Sergiy Baydachnyy

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Azure Mobile Services: Creating of Universal Application (part 2)

with 2 comments

Interface of our application (continued)

It’s time to implement business logic of our application. Since data classes are not related to specific interface, I am going to use the shared project to create all needed classes. Let’s create Code folder there and DataClasses.cs code file inside. We will create two classes there.

One of these classes should describe our data table in Azure Mobile Service. We need to use table and column names there in order to avoid using attributes or any other mapping approaches. So, our class may look like this:

public class NotificationData
{
public string id { get; set; }
public string text { get; set; }
public DateTime __createdAt { get; set; }
}

The second class is a utility class. I am going to use it as a class for loading out data from Azure Mobile. So, we can use the following code there:

public class DataClass
{
public static async Task<ICollection<NotificationData>> LoadData()
{
MobileServiceClient client =
           new MobileServiceClient("https://test-ms-sbaidachni.azure-mobile.net/");
var table=client.GetTable<NotificationData>();
var query = (from item in table
orderby item.__createdAt descending
select item).Take(100);
var items = await query.ToCollectionAsync();

return items;
}
}

Because we allowed to get data from Azure Mobile for Everyone, we don’t use any keys there. But I am downloading just 100 records from our database. Later you may add one more method which will implement incremental downloading. You can use Skip(n) method there in order to skip already downloaded records: .Skip(n).Take(100).

In order to finish our work with the Shared project, I will create Assets folder there and put logo for my applications there.

Since we already implemented all business logic and our applications allow us to receive notifications, we may finish work with interface of our applications.

In case of Windows 8 application I decided to use GridView control. We need to disable all “selection” and “click” functionality and show messages and dates there. Let’s review my code:

<Page.BottomAppBar>
<CommandBar>
<AppBarButton Label="Обновить" Icon="Refresh" Click="AppBarButton_Click"></AppBarButton>
</CommandBar>
</Page.BottomAppBar>

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<Image Source="Assets/football.png" Height="36" HorizontalAlignment="Left" Margin="120,30,0,10"></Image>
<GridView Name="myGrid" Grid.Row="1" Padding="120,40,100,80" SelectionMode="None" Visibility="Collapsed">
<GridView.ItemTemplate>
<DataTemplate>
<Grid Width="450" HorizontalAlignment="Left" Height="100" Background="Gray" >
<Grid.RowDefinitions>
<RowDefinition Height="Auto"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<TextBlock Text="{Binding __createdAt}" Style="{StaticResource CaptionTextBlockStyle}" Foreground="Green" Margin="5"></TextBlock>
<TextBlock Text="{Binding text}" Grid.Row="1" Style="{StaticResource BodyTextBlockStyle}" TextWrapping="Wrap" Margin="5"></TextBlock>
</Grid>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
<ProgressRing Name="progressBox" IsActive="True" HorizontalAlignment="Center" VerticalAlignment="Center" Width="100" Height="100" Grid.Row="1" Visibility="Visible"></ProgressRing>
<TextBlock Name="errorBox" TextWrapping="Wrap" Text="Что-то случилось с сетью. Попробуйте загрузить данные снова." Visibility="Collapsed"
HorizontalAlignment="Center" VerticalAlignment="Center" TextAlignment="Center"
Grid.Row="1" Style="{StaticResource HeaderTextBlockStyle}"></TextBlock>

<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="Common">
<VisualState x:Name="Loading">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="errorBox" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Collapsed" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="progressBox" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Visible" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="myGrid" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Collapsed" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Loaded">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="errorBox" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Collapsed" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="progressBox" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Collapsed" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="myGrid" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Visible" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Error">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="errorBox" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Visible" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="progressBox" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Collapsed" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="myGrid" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame Value="Collapsed" KeyTime="0"></DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>

</VisualStateManager.VisualStateGroups>
</Grid>

I know that it’s bigger than you imagined but it allows to show different parts of our interface based on different events in our application. We can divide this code in three parts.

