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Drawing Simple Lines and Shapes
Show in webframe
| Property | Value |
|---|---|
| Dock | Fill |
[Visual Basic]
Imports System.Drawing.Drawing2D
Imports Leadtools
Imports Leadtools.Drawing
Imports Leadtools.Codecs
Imports Leadtools.WinForms
[C#]
using System.Drawing.Drawing2D;
using Leadtools;
using Leadtools.Drawing;
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
' Load an image into the viewer
Dim codecs As New RasterCodecs()
rasterImageViewer1.Image = codecs.Load("C:\Users\Public\Documents\LEADTOOLS Images\Image1.cmp")
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;
// Load an image into the viewer
RasterCodecs codecs = new RasterCodecs();
rasterImageViewer1.Image = codecs.Load(@"C:\Users\Public\Documents\LEADTOOLS Images\Image1.cmp");
}
[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)
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 Transformer = New Transformer(rasterImageViewer1.Transform)
startCoords = Point.Round(t.PointToLogical(startCoords))
endCoords = Point.Round(t.PointToLogical(endCoords))
Dim startPoint As LeadPoint = New LeadPoint(startCoords.X, startCoords.Y)
Dim endPoint As LeadPoint = New LeadPoint(endCoords.X, endCoords.Y)
startPoint = rasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, startPoint)
endPoint = rasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, endPoint)
startCoords = New Point(startPoint.X, startPoint.Y)
endCoords = New Point(endPoint.X, endPoint.Y)
' create the graphics container for the image and draw the line
Using container As RasterImageGdiPlusGraphicsContainer = New RasterImageGdiPlusGraphicsContainer(rasterImageViewer1.Image)
Using pen As 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
End Using
End Using
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 Transformer = New Transformer(rasterImageViewer1.Transform)
rectangleCoords = Rectangle.Round(t.RectangleToLogical(rectangleCoords))
Dim rectCoords As LeadRect = New LeadRect(rectangleCoords.Left, rectangleCoords.Top, rectangleCoords.Width, rectangleCoords.Height)
rectCoords = rasterImageViewer1.Image.RectangleToImage(RasterViewPerspective.TopLeft, rectCoords)
rectangleCoords = New Rectangle(rectCoords.Left, rectCoords.Top, rectCoords.Width, rectCoords.Height)
' create the graphics container for the image and draw the rectangle or ellipse
Using container As RasterImageGdiPlusGraphicsContainer = New RasterImageGdiPlusGraphicsContainer(rasterImageViewer1.Image)
Using pen As Pen = New Pen(Color.Yellow, 2)
' 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
End Using
End Using
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));
LeadPoint startPoint = new LeadPoint(startCoords.X, startCoords.Y);
LeadPoint endPoint = new LeadPoint(endCoords.X, endCoords.Y);
startPoint = rasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, startPoint);
endPoint = rasterImageViewer1.Image.PointToImage(RasterViewPerspective.TopLeft, endPoint);
startCoords = new Point(startPoint.X, startPoint.Y);
endCoords = new Point(endPoint.X, endPoint.Y);
// create the graphics container for the image and draw the line
using (RasterImageGdiPlusGraphicsContainer container = new RasterImageGdiPlusGraphicsContainer(rasterImageViewer1.Image))
{
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));
LeadRect rectCoords = new LeadRect(rectangleCoords.Left, rectangleCoords.Top, rectangleCoords.Width, rectangleCoords.Height);
rectCoords = rasterImageViewer1.Image.RectangleToImage(RasterViewPerspective.TopLeft, rectCoords);
rectangleCoords = new Rectangle(rectCoords.Left, rectCoords.Top, rectCoords.Width, rectCoords.Height);
// create the graphics container for the image and draw the rectangle or ellipse
using (RasterImageGdiPlusGraphicsContainer container = new RasterImageGdiPlusGraphicsContainer(rasterImageViewer1.Image))
{
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;
}
NOTE: If you encounter an "Invalid File Format" or "Feature Not Supported" exception, please refer to the topic Invalid File Format/Feature Not Supported.
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