Hi,
i followed your post to write a custom cell presenter control:
<igDP:XamDataGrid Name="DataGrid" > <igDP:XamDataGrid.Resources> <Style x:Key="CellStyle" TargetType="{x:Type igDP:CellValuePresenter}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type igDP:CellValuePresenter}"> <StackPanel Orientation="Horizontal"> <!--<Label Content="{TemplateBinding DataContext}" Width="{TemplateBinding Width}" Height="{TemplateBinding Height}"></Label>--> <my:CWpfIgZelleGui DataContext="{TemplateBinding DataContext}" Width="{TemplateBinding Width}" Height="{TemplateBinding Height}" /> </StackPanel> </ControlTemplate> </Setter.Value> </Setter> </Style> </igDP:XamDataGrid.Resources> </igDP:XamDataGrid>
In the code i set the style and my cell control is displayed.
But the problem is with the datacontext:
The datacontext contains the DataRecord. How should i figure out, which cell to display?
Thank you very much! It works with both.
I'm setting aCell.VAlue = aString and aCell.Tag = aViewModel. The value is for sorting and grouping by DataGrid and the viewmodel is for my control to display the content. That's why i needed the cell to obtain the viewmodel in the tag property.
When i understand correctly i still need to implement the field property in my control, right.
So for my usecase it would have helped a bit to have a cell-property in the CellValuePresenter. With this i don't need to implement the field-property and the additional handling. Maybe you want to implement this in a future release.
Hello,
Probably there is a simpler solution, but I was not able to fully understand your question :
"How should i figure out, which cell to display?"
Yes, the DataContext is the DataRecord. If you are trying to figure our which field uses the specific CellValuePresenter, then you can bind to the Field property of the CVP ( use TemplateBinding Path=Field) or use a RelativeSource - TemplatedParent, Path=Field.
Ok, i made a workouround:
[1] I added a DependencyProperty 'Field' to CWpfIgCellGui-control
' [2] I created a celltemplate in the codebehind for each Cell
' [3] in the template i assigned the field to the property
[4] in CWpfIgCellGui i added another datacontext which i set to the cell which i can determine by evaluating [5] the datacontext for the control (which points to datarecord) and the field from my own dependency property.
that is quite sophisticated to realize a standard usecase (and i guess displaying a cell value in a cellvaluepresenter should be a standard use case) so i hope there is a better solution. (The solution for my understanding would be that the data context contains the cell, not the record)
here's the code:
' [1] I added a DependencyProperty 'Field' to CWpfIgCellGui-control
Public Shared ReadOnly FieldProperty As DependencyProperty = DependencyProperty.Register("Field", GetType(Field), GetType(CWpfIgZelleGui), New PropertyMetadata(AddressOf FieldChanged)) Public Property Field() As Field Get Return DirectCast(Me.GetValue(FieldProperty), Field) End Get Set(ByVal value As Field) Me.SetValue(FieldProperty, value) End Set End Property
Dim aField As New UnboundField Dim aCellStyle As New Style aCellStyle.TargetType = GetType(CellValuePresenter) Dim aTemplateSetter As New Setter aTemplateSetter.Property = CellValuePresenter.TemplateProperty Dim aTemplate As New ControlTemplate(GetType(CellValuePresenter)) Dim aTemplateElementFactory As New FrameworkElementFactory(GetType(CWpfIgZelleGui)) aTemplateElementFactory.SetValue(CWpfIgZelleGui.FieldProperty, aField) ' ' [3] in the template i assigned the field to the property aTemplate.VisualTree = aTemplateElementFactory aTemplate.Seal() aTemplateSetter.Value = aTemplate aCellStyle.Setters.Add(aTemplateSetter) aField.Settings.CellValuePresenterStyle = aCellStyle aField.Name = Me.UnboundFieldName aField.DataType = GetType(Integer)
' [4]
Private Sub CWpfIgZelleGui_DataContextChanged(ByVal sender As Object, ByVal e As System.Windows.DependencyPropertyChangedEventArgs) Handles Me.DataContextChanged Me.GridDataContextFüllen() End Sub Private Shared Sub FieldChanged(ByVal d As System.Windows.DependencyObject, ByVal e As System.Windows.DependencyPropertyChangedEventArgs) DirectCast(d, CWpfIgZelleGui).GridDataContextFüllen() End Sub
Private Sub GridDataContextFüllen() Dim aField As Field = Me.Field Dim aRecord As DataRecord = DirectCast(Me.DataContext, DataRecord) Dim aCell As Cell If aRecord IsNot Nothing And aField IsNot Nothing Then aCell = aRecord.Cells(aField) ' [5] evaluating the cell which we need to display the cell value. Else aCell = Nothing End If Me.GridM.DataContext = aCell End Sub