How to: Draw an Outlined Shape
This example draws outlined ellipses and rectangles on a form.
Example
private:
void DrawEllipse()
{
System::Drawing::Pen^ myPen =
gcnew System::Drawing::Pen(System::Drawing::Color::Red);
System::Drawing::Graphics^ formGraphics;
formGraphics = this->CreateGraphics();
formGraphics->DrawEllipse(myPen, Rectangle(0, 0, 200, 300));
delete myPen;
delete formGraphics;
}
private:
void DrawRectangle()
{
System::Drawing::Pen^ myPen =
gcnew System::Drawing::Pen(System::Drawing::Color::Red);
System::Drawing::Graphics^ formGraphics;
formGraphics = this->CreateGraphics();
formGraphics->DrawRectangle(myPen, Rectangle(0, 0, 200, 300));
delete myPen;
delete formGraphics;
}
private void DrawEllipse()
{
System.Drawing.Pen myPen = new System.Drawing.Pen(System.Drawing.Color.Red);
System.Drawing.Graphics formGraphics;
formGraphics = this.CreateGraphics();
formGraphics.DrawEllipse(myPen, new Rectangle(0, 0, 200, 300));
myPen.Dispose();
formGraphics.Dispose();
}
private void DrawRectangle()
{
System.Drawing.Pen myPen = new System.Drawing.Pen(System.Drawing.Color.Red);
System.Drawing.Graphics formGraphics;
formGraphics = this.CreateGraphics();
formGraphics.DrawRectangle(myPen, new Rectangle(0, 0, 200, 300));
myPen.Dispose();
formGraphics.Dispose();
}
Private Sub DrawEllipse()
Dim myPen As New System.Drawing.Pen(System.Drawing.Color.Red)
Dim formGraphics As System.Drawing.Graphics
formGraphics = Me.CreateGraphics()
formGraphics.DrawEllipse(myPen, New Rectangle(0, 0, 200, 300))
myPen.Dispose()
formGraphics.Dispose()
End Sub
Private Sub DrawRectangle()
Dim myPen As New System.Drawing.Pen(System.Drawing.Color.Red)
Dim formGraphics As System.Drawing.Graphics
formGraphics = Me.CreateGraphics()
formGraphics.DrawRectangle(myPen, New Rectangle(0, 0, 200, 300))
myPen.Dispose()
formGraphics.Dispose()
End Sub
Compiling the Code
You cannot call this method in the Load event handler. The drawn content will not be redrawn if the form is resized or obscured by another form. To make your content automatically repaint, you should override the OnPaint method.
Robust Programming
You should always call Dispose on any objects you create that consume system resources. In the previous example, the Pen and Graphics objects were created and then disposed.
See also
Samarbeta med oss på GitHub
Källan för det här innehållet finns på GitHub, där du även kan skapa och granska ärenden och pull-begäranden. Se vår deltagarguide för mer information.
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