Read XML file In MAUI project

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• .NET MAUI on GitHub
• .NET MAUI Blog
• .NET MAUI Installation
• .NET MAUI Documentation
• Weather '21 Sample App

Hi Amroun,

If you're using the CollectionView, I'm afraid I can't be of much assistance because that is a Microsoft control. You can ask for help form Microsoft about why TapGesture Recognizer doesn't work in a CollectionView here => .NET MAUI - Microsoft Q&A.

Instead, you should use the control's selection feature, a CollectionView has a SelectionChanged event.

private void BooksListControl_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
    var selectedBook = e.CurrentSelection as Book;
    Debug.WriteLine($"You have selected {selectedBook.Title}");
}

Precise Example

For a real example, I can show this using a Telerik UI for MAUI RadListView and our powerful SelectionChanged event. See this article for explanation and code examples => .NET MAUI ListView Documentation - Selection. I have also re-written my demo from scratch fo r you to see this in action.

First, lets review the layout:

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:telerik="http://schemas.telerik.com/2022/xaml/maui"
             x:Class="SelectionExample.MainPage">
    <Grid RowSpacing="25"
          RowDefinitions="Auto, *"
          Padding="{OnPlatform iOS='30,60,30,30', Default='30'}">

        <Label x:Name="StatusLabel"
               Text="Loading..."
               FontSize="14"
               FontAttributes="Bold"
               HorizontalOptions="Center" />

        <telerik:RadListView x:Name="BooksListControl"
                             SelectionChanged="BooksListControl_OnSelectionChanged"
                             Grid.Row="1">
            <telerik:RadListView.ItemTemplate>
                <DataTemplate>
                    <telerik:ListViewTemplateCell>
                        <StackLayout Margin="0,0,0,10">
                            <Label Text="{Binding Title}" />
                            <Label Text="{Binding ISBN}" />
                            <Label Text="{Binding Price}" />
                        </StackLayout>
                    </telerik:ListViewTemplateCell>
                </DataTemplate>
            </telerik:RadListView.ItemTemplate>
        </telerik:RadListView>
    </Grid>
</ContentPage>

In the page's OnAppearing method, we load the data and in the SelectionChanged event we just show the selection

public partial class MainPage : ContentPage
{
    private readonly ObservableRangeCollection<Book> books = new();

	public MainPage()
	{
		InitializeComponent();
        
        BooksListControl.ItemsSource = books;
	}

    // When the page appears, check to see if we already have books loaded:
    // - If the books list is empty, then load data from XML file and add them to the list.
    // - If the books list is not empty, return.
    protected override async void OnAppearing()
    {
        base.OnAppearing();

        if (books.Any())
            return;

        StatusLabel.Text = "loading XML file...";

        await using var stream = await FileSystem.OpenAppPackageFileAsync("Books.xml");

        StatusLabel.Text = "Deserializing XML data...";

        var serializer = new System.Xml.Serialization.XmlSerializer(typeof(XmlData));

        var result = (XmlData)serializer.Deserialize(stream);
        
        var loadedData = result?.Books.ToList();

        switch (loadedData?.Count)
        {
            case 0:
                StatusLabel.Text = "No items were found in the data.";
                break;
            case > 0:
                StatusLabel.Text = $"{loadedData.Count} Books Loaded!";
                books.AddRange(loadedData);
                break;
            default:
                StatusLabel.Text = "Something went wrong";
                break;
        }

        StatusLabel.Text = "Data loaded! Awaiting selection...";
    }

    // When selection changes in the RadListView, read the first selected item's Title
    private void BooksListControl_OnSelectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (e.NewItems?.Count > 0 && e.NewItems[0] is Book selectedBook)
        {
            StatusLabel.Text = $"You have selected {selectedBook.Title}";
        }
    }
}

Here's a screenshot at runtime after selection:

Note: I know you want to navigate to a new page using that selection, for this you can research about .NET MAUI naviagtion here => .NET MAUI Shell navigation - .NET MAUI | Microsoft Learn.

General Advice

You never want to use a Gesture Recognizer in a list control that also has gesture recognition (selection, swipe, etc), this usually breaks any existing selection mechanism because it interferes with the internal mechanisms for selection. Either your recognizer will be broken, or the list control's will be broken.

