c# - Graphics.RotateTransform() 在绘制图像后仍然存在

Question

编写包含一些图形的 WinForms 应用程序。要旋转图像，我使用 e.Graphics.RotateTransform(angle) 方法，然后绘制图像。几行之后，我调用了 e.Graphics.RotateTransform(0) 以便我没有旋转其他图像并且应该正常显示。然而，情况并非如此，似乎我之后绘制的所有内容都受到相同变换的影响。为什么 RotateTransform(0) 不重置页面的 Transform 以恢复正常？

注意:这是我代码中 _Paint 事件的结果，但这是问题所在。我已尝试包含任何可能相关的内容

e.Graphics.TranslateTransform(Chute1Rect.Width / 2 + Chute1Rect.X, Chute1Rect.Height / 2 + Chute1Rect.Y);

            if (increasing) //Chute is rotating out of the way
            {
                e.Graphics.RotateTransform(chuteAngle);

                e.Graphics.TranslateTransform(-1 * (Chute1Rect.Width / 2 + Chute1Rect.X), -1 * (Chute1Rect.Height / 2 + Chute1Rect.Y));
                e.Graphics.DrawImage(ChuteRotating, Chute1Rect);

                //These statements do not seem to be resetting the graphics drawing by the time we do the trains
                e.Graphics.TranslateTransform(Chute1Rect.Width / 2 + Chute1Rect.X, Chute1Rect.Height / 2 + Chute1Rect.Y);
                e.Graphics.RotateTransform(0);
            }
            else    //Chute is rotating into load position
            {
                if (chuteAngle == 0)    //Chute has rotated into load position
                {
                    e.Graphics.TranslateTransform(-1 * (Chute1Rect.Width / 2 + Chute1Rect.X), -1 * (Chute1Rect.Height / 2 + Chute1Rect.Y));

                    //Getting here means that the chute can be lifted & lowered because we are rotated down
                    if (lifting) //Chute is lifting out of the way
                    {
                        Chute1SlideRect.Y -= chuteDistance;
                        Chute2SlideRect.Y -= chuteDistance;

                        e.Graphics.DrawImage(ChuteSlide, Chute1SlideRect);
                        e.Graphics.DrawImage(ChuteSlide, Chute2SlideRect);
                    }
                    else    //Chute is lifting into load position
                    {
                        Chute1SlideRect.Y -= chuteDistance;
                        Chute2SlideRect.Y -= chuteDistance;

                        e.Graphics.DrawImage(ChuteSlide, Chute1SlideRect);
                        e.Graphics.DrawImage(ChuteSlide, Chute2SlideRect);
                    }

                    e.Graphics.DrawImage(ChuteJoint, Chute1JointRect);
                    e.Graphics.DrawImage(ChuteJoint, Chute2JointRect);
                }
                else
                {
                    e.Graphics.RotateTransform(chuteAngle);

                    e.Graphics.TranslateTransform(-1 * (Chute1Rect.Width / 2 + Chute1Rect.X), -1 * (Chute1Rect.Height / 2 + Chute1Rect.Y));
                    e.Graphics.DrawImage(ChuteRotating, Chute1Rect);

                    //These statements do not seem to be resetting the graphics drawing by the time we do the trains
                    e.Graphics.TranslateTransform(Chute1Rect.Width / 2 + Chute1Rect.X, Chute1Rect.Height / 2 + Chute1Rect.Y);
                    e.Graphics.RotateTransform(0);
                }
            }
//Down below here is where the trains get drawn 

Answer 1

MSDN docs没有明确说明这一点，但似乎 RotateTransform 总是修改现有的变换矩阵，在这种情况下 RotateTransform(0) 意味着“什么都不做”而不是“设置旋转回到0。”尝试以与初始角度相反的角度旋转它。

编辑:或使用 ResetTransform() ( docs ) 使事情回到开始的地方，然后从那里开始。