C# 旋转形状时，它与旋转的形状保持在一起

我是一名学生，对这里很陌生。我有一个课程计划来制作一个类似绘画的程序。我有一个带有DrawSelf的基类形状，包含等。矩形、椭圆和三角形的方法和类。我还有另外两个用于绘图的类DisplayProccesor和DialogProcessor，它们控制与用户的对话。这些是项目的要求

public class DisplayProcessor
{

    public DisplayProcessor()
    {
    }

    /// <summary>
    /// List of shapes
    /// </summary>
    private List<Shape> shapeList = new List<Shape>();
    public List<Shape> ShapeList
    {
        get { return shapeList; }
        set { shapeList = value; }
    }

    /// <summary>
    /// Redraws all shapes in shapeList
    /// </summary>
    public void ReDraw(object sender, PaintEventArgs e)
    {
        e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
        Draw(e.Graphics);
    }

    public virtual void Draw(Graphics grfx)
    {
        int n = shapeList.Count;
        Shape shape;

        for (int i = 0; i <= n - 1; i++)
        {
            shape = shapeList[i];
            DrawShape(grfx, shape);
        }
    }

    public virtual void DrawShape(Graphics grfx, Shape item)
    {
        item.DrawSelf(grfx);
    }
}

因此，我想旋转一个由用户选择的形状。 我试着这样做。它会旋转，但我知道：

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我很难解释你的问题。我的猜测是，当你旋转第一个形状并绘制它时。然后画另一个形状，第二个形状也会旋转

这是因为，所有DrawSelf方法都使用相同的图形引用，因此在一个方法上使用的任何转换都将影响相同上下文上的所有后续调用

您只需在每个DrawSelf-methid的末尾调用该方法即可解决此问题

public override void DrawSelf(Graphics grfx)
    {
        base.DrawSelf(grfx);

        //grfx.FillRectangle(new SolidBrush(FillColor), Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);
        //grfx.DrawRectangle(Pens.Black, Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);

        grfx.TranslateTransform(Rectangle.X + Rectangle.Width / 2, Rectangle.Y + Rectangle.Height/2);
        grfx.RotateTransform(base.RotationAngle);
        grfx.TranslateTransform(-(Rectangle.X + Rectangle.Width / 2), -(Rectangle.Y + Rectangle.Height/2));
        grfx.FillRectangle(new SolidBrush(FillColor), Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);
        grfx.DrawRectangle(Pens.Black, Rectangle.X,Rectangle.Y, Rectangle.Width, Rectangle.Height);
        grfx.ResetTransform();
    }

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我已经成功了！问题是我为每个形状绘制选择，当我旋转形状时，选择保持不旋转。我对选择做了与DrawSelf方法相同的转换，一切都很好！干杯

public class RectangleShape : Shape
{

    public override void DrawSelf(Graphics grfx)
    {
        grfx.TranslateTransform(Rectangle.X + Rectangle.Width / 2, Rectangle.Y + Rectangle.Height / 2);
        grfx.RotateTransform(base.RotationAngle);
        grfx.TranslateTransform( - (Rectangle.X + Rectangle.Width / 2), -( Rectangle.Y + Rectangle.Height / 2));
        grfx.FillRectangle(new SolidBrush(FillColor), Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);
        grfx.DrawRectangle(Pens.Black, Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);
        grfx.ResetTransform();
    }
}

public override void DrawSelf(Graphics grfx)
    {
        base.DrawSelf(grfx);

        //grfx.FillRectangle(new SolidBrush(FillColor), Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);
        //grfx.DrawRectangle(Pens.Black, Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);

        grfx.TranslateTransform(Rectangle.X + Rectangle.Width / 2, Rectangle.Y + Rectangle.Height/2);
        grfx.RotateTransform(base.RotationAngle);
        grfx.TranslateTransform(-(Rectangle.X + Rectangle.Width / 2), -(Rectangle.Y + Rectangle.Height/2));
        grfx.FillRectangle(new SolidBrush(FillColor), Rectangle.X, Rectangle.Y, Rectangle.Width, Rectangle.Height);
        grfx.DrawRectangle(Pens.Black, Rectangle.X,Rectangle.Y, Rectangle.Width, Rectangle.Height);
        grfx.ResetTransform();
    }