• Leadtools.dll
• Leadtools.Codecs.dll
• Leadtools.WinForms.dll

[Visual Basic]

Imports System.Drawing.Drawing2D
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.WinForms

[C#]

using System.Drawing.Drawing2D;
using Leadtools;
using Leadtools.Codecs;
using Leadtools.WinForms;

[Visual Basic]

' what shape we are drawing
Private Enum ShapeType
   Line
   Rectangle
   Ellipse
End Enum

' shape we are currently drawing
Private shape As ShapeType

' start and end point for the line
Private startCoords As Point
Private endCoords As Point

' coordinate for the rectangle and the ellipse
Private rectangleCoords As Rectangle

' are we currently drawing or not
Private drawing As Boolean

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   ' Initialize the private varibles
   shape = ShapeType.Line
   drawing = False
   
   RasterCodecs.Startup()
   ' Load an image into the viewer
   Dim codecs As New RasterCodecs()
   rasterImageViewer1.Image = codecs.Load("C:\Users\Public\Documents\LEADTOOLS Images\Image1.cmp")
   RasterCodecs.Shutdown()
End Sub

[C#]

// what shape we are drawing
private enum ShapeType
{
   Line,
   Rectangle,
   Ellipse
}

// shape we are currently drawing
ShapeType shape;

// start and end point for the line
private Point startCoords;
private Point endCoords;

// coordinate for the rectangle and the ellipse
private Rectangle rectangleCoords;

// are we currently drawing or not
private bool drawing;

private void Form1_Load(object sender, System.EventArgs e)
{
   // Initialize the private varibles
   shape = ShapeType.Line;
   drawing = false;
   
   RasterCodecs.Startup();
   // Load an image into the viewer
   RasterCodecs codecs = new RasterCodecs();
   rasterImageViewer1.Image = codecs.Load(@"C:\Users\Public\Documents\LEADTOOLS Images\Image1.cmp");
   RasterCodecs.Shutdown();
}

[Visual Basic]

Private Sub RasterImageViewer1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles RasterImageViewer1.MouseDown
   ' check if we are already drawing, if so cancel it
   If (drawing) Then
      ' erase the shape
      DrawShape()
      drawing = False
   
   Else
      ' based on shape, initialize the coordinates
      Select Case (shape)
         Case ShapeType.Line
            ' drawing a line
            startCoords = New Point(e.X, e.Y)
            endCoords = startCoords
            
         Case ShapeType.Rectangle
         Case ShapeType.Ellipse
            ' drawing a rectangle or an ellipse
            rectangleCoords = New Rectangle(e.X, e.Y, 0, 0)
      End Select
      
      ' draw the shape
      drawing = True
      DrawShape()
   End If
End Sub

[C#]

private void rasterImageViewer1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e) 
{
   // check if we are already drawing, if so cancel it
   if(drawing)
   {
      // erase the shape
      DrawShape();
      drawing = false;
   }
   else
   {
      // based on shape, initialize the coordinates
      switch(shape)
      {
         case ShapeType.Line:
            // drawing a line
            startCoords = new Point(e.X, e.Y);
            endCoords = startCoords;
            break;
         
         case ShapeType.Rectangle:
         case ShapeType.Ellipse:
            // drawing a rectangle or an ellipse
            rectangleCoords = new Rectangle(e.X, e.Y, 0, 0);
            break;
      }
      
      // draw the shape
      drawing = true;
      DrawShape();
   }
}

[Visual Basic]

Private Sub RasterImageViewer1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles RasterImageViewer1.MouseMove
   If (drawing) Then
      ' first, erase the shape
      DrawShape()
      
      ' get new coords for the shape
      Select Case (shape)
         Case ShapeType.Line
            endCoords = New Point(e.X, e.Y)
         
         Case ShapeType.Rectangle, ShapeType.Ellipse
            rectangleCoords = Rectangle.FromLTRB(rectangleCoords.Left, rectangleCoords.Top, e.X, e.Y)
      End Select
      
      ' draw the shape again
      DrawShape()
   End If
End Sub

[C#]

private void rasterImageViewer1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{     
   if(drawing)
   {
      // first, erase the shape
      DrawShape();
      
      // get new coords for the shape
      switch(shape)
      {
         case ShapeType.Line:
            endCoords = new Point(e.X, e.Y);
            break;
         
         case ShapeType.Rectangle:
         case ShapeType.Ellipse:
            rectangleCoords = Rectangle.FromLTRB(rectangleCoords.Left, rectangleCoords.Top, e.X, e.Y);
            break;
      }

