Bind event to ViewModel
InvokeCommandAction requires the ICommand
to be bound not an event handler as you've bound (EmployeeGrid_MouseLeftButtonUp).
So you can introduce a command in ViewModel and bind to it:
View Model:
public ICommand SomeActionCommand { get; set; }
XAML:
<i:InvokeCommandAction Command="{Binding SomeActionCommand}" />

Jelle Capenberghs
Graduated in June 2011 as Bachelor in Applied Computer Sciences. Now a junior .Net developer
Updated on June 04, 2022Comments
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Jelle Capenberghs about 1 year
I am using WPF and PRISM framework for my application. The pattern I am using is MVVM (Model - View - ViewModel) and I am trying to bring the MouseLeftButtonUp event from the code-behind in the View to the ViewModel (so the event will be according the MVVM rules). For now I have this:
View.xaml:
<DataGrid x:Name="employeeGrid" Height="250" Margin="25,0,10,0" ItemsSource="{Binding DetacheringenEmployeesModel}" IsReadOnly="True" ColumnHeaderStyle="{DynamicResource CustomColumnHeader}" AutoGenerateColumns="False" RowHeight="30"> <i:Interaction.Triggers> <i:EventTrigger EventName="MouseLeftButtonUp"> <i:InvokeCommandAction Command="{Binding EmployeeGrid_MouseLeftButtonUp}" /> </i:EventTrigger> </i:Interaction.Triggers> <DataGrid.Columns>
View.xaml.cs (code-behind):
public partial class UC1001_DashBoardConsultants_View { public UC1001_DashBoardConsultants_View(UC1001_DashboardConsultantViewModel viewModel) { InitializeComponent(); DataContext = viewModel; } }
ViewModel.cs:
public void EmployeeGrid_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) { // insert logic here }
The main idea is, when I click on a cell in the DataGrid, the event will fire. I first tried it in the code behind, and it worked. I got so far with the EventTriggers, but when I debug and click on a cell, my debugger doesn't come into the method.
Does anyone have an idea how to fix this? Thanks in advance!
PS: Does it also work with the (object sender) parameter when I do it like that? Because I need the DataGrid in my ViewModel to get the ActiveCell I just clicked on.
EDIT:
The event-binding worked with the Command!
I have this in my DataGrid:
<DataGridTextColumn Header="Okt" Width="*" x:Name="test" > <DataGridTextColumn.ElementStyle> <Style TargetType="{x:Type TextBlock}"> <Setter Property="Tag" Value="{Binding Months[9].AgreementID}"/>
How can I bind the Tag property to the ViewModel? I know it's already bound from the ViewModel, but as you can see the value comes from an Array/List and per column the value is different.
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Jelle Capenberghs over 11 yearsThanks, that worked perfectly! Do you also have a suggestion to pass the DataGrid along with the command (as a parameter or something) so I can access it in my ViewModel?
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sll over 11 years@Jelle Capenberghs : no, passing an entire UI container in ViewModel is not the MVVM approach, ViewModel should not know anything about specific UI implementation (today you're usign rid, but perhaps tomorrow - TreeView so ViewModel has to be refactored, this is wrong). What are you trying to do in this command?
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Jelle Capenberghs over 11 yearsI need to get the Cell I clicked in my ViewModel because the Cell contains a TextBlock with information I need in the ViewModel. - Already marked as answer because the ICommand was primarly what I needed!
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sll over 11 yearsI would suggest binding text itself
<TextBox Text="{Binding ViewModelProperty}" >
rather than such complext scenario with events -
Fandi Susanto over 9 yearsCould someone please tell me what namespace is "i"?
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sll over 9 yearsGoogle for "Interaction.Behavuiours"