Csharp 从 C# 中的字符串开头修剪所有可能的空白字符和自定义字符的最佳方法是什么

看起来没有简单的方法，因为string.Trim()内部使用两种不同的方法.

用于空格的TrimWhiteSpaceHelper:

    private string TrimWhiteSpaceHelper(TrimType trimType)
    {
        // end will point to the first non-trimmed character on the right.
        // start will point to the first non-trimmed character on the left.
        int end = Length - 1;
        int start = 0;

        // Trim specified characters.
        if ((trimType & TrimType.Head) != 0)
        {
            for (start = 0; start < Length; start++)
            {
                if (!char.IsWhiteSpace(this[start]))
                {
                    break;
                }
            }
        }

        if ((trimType & TrimType.Tail) != 0)
        {
            for (end = Length - 1; end >= start; end--)
            {
                if (!char.IsWhiteSpace(this[end]))
                {
                    break;
                }
            }
        }

        return CreateTrimmedString(start, end);
    }

和用于自定义字符的TrimHelper:

private unsafe string TrimHelper(char* trimChars, int trimCharsLength, TrimType trimType)
    {
        Debug.Assert(trimChars != null);
        Debug.Assert(trimCharsLength > 0);

        // end will point to the first non-trimmed character on the right.
        // start will point to the first non-trimmed character on the left.
        int end = Length - 1;
        int start = 0;

        // Trim specified characters.
        if ((trimType & TrimType.Head) != 0)
        {
            for (start = 0; start < Length; start++)
            {
                int i = 0;
                char ch = this[start];
                for (i = 0; i < trimCharsLength; i++)
                {
                    if (trimChars[i] == ch)
                    {
                        break;
                    }
                }
                if (i == trimCharsLength)
                {
                    // The character is not in trimChars, so stop trimming.
                    break;
                }
            }
        }

        if ((trimType & TrimType.Tail) != 0)
        {
            for (end = Length - 1; end >= start; end--)
            {
                int i = 0;
                char ch = this[end];
                for (i = 0; i < trimCharsLength; i++)
                {
                    if (trimChars[i] == ch)
                    {
                        break;
                    }
                }
                if (i == trimCharsLength)
                {
                    // The character is not in trimChars, so stop trimming.
                    break;
                }
            }
        }

        return CreateTrimmedString(start, end);
    }

将它们组合在一起可能看起来像这样:

public static class TrimmerExtension
{
    public static string TrimWhitespaceAndPrefixes(this string str, params char[] trimChars)
    {
        var trimCharsLength = trimChars.Length;
        int start;
        for (start = 0; start < str.Length; start++)
        {
            var ch = str[start];
            if (!char.IsWhiteSpace(ch))
            {
                int i;
                for (i = 0; i < trimCharsLength; i++)
                {
                    if (trimChars[i] == ch)
                    {
                        break;
                    }
                }

                if (i == trimCharsLength)
                {
                    break;
                }
            }
        }

        return str[start..];
    }
}

如果性能不是很重要，我建议使用正则表达式或从https://stackoverflow.com/a/76133168/2770274开始的速记版本