unity sprite保存成PNG图片

图集拆分后可以将子图单独保存成png图片，使用如下代码，
var sprites = Resources.LoadAll("main");
Debug.Log("拆分的图片如下:");
var path = "D:/Splite/";
if (!Directory.Exists(path))
{
    Directory.CreateDirectory(path);
}
int counter = 0;
foreach (var sprite in sprites)
{
    Debug.Log(sprite.name);
    string fname = path + sprite.name + ".png";
    if (sprite.name.Contains("/"))
    {
        var index = sprite.name.LastIndexOf("/");
        var pt = path + sprite.name.Substring(0, index);
        if(!Directory.Exists(pt))
        {
            Directory.CreateDirectory(pt);
            Debug.Log($"创建目录{pt}");
        }
        fname = path + sprite.name + ".png";
    }
    byte[] bytes = ToPNG(sprite);
    File.WriteAllBytes(fname, bytes);
    ++counter;
    if (counter > 100)
    {
        break;
    }
}
Debug.Log($"保存到目录{path},