I hope this helps clarify how you would handle selection. Please download and experiment with my demo to understand the setup further.

Thank you for your review, but I am missing the package for Telerik. I copied your NuGet.Config file in the root of my project but it does not recognize Telerik and useTelerik (); I tried to install the package but there are many, I don't know which one.

Thank you

I installed the 30-day free version for Telerik for Maui but nothing has changed. I still have the same problem.

Severity Code Description Project File Line Suppression State
Error CS0246 The type or namespace name 'Telerik' could not be found (are you missing a using directive or an assembly reference?) TestSelectxml (net7.0-android), TestSelectxml (net7.0-ios), TestSelectxml (net7.0-maccatalyst), TestSelectxml
Severity Code Description Project File Line Suppression State
Error XLS0414 The type 'RadListView' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built. TestSelectxml

Severity Code Description Project File Line Suppression State
Error CS1061 'MauiAppBuilder' does not contain a definition for 'UseTelerik' and no accessible extension method 'UseTelerik' accepting a first argument of type 'MauiAppBuilder' could be found (are you missing a using directive or an assembly reference?) TestSelectxml (net7.0-android), TestSelectxml (net7.0-ios), TestSelectxml (net7.0-maccatalyst), TestSelectxml (net7.0-windows10.0.19041.0)

Hallo,

I did the Terelik installation steps but the last step for the package I did not have the Telerik.UI.for.Maui I sectioned the Telerik server and I wrote my user name and password but I have no result.

and here is my NuGet.config file

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
    <add key="telerik.com" value="https://nuget.telerik.com/v3/index.json" />
  </packageSources>
  <packageRestore>
    <add key="enabled" value="True" />
    <add key="automatic" value="True" />
  </packageRestore>
  <bindingRedirects>
    <add key="skip" value="False" />
  </bindingRedirects>
  <packageManagement>
    <add key="format" value="0" />
    <add key="disabled" value="False" />
  </packageManagement>
  <packageSourceCredentials>
    <telerik.com>
        <add key="Username" value="my-email-address" />
        <add key="Password" value="code-generated-by-progress-control-panel" />
      </telerik.com>
  </packageSourceCredentials>
</configuration>

[EDITED by Telerik Admin] - Removed sensitive information from configuration file.

Hi Amroun, that's strange. Just to make sure, I checked your account and indeed, you do not have any Telerik licenses on your account. This is why the Telerik NuGet server isn't giving you anything.

Please start a new trial license for Telerik UI for MAUI, then wait about 5-10 minutes for our NuGet server to sync up. You will then see Telerik.UI.for.Maui.Trial" in the feed (make sure you update my demo project to use the ".Trial" package name).

Alternatively, if your company purchased the license(s), then ask them to assign you as the Licensed User. This only take 10 seconds by using the Manage License Users portal.

Further Assistance

Are you here for Telerik UI for MAUI help? Or just asking for general .NET MAUI assistance? This forum is for the Telerik controls, this is why I am giving advice in the context of the Telerik UI for MAUI's RadListView and demonstrating its selection features. If you do not want this, then just replace the Telerik RadListView with a simpler Microsoft CollectionView (like my initial project for Daniel uses).

• For assistance with general .NET topics, like CollectionView selection, File IO, etc, you can ask Microsoft for help here => .NET MAUI - Microsoft Q&A, you have two options:
• For help with the Telerik controls, you have two options:
  • Post here in the forums of you want the question to be public and get participation from the community.
  • Open a professional Technical Support case => https://www.telerik.com/account/support-center/contact-us  (you get technical support during your trial)

Hallo,

can you help me I'm still working in the same project that you sent me for the list of an XML document for the selection of data it works, now I'm trying to download the xml of the list from Another file in the Android mobile is an update that is done every day for this list.

thank  you .

HI Yasmina, this is also not related to Telerik, so Telerik Support or Telerik UI for MAUI is unable to provide much assistance with it.

