Cant Make instances with usercontrol

[yogeshg]

In Windows Phone7 I created an UserControl in which I am parsing some Data. Now I am not able to make instances of that Usercontrol.If I drag n drop the usercontrol the error occurs.

When I remove parsing from the Usercontrol I am able to make instances unless I am getting error such as

`"Cannot create instance of '<usercontrolname>' 
"XapCannotFindFileInPackage]
Arguments:HelpScreenData.xml 
Debugging Resource String are unavailable.Often the key and
arguments provide sufficient information to diagonise the problem.see
http://go.microsoft.com'/fwlink/?linkid=106663&version5.0.10411.00&
file=system.xml.dll&key=Xml_cannot find file in Xappackage"

And my UserControl is

public partial class ques : UserControl
{
    Popup popup = new Popup();
    tutorial tut = new tutorial();   //another usercontrol

    String[] str;
    String[] nam;
    public ques()
    {
        InitializeComponent();

   }
 private void UserControl_Loaded(object sender, RoutedEventArgs e)
    {

        LayoutRoot.Visibility = Visibility.Visible;

        buy_bac.Visibility = Visibility.Collapsed;
        buy_hme.Visibility = Visibility.Collapsed;
        buy_qestim.Visibility = Visibility.Collapsed;
        buy_piti.Visibility = Visibility.Collapsed;
        buy_qual.Visibility = Visibility.Collapsed;
        buy_rent.Visibility = Visibility.Collapsed;
        buy_rep.Visibility = Visibility.Collapsed;
        buy_mre.Visibility = Visibility.Collapsed;

        if (Modules.Programname == "Buyers")
        {
            buy_bac.Visibility = Visibility.Visible;
            buy_hme.Visibility = Visibility.Visible;
            buy_qestim.Visibility = Visibility.Visible;
            buy_piti.Visibility = Visibility.Visible;
            buy_qual.Visibility = Visibility.Visible;
            buy_rent.Visibility = Visibility.Visible;
            buy_rep.Visibility = Visibility.Visible;
            buy_mre.Visibility = Visibility.Visible;
        }
        XDocument doc = XDocument.Load("HelpScreenData.xml");
        string val = doc.ToString();

        XElement doc1 = doc.Descendants("buyer").First();

        var parsedPlist = doc1.Descendants("row");

        int i = 0;
        str = new string[parsedPlist.Count()];
        nam = new string[parsedPlist.Count()];
        foreach (XElement elem in parsedPlist)
        {
            nam[i] = (string)elem.Element("btn_name");
            str[i] = (string)elem.Element("string");
            i++;
        }
    }
    private void i1_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {


        if (nam[0] == buy_bac.Name)
        {


            Modules.msg = str[0];
            if (Modules.msg != null)
            {
                if (popup.IsOpen != true)
                {

                    popup.Child = tut;
                    popup.IsOpen = true;
                    popup.VerticalOffset = 200;
                    popup.HorizontalOffset = 50;
                    popup.IsOpen = true;
                    tut.lb_tut.Text = Modules.msg;
                }
                else
                {
                    popup.IsOpen = false;
                }
            }
            else if (nam[1] == buy_hme.Name)
            {
                Modules.msg = str[1];
                if (Modules.msg != null)
                {
                    if (popup.IsOpen != true)
                    {
                        popup.Child = tut;
                        popup.IsOpen = true;
                        popup.VerticalOffset = 400;
                        popup.HorizontalOffset = 50;
                        popup.IsOpen = true;
                        tut.lb_tut.Text = Modules.msg;
                    }
                    else
                    {
                        popup.IsOpen = false;
                    }
                }

            }
            else if (nam[1] == buy_qestim.Name)
            {
                Modules.msg = str[2];
                if (Modules.msg != null)
                {
                    if (popup.IsOpen != true)
                    {
                        popup.Child = tut;
                        popup.IsOpen = true;
                        popup.VerticalOffset = 400;
                        popup.HorizontalOffset = 50;
                        popup.IsOpen = true;
                        tut.lb_tut.Text = Modules.msg;
                    }
                    else
                    {
                        popup.IsOpen = false;
                    }
                }

