C#转换文件大小格式（GB/MB/KB/B）

public static string GetString(this HtmlHelper htmlHelper, long b)

{

const int GB = 1024 * 1024 * 1024;

const int MB = 1024 * 1024;

const int KB = 1024;

if (b / GB >= 1)

{

return Math.Round(b / (float)GB, 2) + "GB";

}

if (b / MB >= 1)

{

return Math.Round(b / (float)MB, 2) + "MB";

}

if (b / KB >= 1)

{

return Math.Round(b / (float)KB, 2) + "KB";

}

return b + "B";

}