c# - 从 File.ReadAllBytes (byte[]) 中删除字节顺序标记

Question

我有一个 HTTPHandler，它正在读取一组 CSS 文件并将它们组合起来，然后对它们进行 GZipping。但是，一些 CSS 文件包含字节顺序标记（由于 TFS 2005 自动合并中的错误），并且在 FireFox 中，BOM 被作为实际内容的一部分读取，因此它搞砸了我的类名等。我该如何剥离出 BOM 字符？有没有一种简单的方法可以做到这一点，而无需手动通过字节数组寻找“”？

Answer 1

用示例扩展Jon 的评论。

var name = GetFileName();
var bytes = System.IO.File.ReadAllBytes(name);
System.IO.File.WriteAllBytes(name, bytes.Skip(3).ToArray());

Answer 2

扩展 JaredPar 示例以递归子目录：

using System.Linq;
using System.IO;
namespace BomRemover
{
    /// <summary>
    /// Remove UTF-8 BOM (EF BB BF) of all *.php files in current & sub-directories.
    /// </summary>
    class Program
    {
        private static void removeBoms(string filePattern, string directory)
        {
            foreach (string filename in Directory.GetFiles(directory, file  Pattern))
            {
                var bytes = System.IO.File.ReadAllBytes(filename);
                if(bytes.Length > 2 && bytes[0] == 0xEF && bytes[1] == 0xBB && bytes[2] == 0xBF)
                {
                    System.IO.File.WriteAllBytes(filename, bytes.Skip(3).ToArray()); 
                }
            }
            foreach (string subDirectory in Directory.GetDirectories(directory))
            {
                removeBoms(filePattern, subDirectory);
            }
        }
        static void Main(string[] args)
        {
            string filePattern = "*.php";
            string startDirectory = Directory.GetCurrentDirectory();
            removeBoms(filePattern, startDirectory);            
        }       
    }
}

当您尝试执行基本的 PHP 下载文件时，我发现 UTF-8 BOM 损坏文件后，我需要那段 C# 代码。

Answer 3

var text = File.ReadAllText(args.SourceFileName);
var streamWriter = new StreamWriter(args.DestFileName, args.Append, new UTF8Encoding(false));
streamWriter.Write(text);
streamWriter.Close();

Answer 4

另一种方式，假设 UTF-8 为 ASCII。

File.WriteAllText(filename, File.ReadAllText(filename, Encoding.UTF8), Encoding.ASCII);

Answer 5

For larger file, use the following code; memory efficient!

StreamReader sr = new StreamReader(path: @"<Input_file_full_path_with_byte_order_mark>", 
                    detectEncodingFromByteOrderMarks: true);

StreamWriter sw = new StreamWriter(path: @"<Output_file_without_byte_order_mark>", 
                    append: false, 
                    encoding: new UnicodeEncoding(bigEndian: false, byteOrderMark: false));

var lineNumber = 0;
while (!sr.EndOfStream)
{
    sw.WriteLine(sr.ReadLine());
    lineNumber += 1;
    if (lineNumber % 100000 == 0)
        Console.Write("\rLine# " + lineNumber.ToString("000000000000"));
}

sw.Flush();
sw.Close();