Why my WP emulator stops on splashscreen - silverlight-4.0

Question

I created a WP Class Library BusinessLogic project which is composed by these three class
1) Bottle Class
namespace BusinessLogic
{
public class Bottle : INotifyPropertyChanged
{
// Due to INotifyPropertyChanged interface
public event PropertyChangedEventHandler PropertyChanged;
// Proprietà Title
private string title;
public string Title
{
set
{
if (title != value)
{
title = value;
OnPropertyChanged("Title");
}
}
get
{
return title;
}
}
// Proprietà PhotoFileName
private string photoFileName;
public string PhotoFileName
{
set
{
if (photoFileName != value)
{
photoFileName = value;
OnPropertyChanged("PhotoFileName");
}
}
get
{
return photoFileName;
}
}
protected virtual void OnPropertyChanged(string propChanged)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propChanged));
}
}
}
2) Bottles Class
namespace BusinessLogic
{
public class Bottles : INotifyPropertyChanged
{
// Due to INotifyPropertyChanged interface
public event PropertyChangedEventHandler PropertyChanged;
// Proprietà MainTitle
private string mainTitle;
public string MainTitle
{
set
{
if (mainTitle != value)
{
mainTitle = value;
OnPropertyChanged("MainTitle");
}
}
get
{
return mainTitle;
}
}
// Proprietà bottles
private ObservableCollection<Bottle> bottleSet = new ObservableCollection<Bottle>();
public ObservableCollection<Bottle> BottleSet
{
set
{
if (bottleSet != value)
{
bottleSet = value;
OnPropertyChanged("BottleSet");
}
}
get { return bottleSet; }
}
protected virtual void OnPropertyChanged(string propChanged)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propChanged));
}
}
}
3) BottlesPresenter Class
namespace BusinessLogic
{
public class BottlesPresenter : INotifyPropertyChanged
{
// Due to INotifyPropertyChanged interface
public event PropertyChangedEventHandler PropertyChanged;
// Proprietà BottleMatrix
private Bottles bottlesMatrix;
public Bottles BottlesMatrix
{
protected set
{
if (bottlesMatrix != value)
{
bottlesMatrix = value;
OnPropertyChanged("BottlesMatrix");
}
}
get { return bottlesMatrix; }
}
public BottlesPresenter()
{
XmlSerializer xml = new XmlSerializer(typeof(Bottles));
using (StreamReader fileReader = new StreamReader(#"C:\Stuff\WindowsPhone\AppLearningHowTo2\AppLearningHowTo2\DAL\DB.xml"))
{
BottlesMatrix = (Bottles)xml.Deserialize(fileReader);
}
}
protected virtual void OnPropertyChanged(string propChanged)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propChanged));
}
}
}
The BottlePresenter constructor should deserialize from an xml file located into the file system. It contains the following tags
<?xml version="1.0"?>
<Bottles xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<MainTitle>MainTitle</MainTitle>
<Bottleset>
<Bottle>
<Title>Title1</Title>
<PhotoFileName>PhotoFileName1</PhotoFileName>
</Bottle>
<Bottle>
<Title>Title2</Title>
<PhotoFileName>PhotoFileName2</PhotoFileName>
</Bottle>
</Bottleset>
</Bottles>
Then I created a WP Application and I made a reference to the BusinessLogic.dll project library.
In the MainPage.xaml file I put the XML namespace declaration
xmlns:businesslogic="clr-namespace:BusinessLogic;assembly=BusinessLogic"
I then instantiated the BottlesPresenter class in the MainPage.xaml Resources collection
<phone:PhoneApplicationPage.Resources>
<businesslogic:BottlesPresenter x:Key="bottlesPresenter" />
</phone:PhoneApplicationPage.Resources>
And finally put a TextBlock in the content area with a binding to that resource:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<TextBlock HorizontalAlignment="Center"
VerticalAlignment="Center"
Text="{Binding Source={StaticResource bottlesPresenter},
Path=Bottles.MainTitle}" />
Unfortunately I launch the debugger, the emulator switch on, reach the splashscreen and doesn't go on.
In a nutshell: I can't reach to create an instance of the BottlesPresenter class.
I banged my head against the wall for weeks without finding a solution.
Please could someone give me a hand?
Thank you very much
Antonio

Answer 1

Emulator behaves like that when WP7 cannot construct Application object. From question, I see only 1 reference from Application to your code. It's BottlePresenter in Resources.
XamlLoader tries to create instance of this type.
See what's inside your BottlePresenter constructur:
public BottlesPresenter()
{
XmlSerializer xml = new XmlSerializer(typeof(Bottles));
using (StreamReader fileReader = new StreamReader(
#"C:\Stuff\WindowsPhone\AppLearningHowTo2\AppLearningHowTo2\DAL\DB.xml"))
{
BottlesMatrix = (Bottles)xml.Deserialize(fileReader);
}
}
First line is OK.
Second line is OK.
Third line causes exception, because path "C:\Stuff\WindowsPhone\AppLearningHowTo2\AppLearningHowTo2\DAL\DB.xml" is not acceptable on Windows Phone.
All files you can access is Content of your XAP, Resources in your assembly, and files in Isolated Storage.
Following articles might help you All about WP7 Isolated Storage - Read and Save Text files