I'm creating a simple WPF application that needs to display/Edit data from SQL server using Entity Framework Model. I created a small test window to see how things work and i noticed that property changed events and data validation are kind of automatically implemented. here's my xaml:
<Style TargetType="{x:Type Button}">
<Setter Property="IsEnabled" Value="False"/>
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding ElementName=txtRibbonCoreSize,Path=(Validation.HasError)}" Value="False"/>
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="True"/>
</MultiDataTrigger>
</Style.Triggers>
</Style>
<StackPanel>
<ac:AutoCompleteBox x:Name="txtPrn1" Width="250" HorizontalAlignment="Left"
ValueMemberBinding="{Binding Converter={StaticResource prnC}}"
FilterMode="Contains"
ItemsSource="{Binding PrinterParams}">
<ac:AutoCompleteBox.TextBoxStyle>
<Style TargetType="TextBox">
<Setter Property="FocusManager.FocusedElement"
Value="{Binding RelativeSource={RelativeSource Self}}" />
</Style>
</ac:AutoCompleteBox.TextBoxStyle>
<ac:AutoCompleteBox.ItemTemplate>
<DataTemplate>
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="{}{0} - {1}">
<Binding Path="Manufacturer"/>
<Binding Path="Model"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</DataTemplate>
</ac:AutoCompleteBox.ItemTemplate>
</ac:AutoCompleteBox>
<TextBox Text="{Binding ElementName=txtPrn1,Path=SelectedItem.MHeight,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
<Button x:Name="btn1" Content="Accept" Click="btn1_Click"/>
</StackPanel>
and here's my code:
//instance of EF datamodel object
DbEntities db = new DbEntities();
private void Window_Loaded(object sender, RoutedEventArgs e)
{
DataContext = db;
}
private void btn1_Click(object sender, RoutedEventArgs e)
{
db.SaveChanges();
}
MHeight is an integer and if i put a non integer value in the textbox it's borders becomes red and the button becomes disabled (according to the validation style above). if i click on the button the new data is saved correctly.
does the EF model implements the INotifyPropertyChanged and the IDataErrorInfo interfaces?
For the INotifyPropertyChanged
yes it's already implemented , but IDataErrorInfo
you have to implement it your self.
Your Entities inherit from EntityObject
which it self inherits from StructuralObject
which finally implements INotifyPropertyChanged