将 Unicode 转换为用于 vCard 的 Windows-1252

问题描述

我正在尝试用 C# 编写一个程序，该程序会将包含多个联系人的 vCard (VCF) 文件拆分为每个联系人的单独文件.我知道大多数手机需要将电子名片保存为 ANSI (1252) 才能读取它们.

I am trying to write a program in C# that will split a vCard (VCF) file with multiple contacts into individual files for each contact. I understand that the vCard needs to be saved as ANSI (1252) for most mobile phones to read them.

但是，如果我使用 StreamReader 打开一个 VCF 文件，然后使用 StreamWriter(设置 1252 作为编码格式)将其写回，所有特殊字符如 ?、? 和 ? 被写成 ?.ANSI (1252) 肯定会支持这些字符.我该如何解决这个问题?

However, if I open a VCF file using StreamReader and then write it back with StreamWriter (setting 1252 as the Encoding format), all special characters like ?, ? and ? are getting written as ?. Surely ANSI (1252) would support these characters. How do I fix this?

这是我用来读写文件的一段代码.

Here's the piece of code I use to read and write the file.

private void ReadFile()
{
   StreamReader sreader = new StreamReader(sourceVCFFile);
   string fullFileContents = sreader.ReadToEnd();
}

private void WriteFile()
{
   StreamWriter swriter = new StreamWriter(sourceVCFFile, false, Encoding.GetEncoding(1252));
   swriter.Write(fullFileContents);
}

推荐答案

您正确地假设 Windows-1252 支持上面列出的特殊字符(有关完整列表，请参阅 维基百科条目).

You are correct in assuming that Windows-1252 supports the special characters you listed above (for a full list see the Wikipedia entry).

using (var writer = new StreamWriter(destination, true, Encoding.GetEncoding(1252)))
{
    writer.WriteLine(source);
}

在我使用上面代码的测试应用程序中，它产生了这个结果:

In my test app using the code above it produced this result:

看看我能写出的很酷的字母:?、? 和 ?！

找不到问号.使用 StreamReader 读取时是否设置了编码?

No question marks to be found. Are you setting the encoding when your reading it in with StreamReader?

您应该能够使用 Encoding.Convert 将 UTF-8 VCF 文件转换为 Windows-1252.不需要 Regex.Replace.这是我的做法:

You should just be able to use Encoding.Convert to convert the UTF-8 VCF file into Windows-1252. No need for Regex.Replace. Here is how I would do it:

// You might want to think of a better method name.
public string ConvertUTF8ToWin1252(string source)
{
    Encoding utf8 = new UTF8Encoding();
    Encoding win1252 = Encoding.GetEncoding(1252);

    byte[] input = source.ToUTF8ByteArray();  // Note the use of my extension method
    byte[] output = Encoding.Convert(utf8, win1252, input);

    return win1252.GetString(output);
}

这是我的扩展方法的外观:

And here is how my extension method looks:

public static class StringHelper
{
    // It should be noted that this method is expecting UTF-8 input only,
    // so you probably should give it a more fitting name.
    public static byte[] ToUTF8ByteArray(this string str)
    {
        Encoding encoding = new UTF8Encoding();
        return encoding.GetBytes(str);
    }
}

此外，您可能还想添加usings 到您的 ReadFile 和 WriteFile 方法.

Also you'll probably want to add usings to your ReadFile and WriteFile methods.