如何在XNA中调整和保存Texture2D？

using System;
using System.IO;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Content;

public class TextureHelper
{
    public static Texture2D ResizeTexture(GraphicsDevice graphicsDevice, Texture2D sourceTexture, int width, int height)
    {
        Texture2D resizedTexture = new Texture2D(graphicsDevice, width, height);
        Color[] sourceColorData = new Color[sourceTexture.Width * sourceTexture.Height];
        sourceTexture.GetData(sourceColorData);
        Color[] destinationColorData = new Color[width * height];

        float sourceWidthRatio = (float)sourceTexture.Width / width;
        float sourceHeightRatio = (float)sourceTexture.Height / height;

        for (int y = 0; y< height; y++)
        {
            for (int x = 0; x< width; x++)
            {
                int sourceX = (int)Math.Floor(x * sourceWidthRatio);
                int sourceY = (int)Math.Floor(y * sourceHeightRatio);
                destinationColorData[x + y * width] = sourceColorData[sourceX + sourceY * sourceTexture.Width];
            }
        }

        resizedTexture.SetData(destinationColorData);
        return resizedTexture;
    }

    public static void SaveTextureAsPng(Texture2D texture, string filename)
    {
        using (FileStream fs = new FileStream(filename, FileMode.Create))
        {
            texture.SaveAsPng(fs, texture.Width, texture.Height);
        }
    }
}