C++ Windows Forms L08 - GDI P1 of C++ Windows Forms Light Course

1. C++.NET
Windows Forms Course
L08- GDI Part 1
Mohammad Shaker
mohammadshakergtr.wordpress.com
C++.NET Windows Forms Course
@ZGTRShaker

3. GDI
- Part 1 -

4. What do u need to draw sth?
• Pen (stroke width, color, etc)
• Paper
• Brush to filling your drawing

5. Drawing::Graphic
• Encapsulates a GDI* + drawing surface.
• This class cannot be inherited.
___________________
• GDI* : Graphical Device Interface

6. Drawing::Graphics
private: System::Void button1_Click_5(System::Object^
sender, System::EventArgs^ e)
{
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
}

7. Drawing::Graphics
private void DrawImagePointF(PaintEventArgs e)
{
// Create image.
Image newImage = Image.FromFile("SampImag.jpg");
// Create point for upper-left corner of image.
PointF ulCorner = new PointF(100.0F, 100.0F);
// Draw image to screen.
e.Graphics.DrawImage(newImage, ulCorner);
}

8. Method
AddMetafileComment
BeginContainer()
Description
BeginContainer(Rectangle, Rectangle,
GraphicsUnit)
Adds a comment to the current Metafile.
Saves a graphics container with the current state of this Graphics and opens
and uses a new graphics container.
Saves a graphics container with the current state of this Graphics and opens
and uses a new graphics container with the specified scale transformation.
BeginContainer(RectangleF, RectangleF,
GraphicsUnit)
Saves a graphics container with the current state of this Graphics and opens
and uses a new graphics container with the specified scale transformation.
Clear
Clears the entire drawing surface and fills it with the specified background
color.
Performs a bit-block transfer of color data, corresponding to a rectangle of
pixels, from the screen to the drawing surface of the Graphics.
CopyFromScreen(Point, Point, Size)
CopyFromScreen(Point, Point, Size,
CopyPixelOperation)
Performs a bit-block transfer of color data, corresponding to a rectangle of
pixels, from the screen to the drawing surface of the Graphics.
CopyFromScreen(Int32, Int32, Int32, Int32,
Size)
Performs a bit-block transfer of the color data, corresponding to a rectangle of
pixels, from the screen to the drawing surface of the Graphics.
CopyFromScreen(Int32, Int32, Int32, Int32,
Size, CopyPixelOperation)
Performs a bit-block transfer of the color data, corresponding to a rectangle of
pixels, from the screen to the drawing surface of the Graphics.
CreateObjRef
Creates an object that contains all the relevant information required to
generate a proxy used to communicate with a remote object. (Inherited
fromMarshalByRefObject.)
Releases all resources used by this Graphics.
Draws an arc representing a portion of an ellipse specified by
a Rectangle structure.
Draws an arc representing a portion of an ellipse specified by a RectangleF
Dispose
DrawArc(Pen, Rectangle, Single, Single)
DrawArc(Pen, RectangleF, Single, Single)

9. DrawArc(Pen, Int32, Int32, Int32, Int32, Int32, Int32) Draws an arc representing a portion of an ellipse specified by a pair of coordinates, a width,
and a height.
DrawArc(Pen, Single, Single, Single, Single, Single,
Single)
Draws an arc representing a portion of an ellipse specified by a pair of coordinates, a width,
and a height.
DrawBezier(Pen, Point, Point, Point, Point)
Draws a Bézier spline defined by four Point structures.
DrawBezier(Pen, PointF, PointF, PointF, PointF)
Draws a Bézier spline defined by four PointF structures.
DrawBezier(Pen, Single, Single, Single, Single, Single, Draws a Bézier spline defined by four ordered pairs of coordinates that represent points.
Single, Single, Single)
DrawBeziers(Pen, Point[])
Draws a series of Bézier splines from an array of Point structures.
DrawBeziers(Pen, PointF[])
Draws a series of Bézier splines from an array of PointF structures.
DrawClosedCurve(Pen, Point[])
Draws a closed cardinal spline defined by an array of Point structures.
DrawClosedCurve(Pen, PointF[])
Draws a closed cardinal spline defined by an array of PointF structures.
DrawClosedCurve(Pen, Point[], Single, FillMode)
Draws a closed cardinal spline defined by an array of Point structures using a specified
tension.
DrawClosedCurve(Pen, PointF[], Single, FillMode)
Draws a closed cardinal spline defined by an array of PointF structures using a specified
tension.
DrawCurve(Pen, Point[])
Draws a cardinal spline through a specified array of Point structures.
DrawCurve(Pen, PointF[])
Draws a cardinal spline through a specified array of PointF structures.
DrawCurve(Pen, Point[], Single)
Draws a cardinal spline through a specified array of Point structures using a specified tension.

