I am consuming a web service so I added service reference to my application.
I need to display the data on listBox. for this I only wrote the following code but its not working and I keep getting an error. My code is
public Antocids()
{
InitializeComponent();
ObservableCollection<Class1> p = new ObservableCollection<Class1>();
ServiceReference3.ProductsClient client = new ServiceReference3.ProductsClient();
client.getProdDetailsCompleted += new EventHandler<ServiceReference3.getProdDetailsCompletedEventArgs>(client_getProdDetailsCompleted);
client.getProdDetailsAsync();
}
private void client_getProdDetailsCompleted(object sender, ServiceReference3.getProdDetailsCompletedEventArgs e)
{
ObservableCollection<Class1> p = e.Result; //here I'm getting the error
listBox1.DataContext=p;
}
please tell me the exact procedure
I guess that your service reference does not return a result of type ObservableCollection<Class1>. In that case it makes no sense to treat it as such. What you should instead do is add the elements to an ObservableCollection when you receive your result:
ObservableCollection<Class1> p = new ObservableCollection<Class1>();
public Antocids()
{
InitializeComponent();
listBox1.DataContext=p;
ServiceReference3.ProductsClient client = new ServiceReference3.ProductsClient();
client.getProdDetailsCompleted += new EventHandler<ServiceReference3.getProdDetailsCompletedEventArgs>(client_getProdDetailsCompleted);
client.getProdDetailsAsync();
}
private void client_getProdDetailsCompleted(object sender, ServiceReference3.getProdDetailsCompletedEventArgs e)
{
p.Clear(); // assuming you want to clear the data each time you get a new result
foreach(var result in e.Result)
p.Add(result) // assuming that e.Result holds an IEnumerable of Class1.
}
If your service doesn't return some sort of collection of type Class1, then you will need to manually parse it into Class1 and then add it to the observable collection.
Related
I am writing a piece of code but cannot figure out why it is showing some (from my point of view) weird behaviour. I get this is due to how I have written the code, but I cannot understand why it is not doing what I want it to do.
I have an eventhandler:
private void heatFinishedHandler(object sender, List<Kart> e)
{
mainForm.enableControls();
server.karts = e;
}
If I add e.Clear(); to it, it also clears server.karts.
The argument e comes from another class:
private List<Kart> kartlist = new List<Kart>();
heatFinished?.Invoke(this, kartlist);
The heatFinished event and the heatFinishedEventHandler are connected.
What do I need to do to get e by value, instead of reference? Or is it a value type, but is it pointing to kartlist?
I want to be able to get the value of e and store it in server.karts, not being able to change kartlist.
Make a copy of the list you pass to the function like
private List<Kart> kartlist = new List<Kart>();
heatFinished?.Invoke(this, kartlist.ToList());
Or do it inside the function like
private void heatFinishedHandler(object sender, List<Kart> e)
{
mainForm.enableControls();
server.karts = e.ToList();
}
.ToList() will make a new List-instance with the same values as the original one.
Wierd behaviour when passing values to and from second form.
ParameterForm pf = new ParameterForm(testString);
works
ParameterForm pf = new ParameterForm();
pf.testString="test";
doesn't (testString defined as public string)
maybe i'm missing something? Anyway I'd like to make 2nd variant work properly, as for now - it returns null object reference error.
Thanks for help.
Posting more code here:
calling
Button ParametersButton = new Button();
ParametersButton.Click += delegate
{
ParameterForm pf = new ParameterForm(doc.GetElementById(ParametersButton.Tag.ToString()));
pf.ShowDialog(this);
pf.test = "test";
pf.Submit += new ParameterForm.ParameterSubmitResult(pf_Submit);
};
definition and use
public partial class ParameterForm : Form
{
public string test;
public XmlElement node;
public delegate void ParameterSubmitResult(object sender, XmlElement e);
public event ParameterSubmitResult Submit;
public void SubmitButton_Click(object sender, EventArgs e)
{
Submit(this,this.node);
Debug.WriteLine(test);
}
}
result:
Submit - null object reference
test - null object reference
pf.ShowDialog(this); is a blocking call, so pf.Submit += new ParameterForm.ParameterSubmitResult(pf_Submit); is never reached: switch the order.
