[ConditionalAttributes and binding its Active property to a VM]

The problem is solved using DataContext spy approach as described at http://www.codeproject.com/Articles/27432/Artificial-Inheritance-Contexts-in-WPF

[MVVM Samples]

That's briefly how we are doing it. In your view:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

xmlns:vm="clr-namespace:your-viewmodel-project-here">

<DataTemplate DataType="{x:Type vm:ChartWidgetViewModel}">

  <ContentControl Name="ChartWidgetViewModelContent" Template="{DynamicResource ViewModelLoadingTemplate}" />

</DataTemplate>

 

<ControlTemplate TargetType="{x:Type ContentControl}" x:Key="ChartWidgetViewContentTemplate">

<Grid>

<cfx:Chart>

 </cfx:Chart>

</Grid>

Then you can declare your VM class:

public class ChartWidgetViewModel

[ConditionalAttributes and binding its Active property to a VM]

Sorry, formatting got screwed up. Here it is again 

Dear Forum,

I am trying to solve a task of showing negative values in red only when the chart is of type Bar or Gantt. There is no code-behind and same View and View model are used for all charts.

Currently I am trying to make use of conditional attribute and its property Active to switch the colouring on/off when needed. I have a property in my view model like this:

 

 

public bool ShowNegativesInRed {

get { return (this.ChartConfig.WidgetType == ChartWidgetTypes.Gantt); }

}

Then in the View I am doing the following:

<cfx:Chart Gallery="{Binding Path=WidgetType, Mode=OneWay}" ...>

<cfx:Chart.ConditionalAttributes>

<cfx:ConditionalAttributes Fill="Red" Stroke="Red">

<cfx:ConditionalAttributes.Condition>

<cfx:RangeCondition To="0" Active="{Binding Path=ShowNegativesInRed}" />

</cfx:ConditionalAttributes.Condition>

</cfx:ConditionalAttributes>

</cfx:Chart.ConditionalAttributes>

...

</cfx:Chart>  

When I start the app and try to display the chart, "Active" is always resolved to true and I get a binding error:System.Windows.Data Error: 2 : Cannot find governing FrameworkElement or FrameworkContentElement for target element. BindingExpression:Path=ShowNegativesInRed; DataItem=null; target element is 'RangeCondition' (HashCode=20263529); target property is 'Active' (type 'Boolean')

Googling for this error I found someone advising to declare that thing causing the error in a local resource and use it from there, however I cannot think of how to move my cfx:RangeCondition to a local resource.

If anyone has an idea how to do that or maybe an alternative solution for my initial task that would be highly appreciated.

[ConditionalAttributes and binding its Active property to a VM]

Dear Forum,

I am trying to solve a task of showing negative values in red only when the chart is of type Bar or Gantt. There is no code-behind and same View and View model are used for all charts.

Currently I am trying to make use of conditional attribute and its property Active to switch the colouring on/off when needed. I have a property in my view model like this:

public bool ShowNegativesInRed

{

get { return (this.ChartConfig.WidgetType == ChartWidgetTypes.Gantt); }

}

Then in the View I am doing the following:

...

When I start the app and try to display the chart, "Active" is always resolved to true and I get a binding error:

System.Windows.Data Error: 2 : Cannot find governing FrameworkElement or FrameworkContentElement for target element. BindingExpression:Path=ShowNegativesInRed; DataItem=null; target element is 'RangeCondition' (HashCode=20263529); target property is 'Active' (type 'Boolean')

Googling for this error I found someone advising to declare that thing causing the error in a local resource and use it from there, however I cannot think of how to move my cfx:RangeCondition to a local resource.

If anyone has an idea how to do that or maybe an alternative solution for my initial task that would be highly appreciated.