有条件地添加带有条件项列表的组合框

Question

我正在制作一个Windows窗体，其中每次在组合框中选择一个项目时，都会将另一个组合框动态添加到该窗体中。这工作得很好，但是我的问题是，我希望组合框的所选项目不出现在其他任何项目中。所有组合框都从数组comborange中提取，因此我将基于该索引删除项目。

我的代码几乎可以工作，但是变得非常复杂，所以我知道必须有一种更简单的方法。而且，通过几乎可行的方式，我的意思是添加第一个组合框后，它无法完美运行。

我还应该注意，这都是有条件的，基于复选框，搜索栏也有条件地出现，但是这些与该问题不是特别相关。

private void checkBox1_CheckedChanged(object sender, EventArgs e)
    {
        // Determine the CheckState of the check box.  
        if (checkBox1.CheckState == CheckState.Checked)
        {
            // Add second combobox to first groupbox if this is checked
            groupBox1.Controls.Add(combo);
            //combo.Items.AddRange(comborange);
            combo.Location = new System.Drawing.Point(19, 123);
            combo.Name = "combo";
            combo.Size = new System.Drawing.Size(121, 21);
            combo.TabIndex = 0;
            combo.SelectedIndexChanged += new System.EventHandler(this.combo_SelectedIndexChanged);
            combo.BringToFront();

            this.AllowDrop = false;
        }
        if (checkBox1.CheckState == CheckState.Unchecked)
        {
            // Remove combobox from groupbox if this is unchecked
            groupBox1.Controls.Remove(combo);
            Controls.Remove(combo);
            combo.Items.Clear();

            // Remove search bars other than main one
            // Remove first search bar and button
            groupBox3.Controls.Remove(search2);
            Controls.Remove(search2);
            groupBox3.Controls.Remove(sbutton1);
            Controls.Remove(sbutton1);
        }
    }

    private void checkBox1_Click(object sender, System.EventArgs e)
    {
        switch (checkBox1.CheckState)
        {
            case CheckState.Checked:
                // Add second combo box if this is checked
                ComboBox combo = new ComboBox();
                Controls.Add(combo);
                break;
            case CheckState.Unchecked:

                break;
            case CheckState.Indeterminate:

                break;
        }
    }

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        // Clear second combo box if the selection is changed
        var combocount = combo.Items.Count;
        string combobox1str = (string) comboBox1.SelectedItem;
        if (combocount < comborange.Length)
        {
            combo.Items.Clear();
            combo.Items.AddRange(comborange);
            combo2.Items.Clear();
            combo2.Items.AddRange(comborange);
        }
        int currentcomboBox1Index = comboBox1.SelectedIndex;
        combo.Items.RemoveAt(currentcomboBox1Index);

        // Add text box
        TextBox search1 = new TextBox();
        groupBox3.Controls.Add(search1);
        Controls.Add(search1);
        search1.Location = new System.Drawing.Point(519, 137);
        search1.Size = new System.Drawing.Size(323, 21);
        search1.Text = combobox1str;
        search1.AcceptsReturn = false;
        search1.AcceptsTab = false;
        search1.BringToFront();

        // Add search button
        Button sbutton1 = new Button();
        groupBox3.Controls.Add(sbutton1);
        Controls.Add(sbutton1);
        sbutton1.Location = new System.Drawing.Point(850, 137);
        sbutton1.Size = new System.Drawing.Size(63, 21);
        sbutton1.Text = "Search";
        sbutton1.BringToFront();


    }
    private void combo_SelectedIndexChanged(object sender, EventArgs e)
    {
        string combostr = (string)combo.SelectedItem;

        // Add text box
        TextBox search1 = new TextBox();
        groupBox3.Controls.Add(search2);
        Controls.Add(search2);
        search2.Location = new System.Drawing.Point(519, 187);
        search2.Size = new System.Drawing.Size(323, 21);
        search2.Text = combostr;
        search2.AcceptsReturn = false;
        search2.AcceptsTab = false;
        search2.BringToFront();

        // Add search button
        Button sbutton1 = new Button();
        groupBox3.Controls.Add(sbutton2);
        Controls.Add(sbutton2);
        sbutton2.Location = new System.Drawing.Point(850, 187);
        sbutton2.Size = new System.Drawing.Size(63, 21);
        sbutton2.Text = "Search";
        sbutton2.BringToFront();

        // Add next combobox
        ComboBox combo2 = new ComboBox();
        Controls.Add(combo2);
        groupBox1.Controls.Add(combo2);
        combo2.Location = new System.Drawing.Point(19, 173);
        combo2.Name = "combo2";
        combo2.Size = new System.Drawing.Size(121, 21);
        combo2.TabIndex = 0;
        combo2.SelectedIndexChanged += new System.EventHandler(this.combo2_SelectedIndexChanged);
        combo2.BringToFront();

        this.AllowDrop = false;

        // Clear second combo box if the selection is changed
        var combo2count = combo2.Items.Count;
        if (combo2count < comborange.Length)
        {
            combo2.Items.Clear();
            combo2.Items.AddRange(comborange);
        }
        int currentcomboIndex = combo.SelectedIndex;
        combo2.Items.RemoveAt(currentcomboIndex);
        combo2.Items.RemoveAt(currentcomboBox1Index + 1);

    }

    private void combo2_SelectedIndexChanged(object sender, EventArgs e)
    {

    }