CODEWITHSUNDEEP
c#uwp
Rpgccv
Rpgccv

Reputation: 137

UWP - How can i get a file (xml) from http?

I have this code to load the xml (to a List) and it works fine:

public MainPage()
{
    this.InitializeComponent();
    string XMLFilePath = Path.Combine(Package.Current.InstalledLocation.Path, "something.xml");
    XDocument loadedData = XDocument.Load(XMLFilePath);
}

what if I want to call the xml from my server!?

This is the last try: 

using System.Net.Http;
using System.Runtime.Serialization.Json;

...

private string jsonString;

    public MainPage()
    {
        this.InitializeComponent();

        loadData();

        //string XMLFilePath = Path.Combine(Package.Current.InstalledLocation.Path, "something.xml");
        XDocument loadedData = XDocument.Load(jsonString);

...

private async void loadData()
    {
        var httpClient = new HttpClient();
        HttpResponseMessage response = await httpClient.GetAsync(new Uri("http://domain.com/something.xml"));
        jsonString = await response.Content.ReadAsStringAsync();
    }

this is the error:

An exception of type 'System.ArgumentNullException' occurred in System.Xml.ReaderWriter.dll but was not handled in user code

Any help would be great.

Thanks.

Upvotes: 2

Views: 1970

Answers (3)

Grace Feng
Grace Feng

Reputation: 16652

You can simply use XmlDocument.LoadFromUriAsync | loadFromUriAsync methods to asynchronously loads an XML document from the specified location. This location can also be a Http link.

Just for a very simple test here:

<TextBlock x:Name="txt" />

code behind:

protected override async void OnNavigatedTo(NavigationEventArgs e)
{
    XmlDocument xmlDoc = await XmlDocument.LoadFromUriAsync(new Uri("http://domain.com/something.xml"));
    txt.Text = xmlDoc.GetXml().ToString();
}

Just be noticed that the namespace for xml document here is Windows.Data.Xml.Dom, not System.Xml. And I noticed that your Uri address is like http://domain.com/something.xml, maybe you are using the native server, when doing this, you may probably need to enable the Private Networks(Client & Server) capability in your project's manifest file.

Update:

Sorry I didn't know you want to use LinQ, to use XDocument to load xml, there are basically two methods: from string Uri or from stream, but for the first method, the Uri parameter must be a file system relative or absolute path.

So, here one method is you can save the xml to local file and load it again with XDocument, or you can use stream to achieve this, for example:

HttpClient client = new HttpClient();
var response = await client.GetStreamAsync("http://domain.com/something.xml");
XDocument xmlDoc = XDocument.Load(response);
txt.Text = xmlDoc.Document.ToString();

Upvotes: 5

lindexi
lindexi

Reputation: 4327

Your private async void loadData() is not await and the jsonString is null. You can 

private async void loadData()
{
    var httpClient = new HttpClient();
    HttpResponseMessage response = await httpClient.GetAsync(new Uri("http://domain.com/something.xml"));
    jsonString = await response.Content.ReadAsStringAsync();
    XDocument loadedData = XDocument.Load(jsonString);
}

 public MainPage()
 {
    this.InitializeComponent();

    loadData();
 }

Upvotes: 0

Dark Templar
Dark Templar

Reputation: 1155

You need to specify the address, try something like this:

public MainPage()
{
this.InitializeComponent();
string XMLFilePath = @"http://www.msn.com";
XmlDocument LoadedData = new XmlDocument();
LoadedData.Load(XMLFilePath);
}

If you want to use the XDocument object try to use the method "Parse" instead of "Load".

Upvotes: 1

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