Create Scheduled Toast Notification in Windows Phone Silverlight 8.1

Windows Phone 8.1 has a new feature called Toast Notification where we can show notifications to user and also show it in action center. We can also schedule the toast notification to appear at specific time. We can have scheduled toast notification in both Windows 8.1 Runtime app and Windows 8.1 Silverlight app.

Unlike Windows 8, Windows Phone only has one template for toast notification i.e. “toastText02”. It has application icon on left and accepts two text string with first with bold text and another with normal text. It is advisable to have very short strings to avoid truncation. We can use XML functions to set above two text.

 Dim toastTemplate As ToastTemplateType = ToastTemplateType.ToastImageAndText02

 Dim toastXml As XmlDocument = ToastNotificationManager.GetTemplateContent(toastTemplate)

 Dim toastTextElements As XmlNodeList = toastXml.GetElementsByTagName("text")

 toastTextElements(0).AppendChild(toastXml.CreateTextNode("File Downloaded"))

 toastTextElements(1).AppendChild(toastXml.CreateTextNode("Content.txt file downloaded from server"))

When user clicks on toast notification, the app gets launched. We can set launch attribute of toast element containing parameters which we can use to decide navigation page when the app is launched. We can write following code to set launch parameter.

Dim toastNode = toastXml.SelectSingleNode("/toast")

CType(toastNode, XmlElement).SetAttribute("launch", "?FileID=1")

So if our launch page is MainPage.xaml then uri would be “MainPage.xaml?FileID=1”. We can read the QueryString value in MainPage.xaml and do operation as per project requirement.

Protected Overrides Sub OnNavigatedTo(e As NavigationEventArgs)

        MyBase.OnNavigatedTo(e)

        If NavigationContext.QueryString.ContainsKey("FileID") = True Then

            Dim fileID As String = NavigationContext.QueryString("FileID")

            'Perform operation using fileID

       End If

 End Sub

Now we can create a ScheduledToastNotification where we can pass XmlDocument object containing information about toast and scheduled time when the toast notification should be displayed. We can optional also set “ID” property for ScheduledToastNotification so that we can cancel it in future if required.

Dim notification As New ScheduledToastNotification(toastXml, dueTime)

notification.Id = notificationID

We can also set MaximumSnoozeCount parameter to set maximum number of times notification should be displayed and SnoozeInterval parameter to set time interval between notifications. SnoozeInterval should be between 1 to 60 minutes and MaximumSnoozeCount should be between 1 to 5.

Dim notification As New ScheduledToastNotification(toastXml, dueTime, TimeSpan.FromMinutes(5), 3)

If we don’t want to show ToastNotification popup and only show the details in action center then we can set SuppressPopup property.

notification.SuppressPopup = True

It is advisable to check if any toast notification with similar ID is already created or not. If already created then you can notify the user or delete it.

Dim task = ToastNotificationManager.CreateToastNotifier.GetScheduledToastNotifications().Where(Function(f) f.Id = notificationID)

If task.Count > 0 Then

    ToastNotificationManager.CreateToastNotifier.RemoveFromSchedule(task.First)

End If

Now we can create ToastNotifier object and add scheduled notification using following code

ToastNotificationManager.CreateToastNotifier().AddToSchedule(notification)

For ToastNotification to work correctly we have to set Notification Service as “WNS” in WMAppManifest.xml file. This is one of the most important steps as your app could be reject in Certification process if “WNS” is not selected in Notification Service.

Below is complete code to create ScheduledToastNotification in Windows Phone Silverlight 8.1 app.

Private Sub CreateScheduleNotification(ByVal dueTime As Date, ByVal notificationID As Integer)

        Dim toastTemplate As ToastTemplateType = ToastTemplateType.ToastImageAndText02

        Dim toastXml As XmlDocument = ToastNotificationManager.GetTemplateContent(toastTemplate)

        Dim toastTextElements As XmlNodeList = toastXml.GetElementsByTagName("text")

        toastTextElements(0).AppendChild(toastXml.CreateTextNode("File Downloaded"))

        toastTextElements(1).AppendChild(toastXml.CreateTextNode("Content.txt file downloaded from server"))

        Dim toastNode = toastXml.SelectSingleNode("/toast")

        CType(toastNode, XmlElement).SetAttribute("launch", "?FileID=1")

        'Dim notification As New ScheduledToastNotification(toastXml, dueTime)

        Dim notification As New ScheduledToastNotification(toastXml, dueTime, TimeSpan.FromMinutes(5), 3)

        notification.Id = notificationID

        'notification.SuppressPopup =True 'To show notification only in action center

        Dim task = ToastNotificationManager.CreateToastNotifier.GetScheduledToastNotifications().Where(Function(f) f.Id = notificationID)

        If task.Count > 0 Then

            ToastNotificationManager.CreateToastNotifier.RemoveFromSchedule(task.First)

        End If

        ToastNotificationManager.CreateToastNotifier().AddToSchedule(notification)

    End Sub

Searching in Windows Phone ListBox

One of the most common way of searching in ListBox is to type text in TextBox and filter the ListBox items. In this article we will see how we can do this in Windows Phone application.

As you can see in above image, we have a TextBox where user can type, and a ListBox which get filtered based on text entered.

