如题，代码如下

using UnityEngine;
using UnityEditor;
using System.IO;public class SplitTexture
{[MenuItem("ExtraTools/SplitTexture")]static void DoSplitTexture(){// 获取所选图片Texture2D selectedImg = Selection.activeObject as Texture2D;string rootPath = Path.GetDirectoryName(AssetDatabase.GetAssetPath(selectedImg));string path = rootPath + "/" + selectedImg.name + ".png";TextureImporter texImp = AssetImporter.GetAtPath(path) as TextureImporter;// 设置为可读texImp.isReadable = true;AssetDatabase.ImportAsset(path);// 创建文件夹AssetDatabase.CreateFolder(rootPath, selectedImg.name);foreach (SpriteMetaData metaData in texImp.spritesheet){var width = (int)metaData.rect.width;var height = (int)metaData.rect.height;Texture2D smallImg = new Texture2D(width, height);var pixelStartX = (int)metaData.rect.x;var pixelEndX = pixelStartX + width;var pixelStartY = (int)metaData.rect.y;var pixelEndY = pixelStartY + height;for (int x = pixelStartX; x <= pixelEndX; ++x){for (int y = pixelStartY; y <= pixelEndY; ++y){smallImg.SetPixel(x - pixelStartX, y - pixelStartY, selectedImg.GetPixel(x, y));}}//  转换纹理到EncodeToPNG兼容格式if (TextureFormat.ARGB32 != smallImg.format  && TextureFormat.RGB24 != smallImg.format){Texture2D img = new Texture2D(smallImg.width, smallImg.height);img.SetPixels(smallImg.GetPixels(0), 0);smallImg = img;}// 保存小图文件string smallImgPath = rootPath + "/" + selectedImg.name + "/" + metaData.name + ".png";File.WriteAllBytes(smallImgPath, smallImg.EncodeToPNG());// 刷新资源窗口界面AssetDatabase.Refresh();// 设置小图的格式TextureImporter smallTextureImp = AssetImporter.GetAtPath(smallImgPath) as TextureImporter;// 设置为可读smallTextureImp.isReadable = true;// 设置alpha通道smallTextureImp.alphaIsTransparency = true;// 不开启mipmapsmallTextureImp.mipmapEnabled = false;AssetDatabase.ImportAsset(smallImgPath);}}
}