Submit(this,this.node); throws a null object reference because no event is assigned to it (see above). Generally, you should always check first: if (Submit != null) Submit(this,this.node);
You should change ``pf.ShowDialog(this);topf.Show(this);` so that your main form isn't disabled while your dialog box is open, if that's what you want, or use the model below (typical for dialog boxes.)
I'm not sure what pf_Submit is supposed to do, so this might not be the best way to go about it in your application, but it's how general "Proceed? Yes/No" questions work.
Button ParametersButton = new Button();
ParametersButton.Click += delegate
{
ParameterForm pf = new ParameterForm(testString);
pf.ShowDialog(this); // Blocks until user submits
// Do whatever pf_Submit did here.
};
public partial class ParameterForm : Form
{
public string test; // Generally, encapsulate these
public XmlElement node; // in properties
public void SubmitButton_Click(object sender, EventArgs e)
{
Debug.WriteLine(test);
this.Close(); // Returns from ShowDialog()
}
}
When you want to use your second variant, you have to use a getString()-Method, where you can put the e.g. "testString". The way you wrote it, "testString" should be a method (and got brackets).
EDIT (a bit more precise):
You could write:
pf.getString(testString);
, if "pf" is an instance of your own class, otherwise you had to look up, whether you can retrieve a String in this class.
the thing was in line order :)
pf.Submit += new ParameterForm.ParameterSubmitResult(pf_Submit);
and
pf.Test = "test";
should have been set before
pf.ShowDialog(this);
my mistake thingking that parameter can be passed after 2nd form was displayed
thnx for answers
I am currently working on Windows Store App in c#.
Now,
I am having a list box 'Listbox1' which gets its items on a button click event from a text box 'tasks', and have selected Items delete property on other button click event.
private void add_Click(object sender, RoutedEventArgs e)
{
string t;
t = tasks.Text;
if (t != "")
{
Listbox1.Items.Add(t);
}
else
{
var a = new MessageDialog("Please Enter the Task First");
a.Commands.Add(new UICommand("Ok"));
a.ShowAsync();
}
tasks.Text = "";
}
private void del_Click(object sender, RoutedEventArgs e)
{
for (int p = 0; p < Listbox1.SelectedItems.Count; p++)
{
Listbox1.Items.Remove(Listbox1.SelectedItems[p].ToString());
p--;
}
}
Now I want to save this list into local application storage, after user complete the changes (on a button click event perhaps).
And also to send all Listbox Items to another page(s).
I am not much a coder, I design things.
Please guide me by sample or reference.
Thank you in advance :)
If you have already stored the data to local storage, you could just read it in the OnNavigatedTo override of the other page. Otherwise, use the navigation parameter: http://social.msdn.microsoft.com/Forums/windowsapps/en-US/8cb42356-82bc-4d77-9bbc-ae186990cfd5/passing-parameters-during-navigation-in-windows-8
Edit: I am not sure whether you also need some information about local storage. This is easy: Windows.Storage.ApplicationData.Current.LocalSettings has a property called Values, which is a Dictionary you can write your settings to. Have a look at http://msdn.microsoft.com/en-us/library/windows/apps/hh700361.aspx
Edit: Try something like this code to store your list.
// Try to get the old stuff from local storage.
object oldData = null;
ApplicationDataContainer settings = ApplicationData.Current.LocalSettings;
bool isFound = settings.Values.TryGetValue("List", out oldData);
// Save a list to local storage. (You cannot store the list directly, because it is not
// serialisable, so we use the detours via an array.)
List<string> newData = new List<string>(new string[] { "test", "blah", "blubb" });
settings.Values["List"] = newData.ToArray();
// Test whether the saved list contains the expected data.
Debug.Assert(!isFound || Enumerable.SequenceEqual((string[]) oldData, newData));
Note, this is only demo code for testing - it does not make real sense...
