如何使用从 windows 表格 C# 的“comboboxA”中选择来更改“comboboxB”的项目来源

Question

Two Combo-Boxes are added to a Windows form dynamically through code. Now the based on the selection from the Combo-Box-A i want to change the item source of Combo-Box-B.

Here are some snippets

Adding combo boxes dynamically

 string[] comboboxAitemsource = { "1", "2", "3", "4"};
                        string[] itemsource_1 = { "11", "12", "13", "14"};
                        string[] itemsource_2 = { "21", "22", "23", "24"};
                        string[] itemsource_3 = { "31", "32", "33", "34"};
                        string[] itemsource_4 = { "41", "42", "43", "44"};

                        int left_margin = 10, top_margin = margin, margin_inc = 40, sec_left_margin = 300;
                        System.Windows.Controls.Label ComboboxAlabel = new System.Windows.Controls.ComboboxAlabel();
                        ComboboxAlabel.HorizontalAlignment = System.Windows.HorizontalAlignment.Left; ;
                        ComboboxAlabel.VerticalAlignment = VerticalAlignment.Top;
                        ComboboxAlabel.Name = "typeComboboxAlabel";
                        ComboboxAlabel.Content = "COMBOBOX A";
                        ComboboxAlabel.Height = 40;
                        ComboboxAlabel.Margin = new Thickness((double)left_margin, (double)top_margin, (double)10, (double)0);
                        grid.Children.Add(ComboboxAlabel);


                        System.Windows.Controls.ComboBox comboboxA = new System.Windows.Controls.ComboBox();
                        comboboxA.HorizontalAlignment = System.Windows.HorizontalAlignment.Left; ;
                        comboboxA.VerticalAlignment = VerticalAlignment.Top;
                        comboboxA.Name = "typeCombobox";
                        comboboxA.Height = 20;
                        comboboxA.Width = 250;
                        comboboxA.Margin = new Thickness((double)sec_left_margin, (double)top_margin, (double)10, (double)0);
                        comboboxA.ItemsSource = comboboxAitemsource;
                        comboboxA.SelectedIndex = 0;
                        comboboxA.SelectionChanged += new System.Windows.Controls.SelectionChangedEventHandler(typeCombobox_SelectionChangedEventHandler);
                        top_margin = top_margin + margin_inc;
                        grid.Children.Add(comboboxA);
                       
                        System.Windows.Controls.Label comboboxBlabel = new System.Windows.Controls.Label();
                        comboboxBlabel.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
                        comboboxBlabel.VerticalAlignment = VerticalAlignment.Top;
                        comboboxBlabel.Name = "typeLabelUpdate";
                        comboboxBlabel.Content = "COMBOBOX B";
                        comboboxBlabel.Height = 40;
                        comboboxBlabel.Margin = new Thickness((double)left_margin, (double)top_margin, (double)10, (double)0);
                        grid.Children.Add(comboboxBlabel);

                        System.Windows.Controls.ComboBox comboboxB = new System.Windows.Controls.ComboBox();
                        comboboxB.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
                        comboboxB.VerticalAlignment = VerticalAlignment.Top;
                        comboboxB.Name = "typeComboBoxUpdate";
                        comboboxB.Height = 20;
                        comboboxB.Width = 250;
                        comboboxB.Margin = new Thickness((double)sec_left_margin, (double)top_margin, (double)10, (double)0);
                        comboboxB.ItemsSource = itemsource_1;
                        comboboxB.SelectedIndex = 0;
                        top_margin = top_margin + margin_inc;
                        grid.Children.Add(comboboxB);

Event handler for combo box A

private void typeCombobox_SelectionChangedEventHandler(object sender, EventArgs e)
        {
            ComboBox comboBox = (ComboBox)sender;
            
        }

By default item source for combo box B is itemsource_1, but when the selection changes on combo box A the item source of combo box b should change based on the selection.

for example if selection of combo box A changes to 4 the item source of combo box B should change to itemsource_4.

I have added a event handler but I'm unable to access the combo box b in the event handler. Any help would be really appreciated..

Answer 1

i think:

private void comboxa_SelectedIndexChanged(object sender, EventArgs e)
        {
             comboxb.Items.Clear();
             comboxb.Items.AddRange(itemsource_1);

        }

Answer 2

 private void d()
        {
            string[] comboboxAitemsource = { "1", "2", "3", "4" };
            string[] itemsource_1 = { "11", "12", "13", "14" };
            string[] itemsource_2 = { "21", "22", "23", "24" };
            string[] itemsource_3 = { "31", "32", "33", "34" };
            string[] itemsource_4 = { "41", "42", "43", "44" };

            int left_margin = 10, top_margin = margin, margin_inc = 40, sec_left_margin = 300;
            System.Windows.Controls.Label ComboboxAlabel = new System.Windows.Controls.ComboboxAlabel();
            ComboboxAlabel.HorizontalAlignment = System.Windows.HorizontalAlignment.Left; ;
            ComboboxAlabel.VerticalAlignment = VerticalAlignment.Top;
            ComboboxAlabel.Name = "typeComboboxAlabel";
            ComboboxAlabel.Content = "COMBOBOX A";
            ComboboxAlabel.Height = 40;
            ComboboxAlabel.Margin = new Thickness((double)left_margin, (double)top_margin, (double)10, (double)0);
            grid.Children.Add(ComboboxAlabel);


            System.Windows.Controls.ComboBox comboboxA = new System.Windows.Controls.ComboBox();
            comboboxA.HorizontalAlignment = System.Windows.HorizontalAlignment.Left; ;
            comboboxA.VerticalAlignment = VerticalAlignment.Top;
            comboboxA.Name = "typeCombobox";
            comboboxA.Height = 20;
            comboboxA.Width = 250;
            comboboxA.Margin = new Thickness((double)sec_left_margin, (double)top_margin, (double)10, (double)0);
            comboboxA.ItemsSource = comboboxAitemsource;
            comboboxA.SelectedIndex = 0;
            comboboxA.SelectionChanged += new System.Windows.Controls.SelectionChangedEventHandler(typeCombobox_SelectionChangedEventHandler);
            top_margin = top_margin + margin_inc;
            grid.Children.Add(comboboxA);

            System.Windows.Controls.Label comboboxBlabel = new System.Windows.Controls.Label();
            comboboxBlabel.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
            comboboxBlabel.VerticalAlignment = VerticalAlignment.Top;
            comboboxBlabel.Name = "typeLabelUpdate";
            comboboxBlabel.Content = "COMBOBOX B";
            comboboxBlabel.Height = 40;
            comboboxBlabel.Margin = new Thickness((double)left_margin, (double)top_margin, (double)10, (double)0);
            grid.Children.Add(comboboxBlabel);

            System.Windows.Controls.ComboBox comboboxB = new System.Windows.Controls.ComboBox();
            comboboxB.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
            comboboxB.VerticalAlignment = VerticalAlignment.Top;
            comboboxB.Name = "typeComboBoxUpdate";
            comboboxB.Height = 20;
            comboboxB.Width = 250;
            comboboxB.Margin = new Thickness((double)sec_left_margin, (double)top_margin, (double)10, (double)0);
            comboboxB.ItemsSource = itemsource_1;
            comboboxB.SelectedIndex = 0;
            top_margin = top_margin + margin_inc;
            grid.Children.Add(comboboxB);

            comboboxA.SelectedIndexChanged += (s, e) => {
                comboboxB.Items.Clear();
                comboboxB.Items.AddRange(itemsource_1);
            };

        }