自定义替换json编码不按预期输出双引号 [英] Custom replace for json encoding not outputting double quotes as expected

问题描述

创建了自己的json编码器后，我意识到它用两个转义的反斜杠代替了双引号，而不是一个。

After I created my own json encoder, I realized it was replacing double-quotes with two escaping backslashes instead of one.

我意识到，现在，C＃具有一个内置的 Json.Encode（）方法，是的，我已经开始使用它了，但是，为什么下面的代码（我使用的json编码器）让我感到困惑

I realize, now, that C# has a built in Json.Encode() method, and yes, I have gotten it to work, however, I am left baffled by why the following code (the json encoder I had built) didn't replace quotes as I would expect.

这是我的json编码器方法：

Here is my json encoder method:

public static string jsonEncode(string val)
{
    val = val.Replace("\r\n", " ")
             .Replace("\r", " ")
             .Replace("\n", " ")
             .Replace("\"", "\\\"")
             .Replace("\\", "\\\\");

    return val;
}

替换调用： Replace（ \ ， \\\）将 替换为 \\ ，它当然会生成无效的json，因为它在json文件中将两个反斜杠（一个作为转义字符，类似于上面的C＃）视为单个真实反斜杠，因此不会转义双引号， 如预期。 Replace（ \\， \）调用可以完美地工作，但是（即，它将一个反斜杠替换为两个反斜杠，因为

The replace call: Replace("\"", "\\\"") is replacing " with \\", which of course produces invalid json, as it sees the two backslashes (one as an escape character, much like the above C#) as a single 'real' backslash in the json file, thus not escaping the double-quote, as intended. The Replace("\\", "\\\\") call works perfectly, however (i.e., it replaces one backslash with two, as I would expect).

根据我的论据，我很容易说出Replace方法没有执行功能，就像我期望的那样。我的问题是为什么？我知道我不能使用 Replace（ \， \\），因为反斜杠也是C＃的转义字符，因此它将产生语法错误。使用 Replace（ \， \）也是很愚蠢的，因为它将用双引号替换双引号。

It is easy for me to tell that the Replace method is not performing the functions, based on my arguments, like I would expect. My question is why? I know I can't use Replace("\"", "\\"") as the backslash is also an escape character for C#, so it will produce a syntax error. Using Replace("\"", "\"") would also be silly, as it would replace a double-quote with a double-quote.

为了更好地理解C＃中的replace方法，我想知道为什么Replace方法的行为与我预期的不同。 Json.Encode 如何实现此级别的编码？

For better understanding of the replace method in C#, I would love to know why the Replace method is behaving differently than I'd expect. How does Json.Encode achieve this level of coding?

推荐答案

您将 替换为 \ ，然后 then 用两个反斜杠替换任何反斜杠。 ..其中将包含您已经创建的反斜杠。一次在纸上执行一次操作，您将看到相同的效果。

You're replacing " with \" and then replacing any backslashes with two backslashes... which will include the backslash you've already created. Perform the operations one at a time on paper and you'll see the same effect.

所有您需要做的就是颠倒转义的顺序，以便逃脱先反斜杠，然后然后引用：

All you need to do is reverse the ordering of the escaping, so that you escape backslashes first and then quotes:

return val.Replace("\r\n", " ")
          .Replace("\r", " ")
          .Replace("\n", " ")
          .Replace("\\", "\\\\")
          .Replace("\"", "\\\"");

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