DataGrid Ctrl + F and F3 functionality WPF MVVM

Question

I am building a WPF MVVM application.

I have a DataGrid, like so:

<DataGrid 
       Name=“Employees” 
       AutoGenerateColumns=“False”         
       CanUserAddRows=“False” 
       EnableColumnVirtualization=“True” 
       EnableRowVirtualization=“True” 
       ItemsSource={Binding EmployeesCollectionView} 
       SelectionUnit=“FullRow”        
       VirtualizingPanel.VirtualizationMode=“Recycling” /> 

I want to implement a Ctrl+F and F3 search (similar like the browser one).

What is the best way to implement that?

Answer 1

Hi Stashy,
try following demo (MVVM with Interactivity).

XAML Main Window:

<Window x:Class="Window097"  
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"  
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"  
        xmlns:local="clr-namespace:WpfApp1.WpfApp097"  
        xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"  
        mc:Ignorable="d"  
        Title="211103_StashyCode-7539" Height="450" Width="800">  
  <Window.DataContext>  
    <local:ViewModel/>  
  </Window.DataContext>  
  <StackPanel>  
    <DataGrid Name="Employees" Height="200"  
              AutoGenerateColumns="True"  
              CanUserAddRows="False"  
              EnableColumnVirtualization="True"   
              EnableRowVirtualization="True"  
              ItemsSource="{Binding EmployeesDataTable}"  
              SelectionUnit="CellOrRowHeader"  
              VirtualizingPanel.VirtualizationMode="Recycling">  
      <i:Interaction.Behaviors>  
        <local:DataGridBehavior/>  
      </i:Interaction.Behaviors>  
    </DataGrid>  
    <Label Content="{Binding Info}"/>  
  </StackPanel>  
</Window>  

and classes:

Imports System.Collections.ObjectModel  
Imports System.ComponentModel  
Imports System.Runtime.CompilerServices  
Imports System.Windows.Interactivity  
  
Namespace WpfApp097  
  Public Class ViewModel  
    Implements INotifyPropertyChanged  
  
    Public Sub New()  
      ' Load demo data '  
      For i = 1 To 10  
        col.Add(New Data With {.ID = i, .Name = $"Row {i}"})  
      Next  
      cvs.Source = col  
    End Sub  
  
    Private col As New ObservableCollection(Of Data)  
    Private cvs As New CollectionViewSource  
  
    Public ReadOnly Property EmployeesDataTable As ICollectionView  
      Get  
        Return cvs.View  
      End Get  
    End Property  
  
    Private _info As String  
    Public Property Info As String  
      Get  
        Return Me._info  
      End Get  
      Set(value As String)  
        Me._info = value  
        OnPropChanged()  
      End Set  
    End Property  
  
    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged  
    Private Sub OnPropChanged(<CallerMemberName> Optional propName As String = "")  
      RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propName))  
    End Sub  
  End Class  
  
  Public Class Data  
    Public Property ID As Integer  
    Public Property Name As String  
  End Class  
  
  Public Class DataGridBehavior  
    Inherits Behavior(Of DataGrid)  
    Protected Overrides Sub OnAttached()  
      AddHandler AssociatedObject.PreviewKeyDown, AddressOf OnPreviewKeyDown  
      AddHandler AssociatedObject.PreviewKeyUp, AddressOf OnPreviewKeyUp  
    End Sub  
  
    Private Sub OnPreviewKeyDown(sender As Object, e As KeyEventArgs)  
      If e.Key = Key.F3 Then  
        CType(AssociatedObject.DataContext, ViewModel).Info = "Pressed F3"  
      ElseIf e.Key = Key.LeftCtrl Then  
        LeftCtrl = True  
      ElseIf e.Key = Key.F Then  
        CType(AssociatedObject.DataContext, ViewModel).Info = "Pressed ctrl left + F"  
      End If  
    End Sub  
  
    Private Sub OnPreviewKeyUp(sender As Object, e As KeyEventArgs)  
      If e.Key = Key.LeftCtrl Then  
        LeftCtrl = False  
      End If  
    End Sub  
  
    Private LeftCtrl As Boolean = False  
  
  End Class  
  
End Namespace  

Result:

The same code in C#:

<Window x:Class="WpfApp1.Window079"  
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"  
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"  
        xmlns:local="clr-namespace:Wpf1App079"  
        xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"  
        mc:Ignorable="d"  
        Title="211103_StashyCode-7539" Height="450" Width="800">  
  <Window.DataContext>  
    <local:ViewModel/>  
  </Window.DataContext>  
  <StackPanel>  
    <DataGrid Name="Employees" Height="200"  
              AutoGenerateColumns="True"  
              CanUserAddRows="False"  
              EnableColumnVirtualization="True"   
              EnableRowVirtualization="True"  
              ItemsSource="{Binding EmployeesDataTable}"  
              SelectionUnit="CellOrRowHeader"  
              VirtualizingPanel.VirtualizationMode="Recycling">  
      <i:Interaction.Behaviors>  
        <local:DataGridBehavior/>  
      </i:Interaction.Behaviors>  
    </DataGrid>  
    <Label Content="{Binding Info}"/>  
  </StackPanel>  
</Window>  
  
  
using System.Collections.ObjectModel;  
using System.ComponentModel;  
using System.Runtime.CompilerServices;  
using System.Windows;  
using System.Windows.Controls;  
using System.Windows.Data;  
using System.Windows.Input;  
using System.Windows.Interactivity;  
  
namespace Wpf1App079  
{  
  public class ViewModel : INotifyPropertyChanged  
  {  
  
    public ViewModel()  
    {  
      // Load demo data  
      for (int i = 0; i < 10; i++) col.Add(new Data() { ID = i, Name = $"Row {i}" });  
      cvs.Source = col;  
    }  
  
    private CollectionViewSource cvs = new CollectionViewSource();  
    private ObservableCollection<Data> col = new ObservableCollection<Data>();  
  
    public ICollectionView EmployeesDataTable { get => cvs.View; }  
  
    private string _info;  
    public string Info  
    {  
      get => this._info;  
      set { this._info = value; OnPropertyChanged(); }  
    }  
  
    public event PropertyChangedEventHandler PropertyChanged;  
    private void OnPropertyChanged([CallerMemberName] string propName = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));  
  }  
  
  public class Data  
  {  
    public int ID { get; set; }  
    public string Name { get; set; }  
  }  
  
  public class DataGridBehavior : Behavior<DataGrid>  
  {  
    protected override void OnAttached()  
    {  
      AssociatedObject.PreviewKeyDown += OnPreviewKeyDown;  
      AssociatedObject.PreviewKeyUp += OnPreviewKeyUp;  
    }  
  
    private void OnPreviewKeyDown(object sender, KeyEventArgs e)  
    {  
      if (e.Key == Key.F3) ((ViewModel)(AssociatedObject.DataContext)).Info = "Pressed F3";  
      else if (e.Key == Key.LeftCtrl) LeftCtrl = true;  
      else if (e.Key == Key.F) ((ViewModel)(AssociatedObject.DataContext)).Info = "Pressed ctrl left + F";  
    }  
  
    private void OnPreviewKeyUp(object sender, KeyEventArgs e) { if (e.Key == Key.LeftCtrl) LeftCtrl = false; }  
  
    private bool LeftCtrl = false;  
  
  }  
}