Edit: One advice: Do not persist the list in your click handlers as this will become extremely slow as the list grows. I would load and save the list in the Navigation handlers, i.e. add something like
protected override void OnNavigatedTo(NavigationEventArgs e) {
base.OnNavigatedTo(e);
if (this.ListBox1.ItemsSource == null) {
object list;
if (ApplicationData.Current.LocalSettings.Values.TryGetValue("List", out list)) {
this.ListBox1.ItemsSource = new List<string>((string[]) list);
} else {
this.ListBox1.ItemsSource = new List<string>();
}
}
}
protected override void OnNavigatedFrom(NavigationEventArgs e) {
if (this.ListBox1.ItemsSource != null) {
ApplicationData.Current.LocalSettings.Values["List"] = this.ListBox1.ItemsSource.ToArray();
}
base.OnNavigatedFrom(e);
}
Here is very nice simple example on SQLite DataBase Use in winRT app Development. Look at it and you will know how you can store your Data on the Local Machine. I learned Basic code from this example.
http://blogs.msdn.com/b/robertgreen/archive/2012/11/13/using-sqlite-in-windows-store-apps.aspx
Now, for ease of navigation let me suggest you a flow for this portion of your app.
take one ObservableCollection<> of string and store values of
that textBox into this ObservationCollection with onClick() and then
refer that ObservableCollection<String> to the ItemsList of the
listBox.
now at the time you need to send your Data to the next page, make one parameterised constructor of next page and pass that ObservableCollection<String> as it's parameter.
Now you can access those Data in your constructor and can use as however you want.
Hope this will help..
I'm trying to create a page where you get an overview of the sponsors of the project, the data is fetched from the database with the following service:
[OperationContract]
public IEnumerable<Sponsor> getSponsors()
{
var query = (from p in dc.Sponsors select p);
IEnumerable<Sponsor> i = query;
return i;
}
When I put my breakpoint on the i I can see that the data is correctly in there.
In my Sponsorspage I do the following
public partial class Sponsorspage : UserControl
{
IEnumerable<Sponsor> sponsors = null;
public Sponsorspage()
{
SponsorsServiceClient client = new SponsorsServiceClient();
client.getSponsorsCompleted +=new EventHandler<getSponsorsCompletedEventArgs>(client_getSponsorsCompleted);
client.getSponsorsAsync();
InitializeComponent();
}
void client_getSponsorsCompleted(object sender, getSponsorsCompletedEventArgs e)
{
if (e.Error != null)
MessageBox.Show(e.Error.ToString());
else
{
sponsors = e.Result;
foreach (Sponsor s in sponsors)
{
SponsorView control = new SponsorView(s.tekst);
SLWrapPanel.Children.Add(control);
}
}
}
For each sponsor in the database, I create the Sponsorview to which I give the source and text. You can see the code for my Sponsorview here.
public partial class SponsorView : UserControl
{
public SponsorView(string tekst)
{
txtSponsor.Text = tekst;
//Uri uri = new Uri(imageSource, UriKind.Relative);
//ImageSource imgSource = new BitmapImage(uri);
//imgSponsor.Source = imgSource;
InitializeComponent();
}
}
But when I run the page, I get the following error:
Object reference not set to an instance of an object.
at OndernemersAward.Views.SponsorView..ctor(String tekst)
at OndernemersAward.Views.Sponsorspage.client_getSponsorsCompleted(Object sender, getSponsorsCompletedEventArgs e)
at OndernemersAward.SponsorsServiceReference.SponsorsServiceClient.OngetSponsorsCompleted(Object state)
What I'm trying to do is give information (here string tekst) from the sponsor s to my user control, which it then uses to fill a textblock. Am I doing this wrong or?
Thanks! :)
Well, you're trying to iterate over results that you are supposed to hold in sponsors variable. However, please note that you're calling asynchronus version (and the only one available in Silverlight, as I recall) of getSponsors method. What it means is, you will not get results immediately after calling service method, but instead you need to wait until event with completed execution will be called.
I don't know why such thing could create some problems with debug, but it's definitely error in code that could result in problems with showing the page.
Here is very simple example on how you should retrieve result from service. Hope this will help you notice error in your approach.
I'm beginner with C# and wp7 platform and I have some problem with good idea to get request from web service.
I made webservice in PHP (nusoap - WSDL) and everything is working fine in "normal" using.
