如何将system.drawing.image转换成Sixlabors.imagesharp.pixelformats.Rgba32

可以使用ImageSharp库进行转换，示例代码如下：

using SixLabors.ImageSharp;
using SixLabors.ImageSharp.PixelFormats;
using System.Drawing;

public Rgba32[,] ConvertToRgba32(Bitmap bitmap)
{
    using (var image = Image.Load(bitmap))
    {
        var pixelBuffer = image.Frames[0].PixelBuffer;
        var pixelWidth = image.Width;
        var pixelHeight = image.Height;

        var bitmapPixels = new Rgba32[pixelHeight, pixelWidth];

        for (var y = 0; y < pixelHeight; y++)
        {
            for (var x = 0; x < pixelWidth; x++)
            {
                bitmapPixels[y, x] = pixelBuffer.GetRowSpan(y)[x].ToRgba32();
            }
        }

        return bitmapPixels;
    }
}

该函数将给定的`Bitmap`对象转换为`Rgba32`像素格式的二维数组，并返回该数组。