Multi Select Combobox in WPF

Introduction:

Recently, in our project we wanted to allow the user to select multiple values in a list. But the list should be populated inside a grid row. So we don't want to use a listbox and also we are not interested in third-party tools. Instead of that, we wanted to use a multiselect combobox. When I browsed through various blogs, forums, etc. I got some good code, but none of them are easy for me to understand and implement so I decided to move with something bit tricky but easy for you. In short, below you will find a MultiSelect Combobox with Search feature on elements.

Using the code:

In the the below screen shots you will see I used a Listbox control to demonstrate the selected elements in Multiselect ComboBox.

main

In the below image you will see how the search feature is working; it doesn’t affect the selected elements but will manage the display of the elements; when search text was removed all Selected elements will come back into the List.

list

For better understanding I am going to split the article into two parts now :

  1. XML or designing Part
  2. C# part

To define the design part I used two controls, Dropdown for selection, and one Listbox just to display selected countries.

  1. <ComboBox Height="30" TextBoxBase.TextChanged="ddlCountry_TextChanged" HorizontalAlignment="Left" VerticalAlignment="Top" Name="ddlCountry" IsEditable="True" IsTextSearchEnabled="True" StaysOpenOnEdit="True" Width="165" SelectionChanged="ddlCountry_SelectionChanged" Margin="78,139,0,0">  
  2.     <ComboBox.ItemTemplate>  
  3.         <DataTemplate>  
  4.             <CheckBox Name="chkCountry" Width="220" Checked="AllCheckbocx_CheckedAndUnchecked" Unchecked="AllCheckbocx_CheckedAndUnchecked" Content="{Binding Country_Name}" IsChecked="{Binding Check_Status}" CommandParameter="{Binding Country_ID}">  
  5.             </CheckBox>  
  6.         </DataTemplate>  
  7.     </ComboBox.ItemTemplate>  
  8. </ComboBox>  
  9.   
  10. <ListBox Name="testListbox" HorizontalAlignment="Left" Height="161" Margin="370,80,0,0" VerticalAlignment="Top" Width="100" /> 
To Bind the Multiselect Combobox ddlCountry I created a class with three properties. In the the Check_Status is basically used to identify selected items.
  1. public class DDL_Country  
  2. {  
  3.     public int Country_ID   
  4.   {  
  5.         get;  
  6.         set;  
  7.     }  
  8.     public string Country_Name   
  9.     {  
  10.         get;  
  11.         set;  
  12.     }  
  13.     public Boolean Check_Status   
  14.     {  
  15.         get;  
  16.         set;  
  17.     }  
  18. }  
To Bind country list in Dropdown I created one method.
  1. private void AddElementsInList()  
  2. {  
  3.     // 1 element  
  4.     DDL_Country obj = new DDL_Country();  
  5.     obj.Country_ID = 10;  
  6.     obj.Country_Name = "India";  
  7.     objCountryList.Add(obj);  
  8.     obj = new DDL_Country();  
  9.     obj.Country_ID = 11;  
  10.     obj.Country_Name = "Pakistan";  
  11.     objCountryList.Add(obj);  
  12.     obj = new DDL_Country();  
  13.     obj.Country_ID = 12;  
  14.     obj.Country_Name = "America";  
  15.     objCountryList.Add(obj);  
  16.     obj = new DDL_Country();  
  17.     obj.Country_ID = 13;  
  18.     obj.Country_Name = "U.K";  
  19.     objCountryList.Add(obj);  
  20.     obj = new DDL_Country();  
  21.     obj.Country_ID = 14;  
  22.     obj.Country_Name = "Arab";  
  23.     objCountryList.Add(obj);  
  24. }  
Please Find below the whle CS page code.

 

  1. using System;  
  2. using System.Collections.Generic;  
  3. using System.Windows;  
  4. using System.Windows.Controls;  
  5. using System.Linq;  
  6.   
  7. namespace MultiSelectCombobox  
  8. {  
  9.     /// <summary>  
  10.     /// Interaction logic for MainWindow.xaml  
  11.     /// </summary>  
  12.     public partial class MainWindow: Window   
  13.     {  
  14.         List < DDL_Country > objCountryList;  
  15.   
  16.         public MainWindow()  
  17.         {  
  18.             InitializeComponent();  
  19.             objCountryList = new List < DDL_Country > ();  
  20.             AddElementsInList();  
  21.             BindCountryDropDown();  
  22.         }  
  23.   
  24.   
  25.         private void BindCountryDropDown()  
  26.         {  
  27.             ddlCountry.ItemsSource = objCountryList;  
  28.         }  
  29.         private void ddlCountry_SelectionChanged(object sender, SelectionChangedEventArgs e)  
  30.         {  
  31.   
  32.         }  
  33.   
  34.         private void ddlCountry_TextChanged(object sender, TextChangedEventArgs e)  
  35.         {  
  36.             ddlCountry.ItemsSource = objCountryList.Where(x => x.Country_Name.StartsWith(ddlCountry.Text.Trim()));  
  37.         }  
  38.   
  39.         private void AllCheckbocx_CheckedAndUnchecked(object sender, RoutedEventArgs e)  
  40.         {  
  41.             BindListBOX();  
  42.         }  
  43.   
  44.         private void BindListBOX()  
  45.         {  
  46.             testListbox.Items.Clear();  
  47.             foreach(var country in objCountryList)  
  48.             {  
  49.                 if (country.Check_Status == true)  
  50.                 {  
  51.                     testListbox.Items.Add(country.Country_Name);  
  52.                 }  
  53.             }  
  54.         }  
  55.   
  56.         private void AddElementsInList()   
  57.         {  
  58.             // 1 element  
  59.             DDL_Country obj = new DDL_Country();  
  60.             obj.Country_ID = 10;  
  61.             obj.Country_Name = "India";  
  62.             objCountryList.Add(obj);  
  63.             obj = new DDL_Country();  
  64.             obj.Country_ID = 11;  
  65.             obj.Country_Name = "Pakistan";  
  66.             objCountryList.Add(obj);  
  67.             obj = new DDL_Country();  
  68.             obj.Country_ID = 12;  
  69.             obj.Country_Name = "America";  
  70.             objCountryList.Add(obj);  
  71.             obj = new DDL_Country();  
  72.             obj.Country_ID = 13;  
  73.             obj.Country_Name = "U.K";  
  74.             objCountryList.Add(obj);  
  75.             obj = new DDL_Country();  
  76.             obj.Country_ID = 14;  
  77.             obj.Country_Name = "Arab";  
  78.             objCountryList.Add(obj);  
  79.         }  
  80.     }  
  81.   
  82.     public class DDL_Country  
  83.     {  
  84.         public int Country_ID   
  85.       {  
  86.             get;  
  87.             set;  
  88.         }  
  89.         public string Country_Name  
  90.         {  
  91.             get;  
  92.             set;  
  93.         }  
  94.         public Boolean Check_Status  
  95.         {  
  96.             get;  
  97.             set;  
  98.         }  
  99.     }  
  100. }  
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