Binding viewmodel property to view property in code behind using Prism

Question

I use C# 7, Prims 6.3 and SyncFusion Grid Control for developing my application ( https://help.syncfusion.com/wpf/grid/getting-started ).
My problem is next: Grid Control is just "emulate" WPF-style, so I can add it into XAML: <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto" Grid.Row="0" CanContentScroll="True"> <syncfusion:GridControl x:Name="WorksheetGrid"/> </ScrollViewer>

But I can't bind it with my viewmodel properties which contain all data for table.
So I used EventAggregator for sending new data to view from viewmodel:

`

private void OnSelectWorksheetEvent(WorksheetSelectedEventArgs args) {
  _regionManager.RequestNavigate(RegionNames.RootRegion, "WorksheetView");
  _eventAggregator.GetEvent<WorksheetDataRecievedEvent>().
      Publish(new WorksheetDataEventArgs(_model.ReadRowHeader(args.WshCode),
      _model.ReadColHeader(args.WshCode), _model.ReadCells(args.WshCode)));
}

`

But this is ugly arhictecture, because I duplicate all data structure in view code behind:

`

void OnWorksheetDataRecievedEvent(WorksheetDataEventArgs args) {
            WorksheetGrid.QueryCellInfo -= new GridQueryCellInfoEventHandler(gridControl_QueryCellInfo);

            ClearWorksheetData();
            ClearWorksheetModel();

            RowHeaderHelper.RowHeader = args.RowHeader;
            ColHeaderHelper.ColHeader = args.ColHeader;
            CellHelper.Cells = args.Cells;

            WorksheetGrid.Model.RowCount = RowHeaderHelper.HeaderSize() + 1;
            WorksheetGrid.Model.ColumnCount = ColHeaderHelper.HeaderSize() + 1;

            WorksheetGrid.QueryCellInfo += new GridQueryCellInfoEventHandler(gridControl_QueryCellInfo);
            WorksheetGrid.Model.ResizeRowsToFit(GridRangeInfo.Row(0), GridResizeToFitOptions.IncludeHeaders);
        }

`

I understand that direct access to viewmodel properties from view is anti-mvvm, but I'm limited with SyncFusion gui component

So my questions: 1. How can I access to viewmodel's properties from view code behind? 2. How can I trigger some function in view code behind when property in viewmodel is changed?

Thanks.

Answer 1

It's been a while since I used Prism (and yes, your current solution is very anti-mvvm and I would suggest you try and wrap the problematic controls), but I think that for:

1. In the view this.DataContext should be the view model.

2. I would register to the PropertyChanged event in the view model to get updates on it's values (view models usually implement the INotifyPropertyChanged interface).

Hope it helps!