      // draw the shape again
      DrawShape();
   }
}

[Visual Basic]

Private Sub RasterImageViewer1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles RasterImageViewer1.MouseUp
   If (drawing) Then
      ' erase the shape
      DrawShape()
      drawing = False
      
      ' draw the shape on the image
      Select Case (shape)
         Case ShapeType.Line
            If (startCoords.X <> endCoords.X OrElse startCoords.Y <> endCoords.Y) Then
               ' convert the points to image coordinates
               Dim t As New Transformer(RasterImageViewer1.Transform)
               startCoords = Point.Round(t.PointToLogical(New PointF(startCoords.X, startCoords.Y)))
               endCoords = Point.Round(t.PointToLogical(New PointF(endCoords.X, endCoords.Y)))
               startCoords = RasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, startCoords)
               endCoords = RasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, endCoords)
               
               ' create the graphics container for the image and draw the line
               Dim container As RasterImageGdiPlusGraphicsContainer = RasterImageViewer1.Image.CreateGdiPlusGraphics()
               Try
                  Dim pen As New Pen(Color.Yellow, 2)
                  Try
                     ' use anti-alias lines
                     container.Graphics.SmoothingMode = SmoothingMode.AntiAlias
                     container.Graphics.DrawLine(pen, startCoords, endCoords)
                     
                     ' draw a rectangle next
                     shape = ShapeType.Rectangle
                  Finally
                     pen.Dispose()
                  End Try
               Finally
                  container.Dispose()
               End Try
               
               
               RasterImageViewer1.Invalidate()
            End If
            
            case ShapeType.Rectangle, ShapeType.Ellipse:
               ' "fix" the rectangle so it does not have a negative width or height
               rectangleCoords = FixRectangle(rectangleCoords)
               If (Not rectangleCoords.IsEmpty) Then
                  ' convert the rectangle to image coordinates
                  Dim t As New Transformer(RasterImageViewer1.Transform)
                  rectangleCoords = Rectangle.Round(t.RectangleToLogical(New RectangleF(rectangleCoords.Left, rectangleCoords.Top, rectangleCoords.Width, rectangleCoords.Height)))
                  rectangleCoords = RasterImageViewer1.Image.RectangleToImage(RasterViewPerspective.TopLeft, rectangleCoords)
                  
                  ' create the graphics container for the image and draw the rectangle or ellipse
                  Dim container As RasterImageGdiPlusGraphicsContainer = RasterImageViewer1.Image.CreateGdiPlusGraphics()
                  Try
                     Dim pen As New Pen(Color.Yellow, 2)
                     Try
                        ' use anti-alias lines
                        container.Graphics.SmoothingMode = SmoothingMode.AntiAlias
                        
                        If (shape = ShapeType.Rectangle) Then
                           container.Graphics.DrawRectangle(pen, rectangleCoords)
                           
                           ' draw an ellipse next
                           shape = ShapeType.Ellipse
                        Else
                           container.Graphics.DrawEllipse(pen, rectangleCoords)
                           ' draw a line next
                           shape = ShapeType.Line
                        End If
                     Finally
                        pen.Dispose()
                     End Try
                  Finally
                     container.Dispose()
                  End Try
                     
                  RasterImageViewer1.Invalidate()
            End If
      End Select
   End If
End Sub

[C#]

private void rasterImageViewer1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e) 
{
   if(drawing)
   {
      // erase the shape
      DrawShape();
      drawing = false;
      
      // draw the shape on the image
      switch(shape)
      {
         case ShapeType.Line:
            if(startCoords.X != endCoords.X || startCoords.Y != endCoords.Y)
            {
               // convert the points to image coordinates
               Transformer t = new Transformer(rasterImageViewer1.Transform);
               startCoords = Point.Round(t.PointToLogical(startCoords));
               endCoords = Point.Round(t.PointToLogical(endCoords));
               startCoords = rasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, startCoords);
               endCoords = rasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, endCoords);
               
               // create the graphics container for the image and draw the line
               using(RasterImageGdiPlusGraphicsContainer container = rasterImageViewer1.Image.CreateGdiPlusGraphics())
               {
                  using(Pen pen = new Pen(Color.Yellow, 2))
                  {
                     // use anti-alias lines
                     container.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
                     container.Graphics.DrawLine(pen, startCoords, endCoords);
                     
