Unity --- 如何简单的判断图片是否含有 alpha channel

 var texImporter = AssetImporter.GetAtPath(assetPath) as TextureImporter;
 if (texImporter.DoesSourceTextureHaveAlpha())
 {
     Debug.Log("textures source image don't have alpha channel ");
 }
 else
 {
     Debug.Log("textures source image have alpha channel ");
 }