I have 3 places where you can ask for help:

• .NET MAUI - Microsoft Q&A (best)
• https://stackoverflow.com
• https://www.reddit.com/r/dotnet/ 

If the XML file is from the internet, then you will want to ask for help with "HttpClient". If the file is somewhere else on the device, then you ask for help with "File system".

Quick Example

This is not an official Telerik-supported code snippet, it is a head start for you by showing you basic usage of HttpClient to download something from the internet, and then saves it to the local AppData folder. From here, you can use the Microsoft Documentation and ask for help in one of those 3 places I listed above.

private async Task<string> DownloadAndSaveMyXmlFile()
{
    var client = new HttpClient();
    byte[] xmlBytes = await client.GetByteArrayAsync("https://the-website-where-my-file-is.com/myfile.xml");
    string appdataDirectory = FileSystem.Current.AppDataDirectory;
    string filename = "myfile.xml";
    string filePath = Path.Combine(appdataDirectory, filename);
    await System.IO.File.WriteAllBytesAsync(filePath, xmlBytes);
    return filePath;
}

Hello Lance ,
Thank you for your help, for my project is that I have to load the document from another folder in the mobile, but I will understand the example you gave me but it is a download from the internet .and also I will contact the services (File system).

thank you very much for your answer.

Hi Amroun, 
Could you please share what example is required? If you want to load data in the DataGrid from XML files, we have examples in our ControlsSample application. - DataGrid examples. The xml files are inside the Common folder : OrdersDataSource.xml and PeopleDataSource.xml. You can review the code and the implementation. Please note that how to read the file is up to you.

If you have issues populating the DataGrid with data, please open a separate ticket for this case and send us exact steps you did and code you used. Also share which examples from the documentation you have used? If there is an issue, I will address it. 

Thank you.

Hallo Didi ,

thank you for your cooperation,

I will explain a part of my project to you: I scan pieces  of big machines with the barecode in the first page and each machine contains different components for example the engine, the driver's cabin, Dcv ext ...
the scanner data will be filled in the Data Grid; after when all the parts of the machine are scanned they will be saved in the DataGrid and generate an XML file

Hi,
I would like to ask you to open a support ticket and share more details on the setup you have. Also describe what is the exact issue with populating the DataGrid with data?

You populate the control with data and it is visualized in the cells. Then you can execute operations like filtering ,sorting ,grouping, editing the data in the control. If you want to generate xml file from the collection bound to the DataGrid ItemsSource, this is a custom logic implementation that must be done on your side.
Here are links that could be of help:   
https://stackoverflow.com/questions/8633398/xmlserialize-an-observablecollection 
and  https://stackoverflow.com/questions/39345073/how-to-convert-an-observablecollection-to-xml-file-from-c

Hi Yasmina,

It looks like you have not yet activated your Telerik account, this will prevent you from using certain features like professional technical support.

I have manually re-sent the activation email, please open that and confirm your account as soon as possible (check your spam folder if you don't see it). Once you've activated your account by confirming your email, you can move on with my instructions below.

My previous reply has instructions on how to open a Support Ticket, but I'll repeat the information here in a little more detail:

1. Go to your Support Center page => https://www.telerik.com/account/support-center/
2. Select "Contact Us"
3. Select "Technical Support"

Please keep in mind that we may refer you to other help resources if your inquiries are not related to the Telerik controls.

hallo Lance, I had the email to activate my Telerik account from the beginning but it always sends me this message:

Your Activation Link is Invalid

hallo Lance,

I apologize but I received no email to activate my account. I even looked in spam but there is nothing.

 Hi Yasmina,

Regarding xml file generation from collection of data, I have send a reply in one of my previous posts. I am pasting it here: 

If you want to generate xml file from the collection bound to the DataGrid ItemsSource, this is a custom logic implementation that must be done on your side.
Here are links that could be of help:   
https://stackoverflow.com/questions/8633398/xmlserialize-an-observablecollection
and  https://stackoverflow.com/questions/39345073/how-to-convert-an-observablecollection-to-xml-file-from-c 

This question is not a specific question for the RadDataGrid control. As I explained this requires custom logic implementation. 

Hallo Lance ,

I have not yet had my email to activate my account; I am still waiting for a sign from you.

THANKS