HOW TO：繪製外框形狀
這個範例會在表單上繪製橢圓形外框和矩形外框。
範例
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
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:
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;
}
編譯程式碼
您不能在 Load 事件處理常式中呼叫這個方法。 如果表單被重新調整或被另一表單遮住，將不會重新繪製表單的內容。 若要自動重新繪製內容，您應覆寫 OnPaint 方法。
穩固程式設計
對任何消耗系統資源的物件 (例如 Pen 和 Graphics 物件)，您應一律呼叫 Dispose。