如何在 WinForms 中绘制图像反射？

Question

我想在 C# (WinForms) 中绘制图像的反射，因此我需要能够水平翻转图像。我知道我可以使用 image.RotateFlip 来做到这一点，但这种方法的问题是我必须翻转图像两次，以便我可以在下一次绘制时再次将其右侧向上绘制。每个图像的每个绘制执行两次似乎很慢。

我想在绘制图像时进行翻转，所以我只需要翻转一次，但我找不到任何方法来做到这一点。这可能吗？

我考虑过的另一种方法是以某种方式翻转图形对象，正常绘制图像，然后将图形对象翻转回来，以便下一次绘制是正确的。如果这比翻转图像两次更快，可以吗？

另外，我不想在内存中保留 2 个图像，因此我无法复制图像并翻转克隆。

Answer 1

从 此处 获取此代码并检查一下是否是任何帮助。

using System;
using System.Drawing;
using System.Windows.Forms;

class ImageReflection: Form
{
     Image image = Image.FromFile("Color.jpg");

     public static void Main()
     {
          Application.Run(new ImageReflection());
     }
     public ImageReflection()
     {
          ResizeRedraw = true;

     }
     protected override void OnPaint(PaintEventArgs pea)
     {
          DoPage(pea.Graphics, ForeColor,ClientSize.Width, ClientSize.Height);
     }     
     protected void DoPage(Graphics grfx, Color clr, int cx, int cy)
     {
          int cxImage = image.Width;
          int cyImage = image.Height;

          grfx.DrawImage(image, cx / 2, cy / 2,  cxImage,  cyImage);
          grfx.DrawImage(image, cx / 2, cy / 2, -cxImage,  cyImage);
          grfx.DrawImage(image, cx / 2, cy / 2,  cxImage, -cyImage);
          grfx.DrawImage(image, cx / 2, cy / 2, -cxImage, -cyImage);
     }
}

Answer 2

编辑

<罢工>
也是这样的吗？

     draw(new Bitmap (img).rotateflip(param))

好的，rotateflip 不返回图像

看看这个，旋转翻转只需翻转一次就足够了。不？

RotateNoneFlipNone  Specifies no rotation and no flipping.
Rotate90FlipNone    Specifies a 90-degree rotation without flipping.
Rotate180FlipNone   Specifies a 180-degree rotation without flipping.
Rotate270FlipNone   Specifies a 270-degree rotation without flipping.
RotateNoneFlipX Specifies no rotation followed by a horizontal flip.
Rotate90FlipX   Specifies a 90-degree rotation followed by a horizontal flip.
Rotate180FlipX  Specifies a 180-degree rotation followed by a horizontal flip.
Rotate270FlipX  Specifies a 270-degree rotation followed by a horizontal flip.
RotateNoneFlipY Specifies no rotation followed by a vertical flip.
Rotate90FlipY   Specifies a 90-degree rotation followed by a vertical flip.
Rotate180FlipY  Specifies a 180-degree rotation followed by a vertical flip.
Rotate270FlipY  Specifies a 270-degree rotation followed by a vertical flip.
RotateNoneFlipXY    Specifies no rotation followed by a horizontal and vertical flip.
Rotate90FlipXY  Specifies a 90-degree rotation followed by a horizontal and vertical flip.
Rotate180FlipXY Specifies a 180-degree rotation followed by a horizontal and vertical flip.
Rotate270FlipXY Specifies a 270-degree rotation followed by a horizontal and vertical flip.