SimpleFiltering: Programmatic access to series visibility

[David]

Hi,

I'm looking for ideas/guidance on how I can achieve the following:

I'd like to save which series are visible/hidden on form unload and restore which series are visible/hidden on form load. For this, I'm wondering how I can access the various Series<<seriesname>>Visibility properties in ExampleViewModel (for example, SeriesEU27Visibility, SeriesEuroAreaVisibility, SeriesJapanVisibility, SeriesUSVisibility) so that they can be read on form unload and then set in form load. In addition to setting these properties on form load, I would like to update the form accordingly to display/hide the correponding series and check/uncheck the corresponding check box in the legend.

I'm fairly new to .NET (I've been coding in VBA instead for over 10 years), so the .NET concepts are new, but programming concepts are familiar to me (I know OO programming concepts from Java, but are new to .NET concepts like ViewModels). I'd really appreciate any ideas or guidance on how I can achieve this.

Many thanks in advance!

Kind regards,
Dave.

[Missing User]

Hello David,

You can review the following demo, which gives an example on how to change the Series visibility according to a selected check box. In your case you can save the Series visibility immediately after a check box is clicked, e.g. in the ExampleViewModel.cs -- method ChangeSeriesVisibility(object parameter). You can implement custom logic for saving the visibility and retrieve and set the data in the constructor of the ExampleViewModel.cs. For example:

public ExampleViewModel()
{
    this.WireCommands();

    this.RetrieveSeriesVisibility();
}

private void FillSampleChartData()
{
    //this.SeriesEU27Visibility = retrieved data
}

You can also review the help topic about MVVM Support here.

I hope this helps.

Kind regards,

Polina

the Telerik team

[David]

Hi Polina,

Thanks for getting me started with saving the Series visibility. I'm able to successfully save and retreive the settings, however I have one remaining problem: after retreiving the saved state of the Series visibility, how do I update the checkbox in the legend to the corresponding value?

Here's how I've modified the SimpleFiltering demo (in VB) to save and retrieve the visibility settings:

1. I've added the following four settings to the Chart project properties:

• Name: SeriesEU27Visibility
  Type: Telerik.Windows.Controls.Charting.SeriesVisibility
  Scope: User
• Name: SeriesEuroVisibility
  Type: Telerik.Windows.Controls.Charting.SeriesVisibility
  Scope: User
• Name: SeriesJapanVisibility
  Type: Telerik.Windows.Controls.Charting.SeriesVisibility
  Scope: User

• Name: SeriesUSVisibility
  Type: Telerik.Windows.Controls.Charting.SeriesVisibility
  Scope: User

2. I have added the following procedure to ExampleViewModel.vb to retrieve the settings:

Private Sub RetrieveSeriesVisibility()
    Me.SeriesEU27Visibility = My.Settings.SeriesEU27Visibility
    Me.SeriesEuroAreaVisibility = My.Settings.SeriesEuroAreaVisibility
    Me.SeriesJapanVisibility = My.Settings.SeriesJapanVisibility
    Me.SeriesUSVisibility = My.Settings.SeriesUSVisibility
End Sub

3. I have modified the constructor to call this procedure:

Public Sub New()
    Me.WireCommands()
    Me.RetrieveSeriesVisibility()
End Sub

4. I have modified the ChangeSeriesVisibility() procedure to save the settings (I also did a little refactoring with a new ToggleSeriesVisibility() function):

Public Sub ChangeSeriesVisibility(ByVal parameter As Object)
    Dim seriesVisibility As SeriesVisibility
    Select Case parameter.ToString()
        Case "EU-27"
            seriesVisibility = ToggleSeriesVisibility(Me.SeriesEU27Visibility)
            Me.SeriesEU27Visibility = seriesVisibility
            My.Settings.SeriesEU27Visibility = seriesVisibility
            Exit Select
        Case "Euro area"
            seriesVisibility = ToggleSeriesVisibility(Me.SeriesEuroAreaVisibility)
            Me.SeriesEuroAreaVisibility = seriesVisibility
            My.Settings.SeriesEuroAreaVisibility = seriesVisibility
            Exit Select
        Case "Japan"
            seriesVisibility = ToggleSeriesVisibility(Me.SeriesJapanVisibility)
            Me.SeriesJapanVisibility = seriesVisibility
            My.Settings.SeriesJapanVisibility = seriesVisibility
            Exit Select
        Case "United States"
            seriesVisibility = ToggleSeriesVisibility(Me.SeriesUSVisibility)
            Me.SeriesUSVisibility = seriesVisibility
            My.Settings.SeriesUSVisibility = seriesVisibility
            Exit Select
        Case Else
            Exit Select
    End Select
    My.Settings.Save()
End Sub
Private Function ToggleSeriesVisibility(ByVal parameter As SeriesVisibility) As SeriesVisibility
    Dim seriesVisibility As SeriesVisibility
    If parameter = seriesVisibility.Collapsed OrElse parameter = seriesVisibility.Hidden Then
        seriesVisibility = seriesVisibility.Visible
    Else
        seriesVisibility = seriesVisibility.Hidden
    End If
    Return seriesVisibility
End Function

These changes successfully save and retrieve the settings. Any suggestions on how to get started to update the check box?

Kind regards,
Dave.

[Missing User]

Hello David,

You can set the checkbox values in code behind according to the retrieved data. For example you can get all generated checkboxes and their properties by ChildrenOfType<T> method which is part of the UIElementExtensions Class. In order to use it, you need to include namespace reference to Telerik.Windows.Controls. More information about it can be found here. After you have all generated checkboxes you can make a verification according to their content values and to differentiate them.

Best wishes,

Polina

the Telerik team

[David]

Hi Polina,

Thanks for your help! Here's the code I've added to update the checkboxes:

1. I added the following procedure to ExampleViewModel.vb to retrieve the visibility for a specific series based on its content:

Public Function RetrieveSeriesVisibility(ByVal parameter As Object) As SeriesVisibility
    Dim seriesVisibility As SeriesVisibility
    Select Case parameter.ToString()
        Case "EU-27"
            seriesVisibility = Me.SeriesEU27Visibility
            Exit Select
        Case "Euro area"
            seriesVisibility = Me.SeriesEuroAreaVisibility
            Exit Select
        Case "Japan"
            seriesVisibility = Me.SeriesJapanVisibility
            Exit Select
        Case "United States"
            seriesVisibility = Me.SeriesUSVisibility
            Exit Select
        Case Else
            Exit Select
    End Select
    Return seriesVisibility
End Function

2. I've modified Example.xaml to call a loaded event for the user control, ie:

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
    x:Class="Telerik.Windows.Examples.Chart.SimpleFiltering.Example"
    xmlns:example="clr-namespace:Telerik.Windows.Examples.Chart.SimpleFiltering"
    Loaded="UserControl_Loaded">

3. I added the "UserControl_Loaded" event to Example.xaml.vb:

Private Sub UserControl_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs)
    Dim viewModel As New ExampleViewModel
    For Each checkBox As CheckBox In Me.PrimaryLegend.ChildrenOfType(Of CheckBox)()
        checkBox.IsChecked = viewModel.RetrieveSeriesVisibility(checkBox.Content) = SeriesVisibility.Visible
    Next
End Sub

I hope this helps anyone else who wants to save and retrieve settings for series visibility. Thank you again to Polina for getting me started and helping me achieve this.

Kind regards,
Dave.