C#中等号左右的文本值交换

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 Change
{
    public partial class FrmChange : Form
    {
        public FrmChange()
        {
            InitializeComponent();
        }

        private void btnChange_Click(object sender, EventArgs e)
        {
            //获取到第一个文本框的文本内容
            string top = txtTop.Text.Trim();
            //判断第一个文本框里面是否有=号
            int count1 = top.Count(c1=>c1=='=');
            //判断第一个文本框里面是否有分号
            int count2 = top.Count(c2=>c2==';');
            //返回包含此字符串string的数组,以分号分割,
            string[] arr1 = top.Split(';');
            string[] arr2=new string[arr1.Length];
            if (count1 > 0 && count2 > 0)
            {
                //截取每个分号前的字符串
                for (int i = 0; i < arr1.Length - 1; i++)
                {
                    //获取分号存在的下标
                    int index = top.IndexOf(";");
                    //获取每个分号的字符串
                    string fh = top.Substring(0, index);
                    arr2[i] = fh;
                    top = top.Substring(index + 1);
                }

                for (int i = 0; i < arr2.Length - 1; i++)
                {
                    string txt = arr2[i].Trim();
                    //获取=号存在的下标
                    int index = txt.IndexOf("=");
                    //获取=号左边的字符串
                    string left = txt.Substring(0, index);
                    //获取=号右边的字符串
                    string right = txt.Substring(index + 1);
                    arr2[i] = right + "=" + left;
                    MessageBox.Show(arr2[i], "提示");
                }

                //遍历arr2数组 并且给下面的文本框赋值
                for (int i = 0; i < arr2.Length - 1; i++)
                {
                    txtDown.Text += arr2[i] + ";\r\n";
                }
            }else {
                MessageBox.Show("文本框中未输入分号或者等号","女神提示");
            }

        }
    }
}

代码运行图:

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