如何按字符数拆分字符串并在每个字符串的开头添加自定义字符串

Question

For example I have some string, length of this string = 2900 How can I divide this string by parts(length 255) and add for each part "Part {number}" + dividing string

On input: string (2900 length) Output: List with 12 element and each element should be = Part {number} + substring and length less than 255

I try smth like that, but I have trouble when I have more than 9 part

public static IEnumerable<string> SplitJobComment(string str, int chunkLength)
        {
            var partNumber = 1;
            var partNumberTemplate = $"Part {partNumber} ";
            chunkLength -= partNumberTemplate.Length;

            for (var i = 0; i < str.Length; i += chunkLength)
            {
                if (chunkLength + i > str.Length)
                {
                    chunkLength = str.Length - i;
                }

                partNumberTemplate = $"Part {partNumber} ";
                partNumber++;

                yield return partNumberTemplate + str.Substring(i, chunkLength);
            }
        }

Answer 1

Given that the real problem, as I assumed, is the fact that partNumberTemplate's length changes when partNumber>9, one possibile solution can be

var partNumberTemplate = $"Part {partNumber:D2} ";

{partNumber:D2} formats the number using always 2 digits.