10. DrawCurve(Pen, PointF[], Single)
DrawCurve(Pen, PointF[], Int32, Int32)
Draws a cardinal spline through a specified array of PointF structures using a
specified tension.
Draws a cardinal spline through a specified array of PointF structures. The
drawing begins offset from the beginning of the array.
DrawCurve(Pen, Point[], Int32, Int32, Single)
Draws a cardinal spline through a specified array of Point structures using a
specified tension.
DrawCurve(Pen, PointF[], Int32, Int32, Single) Draws a cardinal spline through a specified array of PointF structures using a
specified tension. The drawing begins offset from the beginning of the array.
DrawEllipse(Pen, Rectangle)
Draws an ellipse specified by a bounding Rectangle structure.
DrawEllipse(Pen, RectangleF)
DrawEllipse(Pen, Int32, Int32, Int32, Int32)
Draws an ellipse defined by a bounding RectangleF.
Draws an ellipse defined by a bounding rectangle specified by coordinates for
the upper-left corner of the rectangle, a height, and a width.
DrawEllipse(Pen, Single, Single, Single, Single) Draws an ellipse defined by a bounding rectangle specified by a pair of
coordinates, a height, and a width.
DrawIcon(Icon, Rectangle)
Draws the image represented by the specified Icon within the area specified
by aRectangle structure.
DrawIcon(Icon, Int32, Int32)
DrawIconUnstretched
DrawImage(Image, Point)
DrawImage(Image, Point[])
Draws the image represented by the specified Icon at the specified
coordinates.
Draws the image represented by the specified Icon without scaling the image.
Draws the specified Image, using its original physical size, at the specified
location.
Draws the specified Image at the specified location and with the specified
shape

11. System::Drawing

12. System::Drawing
• Graphics Class :
– Can’t be inherited
• Inheritance Hierarchy :
– System::Object
System::MarshalByRefObject
System.Drawing::Graphics

13. Drawing::Point
• What will happen now?
private: System::Void button1_Click(System::Object^
sender, System::EventArgs^ e)
{
button1->Location = 30,120;
}

14. Drawing::Point

15. Drawing::Point
• What will happen now?
private: System::Void button1_Click(System::Object^
System::EventArgs^ e)
{
Drawing::Point P;
P.X = 2;
P.Y = 23;
button1->Location = P;
}
sender,

16. Drawing::Point

17. Changing the size of the form at
run time
So, what should
we do?

18. Drawing::Size
• Can we do this? Form’s size?
private: System::Void button1_Click_1(System::Object^
System::EventArgs^ e)
{
Drawing::Size S;
S.Height = 200;
S.Width = 300;
this->Size = S;
}
Yep!
sender,

19. Drawing::Size
• Can we do this?
private: System::Void button1_Click_1(System::Object^
System::EventArgs^ e)
{
Drawing::Size ^S;
S->Height = 200;
S->Width = 300;
this->Size = S;
}
sender,
Compile error
Error
1
error C2664: 'void
System::Windows::Forms::Control::Size::set(System::Drawing::Size)'
: cannot convert parameter 1 from 'System::Drawing::Size ^' to
'System::Drawing::Size'
c:userszgtrdocumentsvisual studio
2008projectsdotnet4dotnet4Form1.h 129
dotNet4

21. Drawing::Size
• Do this:
private: System::Void button1_Click_1(System::Object^
sender, System::EventArgs^ e)
{
this->Size = Drawing::Size(200,300);
}
• Or Add Drawing in using

23. Drawing::Size

24. System::Drawing::Pen
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
}

27. Let’s draw a line!

28. Graphics.DrawLine() Method
private: System::Void button1_Click_5(System::Object^
System::EventArgs^ e)
{
System::Drawing::Graphics::DrawLine(
}
sender,

30. System::Drawing::Pen
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics::DrawLine( MyPen, 2, 3, 4,5 );
}

31. Graphics.DrawLine Method
•
•
•
•
public: void DrawLine(Pen*, Point, Point);
public: void DrawLine(Pen*, PointF, PointF);
public: void DrawLine(Pen*, int, int, int, int);
public: void DrawLine(Pen*, float, float, float, float);

34. System::Drawing
• What will happen now?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics::DrawLine( MyPen, 2, 3, 4,5 );
}
Compiler error ..