Now I have ObservableCollection saved in IsolatedStorage with I load when Page is open (List of watched stacks exchange). Then I want to refresh data for every item from web service.
I don't know whether this is a good idea.
Code:
private GPWWebservicePortTypeClient client = new GPWWebservicePortTypeClient();
private ObservableCollection<WebServiceClass.ItemGetValues> StoredStock =
new ObservableCollection<WebServiceClass.ItemGetValues>();
public const string _fileName = "listaObserwowanych.xml";
public Page()
{
InitializeComponent();
DataContext = App.ViewModel;
this.Loaded += new RoutedEventHandler(Page_Loaded);
client.GetLastValueCompleted +=
new EventHandler<GetLastValueCompletedEventArgs>(client_GetLastValueCompleted);
foreach (var itemGetValuese in App.ViewModel.Items)
{
client.GetLastValueAsync(itemGetValuese.name);
}
var o =
Observable.FromEvent<GetLastValueCompletedEventArgs(client,"GetLastValueCompleted")
.Subscribe(setList);
}
void client_GetLastValueCompleted(object sender, GetLastValueCompletedEventArgs e)
{
if (e.Error != null)
{
MessageBox.Show(Convert.ToString(e.Error));
}
else
{
ObservableCollection<WebServiceClass.ItemGetValues> ListValues =
(ObservableCollection<WebServiceClass.ItemGetValues>)
JsonConvert.DeserializeObject(e.Result,
typeof(ObservableCollection<WebServiceClass.ItemGetValues>));
StoredStock.Add(ListValues[0]);
}
}
private void setList(IEvent<GetLastValueCompletedEventArgs> ex)
{
List.ItemsSource = StoredStock;
}
void Page_Loaded(object sender, RoutedEventArgs e)
{
App.ViewModel.LoadData();
List.ItemsSource = App.ViewModel.Items;
}
Like u see I use RX to call method client_GetLastValueCompleted add store result to auxiliary variable (StoredStock). Then refresh List in setList method, but that method is client_GetLastValueCompleted what is not soo good idea, becouse I need to run that method only when all of runned GetLastValueAsync in foreach is completed.
Second problem: becouse of async web service method StoredStock sometime have different order than App.ViewModel.Items .
Any good idea how to do that in right way?
Best regards,
Lukas
You're really mixing up a number of ways to call web services and Rx. You really need to decide on a single way and stick to it.
If you're going to use Rx, then you'll have something like this:
public Page()
{
InitializeComponent();
DataContext = App.ViewModel;
this.Loaded += new RoutedEventHandler(Page_Loaded);
}
void Page_Loaded(object sender, RoutedEventArgs e)
{
App.ViewModel.LoadData();
var storedStock =
new ObservableCollection<WebServiceClass.ItemGetValues>();
List.ItemsSource = storedStock;
var values =
Observable.Using<WebServiceClass.ItemGetValues, GPWWebservicePortTypeClient>
(() => new GPWWebservicePortTypeClient(), ws =>
{
var clientGetLastValue = Observable
.FromAsyncPattern<string, GetLastValueResponse>
(ws.BeginGetLastValue, ws.EndGetLastValue);
Func<string, WebServiceClass.ItemGetValues> deserializeFirst = r =>
((List<WebServiceClass.ItemGetValues>)JsonConvert
.DeserializeObject(r,
typeof(List<WebServiceClass.ItemGetValues>)))
.First();
return
from item in App.ViewModel.Items
from e in clientGetLastValue(item)
select deserializeFirst(e.Result);
});
values.Subscribe(storedStock.Add);
}
You'll have to get the right method call names for your web service client, but the code should roughly be right. Let me know how you go.
I corrected the code above. Should have returned the query inside the Using call rather than assign it to values.
I corrected the call to FromAsyncPattern to use the correct method names and return type from the actual web service reference class sent via email.
It should look like this:
Observable.FromAsyncPattern<string, GetLastValueResponse>
(ws.BeginGetLastValue, ws.EndGetLastValue);
If you're a beginner with C#, try to avoid RX for the time being. It is a cool technology, but if you use it without clear understanding of what is going on, it will bring more problems than solve.
Use a simple event, and when each async item arrives, locate and update the correspondent one in the stored list.