Question

I am working in Silverlight4 VS 2010.I have placed a CheckBox in my .xaml file. I need it’s DataContextChanged event. But unfortunately i didn’t find it.

Here is my CheckBox :

<CheckBox x:Name="chkRegion" Content="{Binding name}" Click="CheckBox_Click" ></CheckBox>

Could you please help me in to find DataContextChanged in SL 4 VS 2010.

Thanks, Rajbir

Answer 1

Implement an Converter (its just a simple class which gets derived from IValueConverter and implement the interface methods)

public class ChangeIsCheckedValConverter : IValueConverter
{
    public object Convert(object value,
                          Type targetType,
                          object parameter,
                          System.Globalization.CultureInfo culture)
    {
        if (value != null)
        {

//value here is the object which you are binding to the DataContext of
Checkbox ; //return the bool (true or false) based on your valued
binded to your checkbox

    }

    public object ConvertBack(object value,
                              Type targetType,
                              object parameter,
                              System.Globalization.CultureInfo culture)
    {
        return null;
    }

You will have to add the name space of you newly implemnted converter whereever you will want to use .

Then use this converter where your checkbox is defined in datatemplate as below :
//First define the key as below :

 <converters:VisibilityConverter x:Key="changeConverter" />

<CheckBox x:Name="chkRegion" Content="{Binding name}" IsChecked={Binding ,Converter={StaticResource changeConverter}}"} Click="CheckBox_Click" ></CheckBox>