36. System::Drawing
• What will happen now?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics->DrawLine( MyPen, 2, 3, 4,5 );
}
No compiler error but Runtime error when clicking button1

38. System::Drawing
• What will happen now?
private: System::Void button1_Click_5(System::Object^ sender, System::EventArgs^
e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine( MyPen, 2, 3, 50,105 );
}
A line will be drawn!

39. System::Drawing
• After clicking the button

40. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(System::Drawing::Pen(Color::Red),2,3,50,105);
}
Compiler error

42. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^
System::EventArgs^ e)
{
System::Drawing::Pen MyPen();
MyPen.Color = Color::Red;
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Compiler error
sender,

44. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^
System::EventArgs^ e)
{
System::Drawing::Pen MyPen(Color::Red );
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Compiler error
sender,

46. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^
System::EventArgs^ e)
{
System::Drawing::Pen ^MyPen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Compiler error!
sender,

48. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^
System::EventArgs^ e)
{
System::Drawing::Pen ^MyPen = gcnew Pen;
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Compiler error
sender,

50. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Color ^MyColor = gcnew Color;
MyColor = Drawing::Color::Red;
System::Drawing::Pen ^MyPen = gcnew Pen(*MyColor);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Working!

51. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Color ^MyColor = gcnew Color; // 1
MyColor = Drawing::Color::Red;
// 2
System::Drawing::Pen ^MyPen = gcnew Pen(MyColor); // 3
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Compiler error in // 3

52. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Color MyColor = gcnew Color; // 1
MyColor = Drawing::Color::Red;
// 2
System::Drawing::Pen ^MyPen = gcnew Pen(*MyColor); // 3
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Compiler error in // 1 . ^

53. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Color ^MyColor = gcnew Color; // 1
MyColor = Red;
// 2
System::Drawing::Pen ^MyPen = gcnew Pen(*MyColor); // 3
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine(MyPen, 2, 3, 50,105 );
}
Compiler error in // 2
un-declared Red

54. System::Drawing
• But remember we can just do this
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
MyGraphics->DrawLine( MyPen, 2, 3, 50,105 );
}

55. System::Drawing
• Another way!
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
Drawing::Point ^P1 = gcnew Point(50,60);
Drawing::Point ^P2 = gcnew Point(150,160);
MyGraphics->DrawLine( MyPen, *P1, *P2 );
}
What will happen?

56. System::Drawing

57. System::Drawing
• Another way!
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
Drawing::Point P1 = gcnew Point(50,60);
Drawing::Point P2 = gcnew Point(150,160);
MyGraphics->DrawLine( MyPen, *P1, *P2 );
}
What will happen?
Compiler error

58. System::Drawing
• Another way!
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
Drawing::Point P1 = gcnew Point(50,60);
Drawing::Point P2 = gcnew Point(150,160);
MyGraphics->DrawLine( MyPen, P1, P2 );
}
What will happen?
Compiler error

59. System::Drawing
• Can we do this?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
Drawing::Point P1(50,60);
Drawing::Point P2(150,160);
MyGraphics->DrawLine( MyPen, P1, P2 );
}
Works!

60. System::Drawing
• Sth wrong?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
Drawing::Point P1; P1.X = 50; P1.Y = 60;
Drawing::Point P2; P2.X = 150; P2.Y = 160;
MyGraphics->DrawLine( MyPen, P1, P2 );
}
Works!

61. System::Drawing
• What will happen now?
private: System::Void button1_Click_5(System::Object^ sender,
System::EventArgs^ e)
{
System::Drawing::Pen ^ MyPen = gcnew Pen(Color::Red);
Drawing::Graphics ^MyGraphics;
MyGraphics = pictureBox1->CreateGraphics();
Drawing::Point P1, P2;
P1.X = 50; P1.Y = 60;
P2.X = 150; P2.Y = 160;
MyGraphics->DrawLine( MyPen, P1, P2 );
P1.X = 50; P1.Y = 60;
P2.X = 510; P2.Y = 610;
MyGraphics->DrawLine( MyPen, P1, P2 );
}

62. System::Drawing
• What’s missing? Next Lesson we’ll find out!

63. Mouse!
private: System::Void panel1_MouseClick(System::Object^ sender,
System::Windows::Forms::MouseEventArgs^ e)
{
System::Drawing::Point P(0,0);
MyGraphics->DrawEllipse(MyPen,e->X,e->Y,10,10);
MyGraphics->FillEllipse(MyBrush,e->X,e->Y,10,10);
}

64. That’s it for today!