In the first part we declared application bar control with refresh button there. I am going to use this button to allow user update interface in case user had opened application some time ago and it is still in the memory.

In the second part I declared Grid layout and some controls inside like GridView, Image and several textboxes with different messages. We are going to show GridView or massages based on situation.

In the last part I declared VisualStateManager control which allows to declare several custom states there. We will have three states:

· Loading – data is loading from Azure Mobile services;

· Loaded – data is loaded and ready to show;

· Error – we have problem with internet connection;

Depending on state, we are going to hide and show some parts of our interface.

Finally we need to implement some code, which will set state of our interface and this code will use our utility class in order to download data. I propose to use the following code inside MainPage.xaml.cs:

protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
LoadData();
}


private void AppBarButton_Click(object sender, RoutedEventArgs e)
{
LoadData();
}


private async void LoadData()
{
try
{
VisualStateManager.GoToState(this, "Loading", false);
var items = await DataClass.LoadData();
myGrid.ItemsSource = items;
VisualStateManager.GoToState(this, "Loaded", false);
}
catch(Exception ex)
{
VisualStateManager.GoToState(this, "Error", false);
}
}

The most important method there is LoadData. We are using of this method in order to move interface to the right state and it allows us to download and bind data as well.

In case of Windows Phone we will have the same code and XAML but I will change GridView control to ListView and I need to change some margins there. So, I will show just a piece of code with some differences there:

<ListView Name="myGrid"  Grid.Row="1" Padding="10" SelectionMode="None" >
<ListView.ItemTemplate>
<DataTemplate>
<Grid Margin="0,0,0,10">
<Grid.RowDefinitions>
<RowDefinition></RowDefinition>
<RowDefinition></RowDefinition>
</Grid.RowDefinitions>
<TextBlock Text="{Binding __createdAt}" Style="{StaticResource ListViewItemContentTextBlockStyle }" Foreground="Green"></TextBlock>
<TextBlock Text="{Binding text}" Grid.Row="1" Style="{StaticResource ListViewItemTextBlockStyle}" TextWrapping="Wrap" Margin="0,5,0,0"></TextBlock>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>

Therefore, we developed applications for Windows Phone and Windows 8, which allow us to get notifications about football games using Windows Notification Service and these applications can show the latest messages as well.

image

Publishing the applications

In order to publish your applications, you need to change the icons there. It’s the hardest part for developers, so, if you are going to publish the real application, you need ask designers about icons. Right after you changed all default icons, you may create Store packages for Windows Phone and Windows 8 separately. You can make it using context menu by calling Store->Create App Package item. Of course, you need to have access to your Store account and you need to reserve applications names there but we made it in the previous post.

Some time ago, Microsoft required Privacy policy for all Windows 8 applications, which used Internet connection. In case of Windows Phone you needed to create a settings page, which allows user to switch off notifications in your application. Today, you don’t have to do it. Privacy policy is still required but just for applications, which collect and store personal data (we don’t collect anything about users). Notification settings for Windows Phone 8.1 applications will be generated automatically and user can change it in any time using Settings->notifications+actions menu item (it’s strange but your application will appear there just after the first notification only).

Therefore, you may upload your packages, fill description and other fields and submit your applications for review. Usually review takes about 2-3 days but in my case it took about 2 hours.

My applications are available here:

http://www.windowsphone.com/s?appid=ff9b0b08-0a11-4eba-9362-9a023650dcfd

http://apps.microsoft.com/windows/app/fooball-ua-messages/870b8ea4-1385-4193-ab27-9836dd216711

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Written by Sergiy Baydachnyy

01/05/2015 at 7:58 PM

Posted in Microsoft Azure, Windows 8, Windows Phone

Tagged with

2 Responses

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  1. […] Azure Mobile Services: Creating of Universal Application (part 2) […]

  2. Hello admin do you need unlimited content for your
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    Lauren

    01/18/2015 at 10:58 AM


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