// after setting defaults from first char
			rtbTemp.Rtf = rtb1.SelectedRtf;
		
			//Turn everything on so we can turn it off one by one
			FontStyle replystyle =			
				FontStyle.Bold | FontStyle.Italic | FontStyle.Strikeout | FontStyle.Underline;
			
			// Set reply font, size and style to that of first char in selection.
			rtbTemp.Select(rtbTempStart, 1);
			string replyfont = rtbTemp.SelectionFont.Name;
			float replyfontsize = rtbTemp.SelectionFont.Size;
			replystyle = replystyle & rtbTemp.SelectionFont.Style;
			
			// Search the rest of the selection
			for(int i = 1; i < len; ++i)				
			{ 
				rtbTemp.Select(rtbTempStart + i, 1); 
				
				// Check reply for different style
				replystyle = replystyle & rtbTemp.SelectionFont.Style;
				
				// Check font
				if (replyfont != rtbTemp.SelectionFont.FontFamily.Name)
					replyfont = "";

				// Check font size
				if (replyfontsize != rtbTemp.SelectionFont.Size)
					replyfontsize = (float)0.0;
			}

			// Now set font and size if more than one font or font size was selected
			if (replyfont == "")
				replyfont = rtbTemp.Font.FontFamily.Name;

			if (replyfontsize == 0.0)
				replyfontsize = rtbTemp.Font.Size;

			// generate reply font
			Font reply 
				= new Font(replyfont, replyfontsize, replystyle);
			
			return reply;
		}
		#endregion

		#region Keyboard Handler
		private void rtb1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
		{
			if (e.Modifiers == Keys.Control)
			{
				ToolBarButton tbb = null;

				switch (e.KeyCode)
				{
					case Keys.B:
						tbb = this.tbbBold;
						break;
					case Keys.I:
						tbb = this.tbbItalic;
						break;
					case Keys.S:
						tbb = this.tbbStamp;
						break;
					case Keys.U:
						tbb = this.tbbUnderline;
						break;
					case Keys.OemMinus:
						tbb = this.tbbStrikeout;
						break;
				}
                
				if (tbb != null)
				{
					if(e.KeyCode != Keys.S) tbb.Pushed = !tbb.Pushed;
					tb1_ButtonClick(null, new ToolBarButtonClickEventArgs(tbb));
				}
			}
		}

		private void rtb1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
		{
			if((int)e.KeyChar == 9)
				e.Handled = true; // Stops Ctrl+I from inserting a tab (char HT) into the richtextbox
		}
		#endregion

	} //end class
} //end namespace