在c# 11.0预览版中，你可以使用原始字符串字面值。

Raw string literals are a new format for string literals. Raw string literals can contain arbitrary text, including whitespace, new lines, embedded quotes, and other special characters without requiring escape sequences. A raw string literal starts with at least three double-quote (""") characters. It ends with the same number of double-quote characters. Typically, a raw string literal uses three double quotes on a single line to start the string, and three double quotes on a separate line to end the string.

string str = """
    "How to add double quotes"
    """;

一种间接的，但简单易懂的替代方法，在字符串的开头和结尾添加引号-

char quote = '"';

string modifiedString = quote + "Original String" + quote;

现在是c# 11

var string1 = """before "inside" after""";

var string2 = """ "How to add double quotes" """;

如果我理解你的问题，也许你可以试试这个:

string title = string.Format("<div>\"{0}\"</div>", "some text");

如果你想在HTML中添加双引号

echo "<p>Congratulations, &#8220;" . $variable . "&#8221;!</p>";

输出

Congratulations, "Mr John"!

在c# 11.0预览版中，你可以使用原始字符串字面值。

Raw string literals are a new format for string literals. Raw string literals can contain arbitrary text, including whitespace, new lines, embedded quotes, and other special characters without requiring escape sequences. A raw string literal starts with at least three double-quote (""") characters. It ends with the same number of double-quote characters. Typically, a raw string literal uses three double quotes on a single line to start the string, and three double quotes on a separate line to end the string.

string str = """
    "How to add double quotes"
    """;