Binding UI Element Dependency Property with a Data Member of class - silverlight-4.0

Question

I need to bind all the check boxes(IsChecked Property) in an StackPannel with a bool value which is defined in a class. Attaching my Xaml with my question, please help
<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<StackPanel Height="287" HorizontalAlignment="Left" Margin="78,65,0,0" Name="stackPanel1" VerticalAlignment="Top" Width="309" DataContext="checkFlag">
<CheckBox Content="" Height="71" Name="checkBox1" IsChecked="{Binding Path=Binding.MainPage,Source=checkFlag,Mode=TwoWay}"/>
<CheckBox Content="" Height="71" Name="checkBox2" IsChecked="{Binding Path=Binding.MainPage,Source=checkFlag,Mode=TwoWay}"/>
</StackPanel>
<Button Content="Button" Height="72" HorizontalAlignment="Left" Margin="78,400,0,0" Name="button1" VerticalAlignment="Top" Width="160" Click="button1_Click" />
<Button Content="Button" Height="72" HorizontalAlignment="Left" Margin="227,400,0,0" Name="button2" VerticalAlignment="Top" Width="160" Click="button2_Click" />
The checkboxes are not getting check/uncheck on set/reset of checkFlag. Should i implement "INotifyPropertyChanged" for the flag Or something else. Adding the class behind also, Please have a look.'
namespace Binding
{
public partial class MainPage : PhoneApplicationPage
{
public bool checkFlag;
// Constructor
public MainPage()
{
InitializeComponent();
}
private void button1_Click(object sender, RoutedEventArgs e)
{
checkFlag = true;
}
private void button2_Click(object sender, RoutedEventArgs e)
{
checkFlag = false;
}
}

Answer 1

it looks to me like you need to implement, as you guess, INotifyPropertyChanged here is a link to the MSDN documentation
here is some demo code....
public class MyData : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void RaisePropertyChanged(string property)
{
PropertyChangedEventArgs args = new PropertyChangedEventArgs(property);
var handler = this.PropertyChanged;
if (handler != null)
{
handler(this, args);
}
}
int _someInt = 0;
public int SomeInt
{
get { return _someInt ;}
set { if ( value == _someInt ) return;
_someInt = value;
RaisePropertyChanged("SomeInt");
}
}
string _someString = string.Empty;
public string SomeString
{
get { return _someString ;}
set { if ( value == _someString ) return;
_someString = value;
RaisePropertyChanged("SomeString ");
}
}
}
you set up your private variables, then add a property for each one you want to expose.
in the getter, just return the value... in the setter, check if the value has changed and if so assign the value and raise the property changed event. make sure that the name you are passing in as a string is the same as the property... same capitalization, same spelling, etc.