XAML Code

<phone:PhoneApplicationPage

    x:Class="PhoneApp1.MainPage"

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

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

    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"

    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"

    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"

    FontFamily="{StaticResource PhoneFontFamilyNormal}"

    FontSize="{StaticResource PhoneFontSizeNormal}"

    Foreground="{StaticResource PhoneForegroundBrush}"

    SupportedOrientations="Portrait" Orientation="Portrait"

    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->

    <Grid x:Name="LayoutRoot" Background="Transparent">

        <Grid.RowDefinitions>

            <RowDefinition Height="Auto"/>

            <RowDefinition Height="*"/>

        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->

        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12">

            <TextBlock x:Name="ApplicationTitle" TextAlignment="Center"  Text="SEARCHABLE LISTBOX" Style="{StaticResource PhoneTextNormalStyle}"/>

        </StackPanel>

        <!--ContentPanel - place additional content here-->

        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">

            <Grid.RowDefinitions>

                <RowDefinition Height="Auto"/>

                <RowDefinition Height="*"/>

            </Grid.RowDefinitions>

             

            <TextBox Grid.Row="0" Name="txtSearchText"/>

            <ListBox Grid.Row="1" Background="LightGray" Name="lstData" Margin="12,0"/>

        </Grid>

    </Grid>

  

</phone:PhoneApplicationPage>

Windows Phone has a class called CollectionView which allows grouping, sorting, filtering and navigation in a data collection. To create a collection view for a collection that implements IEnumerable, we can create a CollectionViewSource object, and add collection to the Source property. To filter the data based on TextBox text, we have to add event handler for Filter event.

Private Sub BindListBox()

       mTechnologiesCollectionSource.Source = mTechnologies

       Dim b As New Binding

       AddHandler mTechnologiesCollectionSource.Filter, AddressOf mTechnologiesCollectionSource_Filter

       b.Source = mTechnologiesCollectionSource

       lstData.SetBinding(ListBox.ItemsSourceProperty, b)

End Sub

  

  

Private Sub mTechnologiesCollectionSource_Filter(sender As Object, e As FilterEventArgs)

       Dim str As String = e.Item

       If String.IsNullOrWhiteSpace(txtSearchText.Text) = True OrElse str.ToUpperInvariant.StartsWith(txtSearchText.Text.ToUpperInvariant) = True Then

           e.Accepted = True

       Else

           e.Accepted = False

       End If

  

End Sub

In the above code, we are using "StartsWith" function to filter the Collection, and show the items which starts with text typed in TextBox. We can also use "Contains" function instead of "StartsWith" to show all the items which contains text typed in TextBox.

Private Sub mTechnologiesCollectionSource_Filter(sender As Object, e As FilterEventArgs)

       Dim str As String = e.Item

       If String.IsNullOrWhiteSpace(txtSearchText.Text) = True OrElse str.ToUpperInvariant.Contains(txtSearchText.Text.ToUpperInvariant) = True Then

           e.Accepted = True

       Else

           e.Accepted = False

       End If

  

End Sub

On TextChanged event on TextBox to reapply the filter we have to refresh the view using "CollectionViewSource.View.Refresh" function.

Imports System.Collections.ObjectModel

Imports System.Windows.Data

Partial Public Class MainPage

    Inherits PhoneApplicationPage

    Dim mTechnologies As New ObservableCollection(Of String)

    Dim mTechnologiesCollectionSource As New CollectionViewSource

    ' Constructor

    Public Sub New()

        InitializeComponent()

        FillListBox()

    End Sub

    Private Sub FillListBox()

        mTechnologies.Add("HTML")

        mTechnologies.Add("Silverlight")

        mTechnologies.Add("Visual Basic")

        mTechnologies.Add("Visual C#")

        mTechnologies.Add("Visual F#")

        mTechnologies.Add("Window Communication Foundation")

        mTechnologies.Add("Window Presentation Foundation")

        mTechnologies.Add("Window Phone")

        mTechnologies.Add("XML")

        mTechnologies.Add("XAML")

    End Sub

    Private Sub MainPage_Loaded(sender As Object, e As RoutedEventArgs) Handles Me.Loaded

        BindListBox()

    End Sub

    Private Sub BindListBox()

        mTechnologiesCollectionSource.Source = mTechnologies

        Dim b As New Binding

        AddHandler mTechnologiesCollectionSource.Filter, AddressOf mTechnologiesCollectionSource_Filter

        b.Source = mTechnologiesCollectionSource

        lstData.SetBinding(ListBox.ItemsSourceProperty, b)

    End Sub

    Private Sub mTechnologiesCollectionSource_Filter(sender As Object, e As FilterEventArgs)

        Dim str As String = e.Item

        If String.IsNullOrWhiteSpace(txtSearchText.Text) = True OrElse str.ToUpperInvariant.StartsWith(txtSearchText.Text.ToUpperInvariant) = True Then

            e.Accepted = True

        Else

            e.Accepted = False

        End If

    End Sub

    Private Sub txtSearchText_TextChanged(sender As Object, e As TextChangedEventArgs) Handles txtSearchText.TextChanged

        mTechnologiesCollectionSource.View.Refresh()

    End Sub

End Class

You can also refer following links to know more about CollectionViewSource

http://msdn.microsoft.com/en-us/library/system.windows.data.collectionview.aspx
http://msdn.microsoft.com/en-us/library/ms752348.aspx