                     // draw a rectangle next
                     shape = ShapeType.Rectangle;
                  }
               }
               
               rasterImageViewer1.Invalidate();
            }
            break;
         
         case ShapeType.Rectangle:
         case ShapeType.Ellipse:
            // "fix" the rectangle so it does not have a negative width or height
            rectangleCoords = FixRectangle(rectangleCoords);
            if(!rectangleCoords.IsEmpty)
            {
               // convert the rectangle to image coordinates
               Transformer t = new Transformer(rasterImageViewer1.Transform);
               rectangleCoords = Rectangle.Round(t.RectangleToLogical(rectangleCoords));
               rectangleCoords = rasterImageViewer1.Image.RectangleToImage(RasterViewPerspective.TopLeft, rectangleCoords);
               
               // create the graphics container for the image and draw the rectangle or ellipse
               using(RasterImageGdiPlusGraphicsContainer container = rasterImageViewer1.Image.CreateGdiPlusGraphics())
               {
                  using(Pen pen = new Pen(Color.Yellow, 2))
                  {
                     // use anti-alias lines
                     container.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
                     
                     if(shape == ShapeType.Rectangle)
                     {
                        container.Graphics.DrawRectangle(pen, rectangleCoords);
                        
                        // draw an ellipse next
                        shape = ShapeType.Ellipse;
                     }
                     else
                     {
                        container.Graphics.DrawEllipse(pen, rectangleCoords);
                        // draw a line next
                        shape = ShapeType.Line;
                     }
                  }
               }
               
               rasterImageViewer1.Invalidate();
            }
            break;
      }
   }
}

[Visual Basic]

Private Sub DrawShape()
   ' draw the shape on screen (reversible)
   Select Case (shape)
      Case ShapeType.Line
         ControlPaint.DrawReversibleLine(RasterImageViewer1.PointToScreen(startCoords), RasterImageViewer1.PointToScreen(endCoords), Color.Transparent)
      
      Case ShapeType.Rectangle, ShapeType.Ellipse
         ' "fix" the rectangle so it does not have a negative width or height
         Dim rc As Rectangle = FixRectangle(rectangleCoords)
         ControlPaint.DrawReversibleFrame(RasterImageViewer1.RectangleToScreen(rc), Color.Transparent, FrameStyle.Thick)
   End Select
End Sub
Shared Function FixRectangle(ByVal rc As Rectangle) As Rectangle
   If (rc.Left > rc.Right OrElse rc.Top > rc.Bottom) Then
      Return Rectangle.FromLTRB( _
         Math.Min(rc.Left, rc.Right), _
         Math.Min(rc.Top, rc.Bottom), _
         Math.Max(rc.Left, rc.Right), _
         Math.Max(rc.Top, rc.Bottom))
   Else
      Return rc
   End If
End Function

[C#]

private void DrawShape()
{
   // draw the shape on screen (reversible)
   switch(shape)
   {
      case ShapeType.Line:
         ControlPaint.DrawReversibleLine(rasterImageViewer1.PointToScreen(startCoords), rasterImageViewer1.PointToScreen(endCoords), Color.Transparent);
         break;
         
      case ShapeType.Rectangle:
      case ShapeType.Ellipse:
         // "fix" the rectangle so it does not have a negative width or height
         Rectangle rc = FixRectangle(rectangleCoords);
         ControlPaint.DrawReversibleFrame(rasterImageViewer1.RectangleToScreen(rc), Color.Transparent, FrameStyle.Thick);
         break;
   }
}
static Rectangle FixRectangle(Rectangle rc)
{
   if(rc.Left > rc.Right || rc.Top > rc.Bottom)
      return Rectangle.FromLTRB(
         Math.Min(rc.Left, rc.Right),
         Math.Min(rc.Top, rc.Bottom),
         Math.Max(rc.Left, rc.Right),
         Math.Max(rc.Top, rc.Bottom));
   else
      return rc;
}

1. Select the form1.
2. Click "Shift + F7", Or right-click and select "View Designer", Or click in the "View Designer" button in the top of the solution explorer window.
3. Click in the "rasterImageViewer1" from the form.
4. In the properties window click on the "Events" button.
5. Click on the "Categorized" button to sort the events by category.
6. Goto the mouse category. • Select the "rasterImageViewer1_MouseDown" to the "MouseDown" event.
7. Select the "rasterImageViewer1_MouseMove" to the "MouseMove" event.
8. Select the "rasterImageViewer1_MouseUp" to the "MouseUp" event.