            }
        }


    }

    private void i3_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        if (nam[2] == buy_piti.Name)
        {
            Modules.msg = str[3];
            if (Modules.msg != null)
            {
                if (popup.IsOpen != true)
                {
                    popup.Child = tut;
                    popup.IsOpen = true;
                    popup.VerticalOffset = 600;
                    popup.HorizontalOffset = 50;
                    popup.IsOpen = true;
                    tut.lb_tut.Text = Modules.msg;
                }
                else
                {
                    popup.IsOpen = false;
                }
            }

        }
        else if (nam[2] == buy_rent.Name)
        {
            Modules.msg = str[4];
            if (Modules.msg != null)
            {
                if (popup.IsOpen != true)
                {
                    popup.Child = tut;
                    popup.IsOpen = true;
                    popup.VerticalOffset = 600;
                    popup.HorizontalOffset = 50;
                    popup.IsOpen = true;
                    tut.lb_tut.Text = Modules.msg;
                }
                else
                {
                    popup.IsOpen = false;
                }
            }

        }
        else if (nam[2] == buy_qual.Name)
        {
            Modules.msg = str[5];
            if (Modules.msg != null)
            {
                if (popup.IsOpen != true)
                {
                    popup.Child = tut;
                    popup.IsOpen = true;
                    popup.VerticalOffset = 600;
                    popup.HorizontalOffset = 50;
                    popup.IsOpen = true;
                    tut.lb_tut.Text = Modules.msg;
                }
                else
                {
                    popup.IsOpen = false;
                }
            }

        }
        else if (nam[2] == buy_mre.Name)
        {
            Modules.msg = str[6];
            if (Modules.msg != null)
            {
                if (popup.IsOpen != true)
                {
                    popup.Child = tut;
                    popup.IsOpen = true;
                    popup.VerticalOffset = 600;
                    popup.HorizontalOffset = 50;
                    popup.IsOpen = true;
                    tut.lb_tut.Text = Modules.msg;
                }
                else
                {
                    popup.IsOpen = false;
                }
            }

        }
    }

The XML Parsed is

<?xml version="1.0" encoding="utf-8" ?>
<plist version="1.0">
<Main_Screen>
<row>
<btn_name>Buyer Programs</btn_name>
<string>Answer your client’s difficult .</string>
</row>
<row>
<btn_name>Seller’s Programs</btn_name>
<string>What do sellers want s needs.</string>
</row>
</Main_Screen>
<abssas>
<row>
<btn_name>dat Programs</btn_name>
<string> your client’s </string>
</row>
<row>
<btn_name>my Programs</btn_name>
<string> sellers want s needs.</string>
</row>
</abssas>
</plist>

What is the problem with this?

[joaocardoso]

The xml file is included on your project? Is it Build Action as "Content"?

[yogeshg]

yess.I tried it did not work.

[joaocardoso]

yess.I tried it did not work.

Can you provide a sample project? I dont seem to be able to replicate your problem.

[izinin]

Hi yougeshg,

You shall not have any operation that may throw exception in UserControl constructor. This lines i think make troubles:

    Popup popup = new Popup();
    tutorial tut = new tutorial();   //another usercontrol

If you like to create a child control tree , do it in onLoaded event not in the constructor. This construction works nice in Designer view for me. Also you can check Troubleshooting WPF and Silverlight Designer Load Failures

XAML:
         <UserControl x:Class="jailbreaker.BoardControl"
           Loaded="OnLoad">

            <controls:PivotItem Header="Start">
                <Grid>
                    <my:BoardControl />
                </Grid>
            </controls:PivotItem>
CS:
       public BoardControl()
        {
            InitializeComponent();
        }

        void OnLoad(object sender, RoutedEventArgs e)
        {
            try
            {
                accelerometer = new Accelerometer();
                timer = new DispatcherTimer();
//...................
                accelerometer.Start();
                timer.Start();
            }
            catch (Exception ignore)
            {
            }
        }

do not forget to suppress possible exception in Designer surface with try/catch block , see above

[manikantan]

Hi,
you can use my article as a reference.
http://www.developer.nokia.com/Commu..._Windows_Phone
Examine the header of the MainPage.xaml to see if you have a link to the custom usercontrol you have created.

[izinin]

Hi manikantan

The problem is not in creating and use UserControl . Sometimes WPF designer preview pane is not able to render your application page because your UserControl implementation does not follow design guide "Writing Code for Design Time". In that case WPF designer and application running on device or emulator behaves differently., your application is not broken but you cannot use the page preview

Regards,
Igor