C# 如何使用长度来切分字符串

参考网址：https://blog.csdn.net/yenange/article/details/39637211

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Data;  

    namespace Study
    {
        public static class Program2
        {
            static void Main(string[] args)
            {
                string[] source = {
                    null,
                    string.Empty,
                    "",
                    "",
                    "",
                    "",
                };
                int charNum = ;
                int i = ;
                foreach (string str in source)
                {
                    Console.WriteLine("原字符串{0}：{1}", (i++).ToString(), str);
                    string[] r = str.SplitByLen(charNum, "{0}/{1}){2}");
                    foreach (string s in r)
                    {
                        Console.WriteLine("{0}", s);
                    }
                    Console.WriteLine();
                }
                Console.Read();
            }  

            /// <returns></returns>
            /// <summary>
            /// 按字符串长度切分成数组
            /// </summary>
            /// <param name="str">原字符串</param>
            /// <param name="separatorCharNum">切分长度</param>
            /// <param name="prefixFormat">前缀格式</param>
            /// <returns>字符串数组</returns>
            public static string[] SplitByLen(this string str, int separatorCharNum, string prefixFormat)
            {
                string[] arr = SplitByLen(str, separatorCharNum);
                if (arr.Length == )
                {
                    return arr;
                }
                List<string> list = new List<string>();
                for(int i=;i<=arr.Length;i++)
                {
                    list.Add(string.Format(prefixFormat,i.ToString(), arr.Length.ToString(), arr[i-]));
                }
                return list.ToArray();
            }  

            /// <summary>
            /// 按字符串长度切分成数组
            /// </summary>
            /// <param name="str">原字符串</param>
            /// <param name="separatorCharNum">切分长度</param>
            /// <returns>字符串数组</returns>
            public static string[] SplitByLen(this string str, int separatorCharNum)
            {
                if (string.IsNullOrEmpty(str) || str.Length <= separatorCharNum)
                {
                    return new string[] { str };
                }
                string tempStr = str;
                List<string> strList = new List<string>();
                int iMax = Convert.ToInt32(Math.Ceiling(str.Length / (separatorCharNum * 1.0)));//获取循环次数
                for (int i = ; i <= iMax; i++)
                {
                    string currMsg = tempStr.Substring(, tempStr.Length > separatorCharNum ? separatorCharNum : tempStr.Length);
                    strList.Add(currMsg);
                    if (tempStr.Length > separatorCharNum)
                    {
                        tempStr = tempStr.Substring(separatorCharNum, tempStr.Length - separatorCharNum);
                    }
                }
                return strList.ToArray();
            }
        }
    }  

自己参考的一个简单历程：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ChaiF
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
           string[] arr=SplitByLen(textBox1.Text,);
            textBox2.Text=arr[].ToString();
            textBox3.Text=arr[].ToString();

        }
        public string[] SplitByLen(string str, int separatorCharNum)
        {
            if (string.IsNullOrEmpty(str) || str.Length <= separatorCharNum)
            {
                return new string[] { str };
            }
            string tempStr = str;
            List<string> strList = new List<string>();
            int iMax = Convert.ToInt32(Math.Ceiling(str.Length / (separatorCharNum * 1.0)));//获取循环次数
            for (int i = ; i <= iMax; i++)
            {
                string currMsg = tempStr.Substring(, tempStr.Length > separatorCharNum ? separatorCharNum : tempStr.Length);
                strList.Add(currMsg);
                if (tempStr.Length > separatorCharNum)
                {
                    tempStr = tempStr.Substring(separatorCharNum, tempStr.Length - separatorCharNum);
                }
            }
            return strList.ToArray();
        }
    }
}