MVVM Support

The Telerik RadTimeBar control can be used with great success with the Model-View-ViewModel (MVVM) pattern. This help topic will demonstrate how to use the control with the pattern.

1. Create new ViewModel class that inherits the ViewModelBase abstract class:

   • C#
   • VB.NET

       public class ExampleViewModel : ViewModelBase 
           { 
               private DateTime periodStart; 
               private DateTime periodEnd; 
               private IEnumerable<double> data; 
               private DateTime visiblePeriodStart; 
               private DateTime visiblePeriodEnd; 
    
               [TypeConverter(typeof(DateTimeTypeConverter))] 
               public DateTime PeriodStart 
               { 
                   get 
                   { 
                       return this.periodStart; 
                   } 
                   set 
                   { 
                       if (this.periodStart == value) 
                           return; 
    
                       this.periodStart = value; 
                       this.OnPropertyChanged("PeriodStart"); 
                   } 
               } 
    
               [TypeConverter(typeof(DateTimeTypeConverter))] 
               public DateTime PeriodEnd 
               { 
                   get 
                   { 
                       return this.periodEnd; 
                   } 
                   set 
                   { 
                       if (this.periodEnd == value) 
                           return; 
    
                       this.periodEnd = value; 
                       this.OnPropertyChanged("PeriodEnd"); 
                   } 
               } 
    
               [TypeConverter(typeof(DateTimeTypeConverter))] 
               public DateTime VisiblePeriodStart 
               { 
                   get 
                   { 
                       return this.visiblePeriodStart; 
                   } 
                   set 
                   { 
                       if (this.visiblePeriodStart == value) 
                           return; 
    
                       this.visiblePeriodStart = value; 
                       this.OnPropertyChanged("VisiblePeriodStart"); 
                   } 
               } 
    
               [TypeConverter(typeof(DateTimeTypeConverter))] 
               public DateTime VisiblePeriodEnd 
               { 
                   get 
                   { 
                       return this.visiblePeriodEnd; 
                   } 
                   set 
                   { 
                       if (this.visiblePeriodEnd == value) 
                           return; 
    
                       this.visiblePeriodEnd = value; 
                       this.OnPropertyChanged("VisiblePeriodEnd"); 
                   } 
               } 
    
               public IEnumerable<double> Data 
               { 
                   get 
                   { 
                       if (data == null) 
                       { 
                           Random r = new Random(); 
                           List<double> collection = new List<double>(); 
                           for (DateTime date = PeriodStart; date <= PeriodEnd; date = date.AddDays(1)) 
                           { 
                               collection.Add(r.Next(0, 100)); 
                           } 
                           this.data = collection; 
                       } 
                       return this.data; 
                   } 
               } 
           } 

       Public Class ExampleViewModel Inherits ViewModelBase 
                   Private periodStart_Renamed As Date 
                   Private periodEnd_Renamed As Date 
                   Private data_Renamed As IEnumerable(Of Double) 
                   Private visiblePeriodStart_Renamed As Date 
                   Private visiblePeriodEnd_Renamed As Date 
    
                   <TypeConverter(GetType(DateTimeTypeConverter))> 
                   Public Property PeriodStart() As Date 
                         Get 
                               Return Me.periodStart_Renamed 
                         End Get 
                         Set(ByVal value As Date) 
                               If Me.periodStart_Renamed Is value Then 
                                     Return 
                               End If 
    
                               Me.periodStart_Renamed = value 
                               Me.OnPropertyChanged("PeriodStart") 
                         End Set 
                   End Property 
    
                   <TypeConverter(GetType(DateTimeTypeConverter))> 
                   Public Property PeriodEnd() As Date 
                                                       Get 
                               Return Me.periodEnd_Renamed 
                         End Get 
                         Set(ByVal value As Date) 
                               If Me.periodEnd_Renamed Is value Then 
                                     Return 
                               End If 
    
                               Me.periodEnd_Renamed = value 
                               Me.OnPropertyChanged("PeriodEnd") 
                         End Set 
                   End Property 
    
                   <TypeConverter(GetType(DateTimeTypeConverter))> 
                   Public Property VisiblePeriodStart() As Date 
                         Get 
                               Return Me.visiblePeriodStart_Renamed 
                         End Get 
                         Set(ByVal value As Date) 
                               If Me.visiblePeriodStart_Renamed Is value Then 
                                     Return 
                               End If 
    
                               Me.visiblePeriodStart_Renamed = value 
                               Me.OnPropertyChanged("VisiblePeriodStart") 
                         End Set 
                   End Property 
    
                   <TypeConverter(GetType(DateTimeTypeConverter))> 
                   Public Property VisiblePeriodEnd() As Date 
                         Get 
                               Return Me.visiblePeriodEnd_Renamed 
                         End Get 
                         Set(ByVal value As Date) 
                               If Me.visiblePeriodEnd_Renamed Is value Then 
                                     Return 
                               End If 
    
                               Me.visiblePeriodEnd_Renamed = value 
                               Me.OnPropertyChanged("VisiblePeriodEnd") 
                         End Set 
                   End Property 
    
                   Public ReadOnly Property Data() As IEnumerable(Of Double) 
                         Get 
                               If data_Renamed Is Nothing Then 
                                     Dim r As New Random() 
                                     Dim collection As New List(Of Double)() 
                                     Dim [date] As Date = PeriodStart 
                                     Do While [date] <= PeriodEnd 
                                           collection.Add(r.Next(0, 100)) 
                                           [date] = [date].AddDays(1) 
                                     Loop 
                                     Me.data_Renamed = collection 
                               End If 
                               Return Me.data_Renamed 
                         End Get 
                   End Property 
       End Class 

   The PeriodStart and PeriodEnd properties will specify the time period that the TimeBar will visualize. The VisiblePeriodStart and VisiblePeriodEnd properties will specify the visible time period on the screen. The Data collection will be used as datasource for the SparkLines that will be seen inside the TimeBar control.

2. Add new RadTimeBar and RadSparkLine declarations in XAML and bind the mentioned properties:

   The properties should be bound using TwoWay binding. This is required because of the coercing of the values that happens when a binding is executed.

   • XAML

       <UserControl.DataContext> 
               <local:ExampleViewModel PeriodStart="01/01/2012" PeriodEnd="01/01/2013" VisiblePeriodStart="01/01/2012" VisiblePeriodEnd="01/01/2013" /> 
           </UserControl.DataContext> 
    
           <Grid x:Name="LayoutRoot" Background="White"> 
               <telerik:RadTimeBar Margin="8,8,8,0" Height="150" VerticalAlignment="Top" 
                                   PeriodStart="{Binding PeriodStart, Mode=TwoWay}" 
                                   PeriodEnd="{Binding PeriodEnd, Mode=TwoWay}" 
                                   VisiblePeriodStart="{Binding VisiblePeriodStart, Mode=TwoWay}" 
                                   VisiblePeriodEnd="{Binding VisiblePeriodEnd, Mode=TwoWay}"> 
                   <telerik:RadTimeBar.Intervals> 
                       <telerik:YearInterval/> 
                       <telerik:QuarterInterval/> 
                       <telerik:MonthInterval/> 
                       <telerik:WeekInterval /> 
                       <telerik:DayInterval /> 
                   </telerik:RadTimeBar.Intervals> 
    
                   <telerik:RadLinearSparkline ItemsSource="{Binding Data}" /> 
               </telerik:RadTimeBar> 
           </Grid> 

The result can be seen below: