C# 动态添加ComboBox遇到的问题

问题遇到的现象和发生背景

点击按钮，添加三个ComboBox和一个TextBox。添加完成后，如图所示，修改其中一个ComboBox以后，会导致另外几个新创建的ComboBox也会跟着修改，TextBox没有这个问题，主要是ComboBox有这个问题

问题相关代码，请勿粘贴截图

public void button_Add_Click(object sender, EventArgs e)
        {
            //创建新的荷载工况和加载方式的ComboBox和荷载值的TextBox
            num_ClickButtonAdd++;

            ComboBox comboBox_LoadCase_Add = new ComboBox();
            ComboBox comboBox_LoadType_Add = new ComboBox();
            ComboBox comboBox_Dir_Add = new ComboBox();
            TextBox textBox_LoadNum_Add = new TextBox();

            comboBox_LoadCase_Add.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            comboBox_LoadCase_Add.Font = new System.Drawing.Font("宋体", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
            comboBox_LoadCase_Add.FormattingEnabled = true;
            comboBox_LoadCase_Add.Location = new System.Drawing.Point(8, (int)comboBox_LoadCase0.Tag + num_ClickButtonAdd * 40);
            comboBox_LoadCase_Add.Name = "comboBox_LoadCase" + num_ClickButtonAdd.ToString();
            comboBox_LoadCase_Add.Size = new System.Drawing.Size(100, 28);
            comboBox_LoadCase_Add.Tag = comboBox_LoadCase_Add.Location.Y;
            this.panel_LoadInfo.Controls.Add(comboBox_LoadCase_Add);
            comboBox_LoadCase_Add.DataSource = comboBox_LoadCase0.Items;
            comboBox_LoadCase_Add.SelectedIndex = 0;

            comboBox_LoadType_Add.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            comboBox_LoadType_Add.Font = new System.Drawing.Font("宋体", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
            comboBox_LoadType_Add.FormattingEnabled = true;
            comboBox_LoadType_Add.Location = new System.Drawing.Point(114, (int)comboBox_LoadType0.Tag + num_ClickButtonAdd * 40);
            comboBox_LoadType_Add.Name = "comboBox_LoadType" + num_ClickButtonAdd.ToString();
            comboBox_LoadType_Add.Size = new System.Drawing.Size(140, 28);
            comboBox_LoadType_Add.Tag = comboBox_LoadType_Add.Location.Y;
            this.panel_LoadInfo.Controls.Add(comboBox_LoadType_Add);
            comboBox_LoadType_Add.DataSource = comboBox_LoadType0.Items;
            comboBox_LoadType_Add.SelectedIndex = 0;

            comboBox_Dir_Add.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            comboBox_Dir_Add.Font = new System.Drawing.Font("宋体", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
            comboBox_Dir_Add.FormattingEnabled = true;
            comboBox_Dir_Add.Location = new System.Drawing.Point(260, (int)comboBox_Dir0.Tag + num_ClickButtonAdd * 40);
            comboBox_Dir_Add.Name = "comboBox_Dir" + num_ClickButtonAdd.ToString();
            comboBox_Dir_Add.Size = new System.Drawing.Size(130, 28);
            comboBox_Dir_Add.Tag = comboBox_Dir_Add.Location.Y;
            this.panel_LoadInfo.Controls.Add(comboBox_Dir_Add);
            comboBox_Dir_Add.DataSource = comboBox_Dir0.Items;
            comboBox_Dir_Add.SelectedIndex = 5;

            textBox_LoadNum_Add.Location = new System.Drawing.Point(396, (int)textBox_LoadNum0.Tag + num_ClickButtonAdd * 40);
            textBox_LoadNum_Add.Name = "textBox_LoadNum" + num_ClickButtonAdd.ToString();
            textBox_LoadNum_Add.Size = new System.Drawing.Size(80, 30);
            textBox_LoadNum_Add.Tag = textBox_LoadNum_Add.Location.Y;
            textBox_LoadNum_Add.Text = "0";
            this.panel_LoadInfo.Controls.Add(textBox_LoadNum_Add);
        }

运行结果及报错内容

我想要达到的结果

我想要的结果就是新添加的几个ComboBox能够不互相影响

comboBox_LoadCase_Add.DataSource = comboBox_LoadCase0.Items;
comboBox_LoadType_Add.DataSource = comboBox_LoadType0.Items;
comboBox_Dir_Add.DataSource = comboBox_Dir0.Items;
你多个控件绑定同一个数据源后就会有这种问题，解决方案是：

1. 用循环将数据源里的数据一个个取出来后，再combobox.items.add添加到目标控件中
2. 将源数据copy出来，再给到每个combobox，比如
   DataTable tableSource ;
   ComboBox1.DataSource=tableSource.Copy();

从你添加的代码来看，没问题。三个combobox都是创建的新实例，数据源也都不一样。要看看你修改的代码，是不是把所有combobox的数据源都改了。贴你修改代码看看