要拆分字符串，您需要使用采用字符串数组的重载:

To split on a string you need to use the overload that takes an array of strings:

string[] lines = theText.Split(
    new string[] { Environment.NewLine },
    StringSplitOptions.None
);

如果要处理文本中不同类型的换行符，可以使用匹配多个字符串的功能.这将在任一类型的换行符上正确拆分，并在文本中保留空行和间距:

If you want to handle different types of line breaks in a text, you can use the ability to match more than one string. This will correctly split on either type of line break, and preserve empty lines and spacing in the text:

string[] lines = theText.Split(
    new string[] { "
", "
", "
" },
    StringSplitOptions.None
);