winform -tab选项切换dropdownlist值不变

namespace WindowsApplication1
{
    partial class Form14
    {
        /// <summary>
        /// 必要なデザイナ変数です。
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// 使用中のリソースをすべてクリーンアップします。
        /// </summary>
        /// <param name="disposing">マネージ リソースが破棄される場合 true、破棄されない場合は false です。</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows フォーム デザイナで生成されたコード

        /// <summary>
        /// デザイナ サポートに必要なメソッドです。このメソッドの内容を
        /// コード エディタで変更しないでください。
        /// </summary>
        private void InitializeComponent()
        {
            this.comboBox1 = new System.Windows.Forms.ComboBox();
            this.comboBox2 = new System.Windows.Forms.ComboBox();
            this.tabControl1 = new System.Windows.Forms.TabControl();
            this.tabPage1 = new System.Windows.Forms.TabPage();
            this.tabPage2 = new System.Windows.Forms.TabPage();
            this.button1 = new System.Windows.Forms.Button();
            this.tabControl1.SuspendLayout();
            this.tabPage1.SuspendLayout();
            this.tabPage2.SuspendLayout();
            this.SuspendLayout();
            //
            // comboBox1
            //
            this.comboBox1.FormattingEnabled = true;
            this.comboBox1.Items.AddRange(new object[] {
            "11111111",
            "22222222",
            "33333333"});
            this.comboBox1.Location = new System.Drawing.Point(3, 6);
            this.comboBox1.Name = "comboBox1";
            this.comboBox1.Size = new System.Drawing.Size(121, 20);
            this.comboBox1.TabIndex = 0;
            this.comboBox1.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);
            //
            // comboBox2
            //
            this.comboBox2.FormattingEnabled = true;
            this.comboBox2.Items.AddRange(new object[] {
            "555555",
            "666666",
            "777777"});
            this.comboBox2.Location = new System.Drawing.Point(3, 6);
            this.comboBox2.Name = "comboBox2";
            this.comboBox2.Size = new System.Drawing.Size(121, 20);
            this.comboBox2.TabIndex = 1;
            this.comboBox2.SelectedIndexChanged += new System.EventHandler(this.comboBox2_SelectedIndexChanged);
            //
            // tabControl1
            //
            this.tabControl1.Controls.Add(this.tabPage1);
            this.tabControl1.Controls.Add(this.tabPage2);
            this.tabControl1.Location = new System.Drawing.Point(258, 112);
            this.tabControl1.Name = "tabControl1";
            this.tabControl1.SelectedIndex = 0;
            this.tabControl1.Size = new System.Drawing.Size(186, 108);
            this.tabControl1.TabIndex = 2;
            this.tabControl1.Click += new System.EventHandler(this.tabControl1_Click);
            //
            // tabPage1
            //
            this.tabPage1.Controls.Add(this.comboBox1);
            this.tabPage1.Location = new System.Drawing.Point(4, 22);
            this.tabPage1.Name = "tabPage1";
            this.tabPage1.Padding = new System.Windows.Forms.Padding(3);
            this.tabPage1.Size = new System.Drawing.Size(178, 82);
            this.tabPage1.TabIndex = 0;
            this.tabPage1.Text = "tabPage1";
            this.tabPage1.UseVisualStyleBackColor = true;
            //
            // tabPage2
            //
            this.tabPage2.Controls.Add(this.comboBox2);
            this.tabPage2.Location = new System.Drawing.Point(4, 22);
            this.tabPage2.Name = "tabPage2";
            this.tabPage2.Padding = new System.Windows.Forms.Padding(3);
            this.tabPage2.Size = new System.Drawing.Size(178, 82);
            this.tabPage2.TabIndex = 1;
            this.tabPage2.Text = "tabPage2";
            this.tabPage2.UseVisualStyleBackColor = true;
    
            // Form14
            //
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(501, 356);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.tabControl1);
            this.Name = "Form14";
            this.Text = "Form14";
            this.tabControl1.ResumeLayout(false);
            this.tabPage1.ResumeLayout(false);
            this.tabPage2.ResumeLayout(false);
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.ComboBox comboBox1;
        private System.Windows.Forms.ComboBox comboBox2;
        private System.Windows.Forms.TabControl tabControl1;
        private System.Windows.Forms.TabPage tabPage1;
        private System.Windows.Forms.TabPage tabPage2;
        private System.Windows.Forms.Button button1;
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Microsoft.VisualBasic;

namespace WindowsApplication1
{
    public partial class Form14 : Form
    {
        public Form14()
        {
            InitializeComponent();
        }
        private bool bo1 ;
        private bool bo2;
        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            bo2 = true;
        }
        private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
        {
            bo1= true;
        }
        private void tabControl1_Click(object sender, EventArgs e)
        {
            switch (tabControl1.SelectedTab.Name)
            {
                case"tabPage1":
                   if (bo1)
                    {
                        comboBox1.Enabled = false;
                    }
                    else
                    {
                        comboBox1.Enabled = true;
                        bo2 = false;
                        comboBox2.SelectedIndex = -1;
                    }
                    break;
                case "tabPage2":
                    if (bo2)
                    {
                        comboBox2.Enabled = false;
                    }
                    else
                    {
                        comboBox2.Enabled = true;
                        bo1 = false;
                        comboBox1.SelectedIndex = -1;
                    }
                    break;
            }
        }
    }
}

comboBox 自动左边加输入的数值

private void comboBox1_Leave(object sender, EventArgs e)
        {
            string aa = comboBox1.Text;
            this.textBox2.Text = aa.Split('|')[1];

            comboBox1.Text = aa.Split('|')[0];
        }