I have two separate converters for visibility, one based on whether a field has been updated and one based on whether a field is allowed to be seen. I use the updatedField one for each text item on my page so that a star shows up next to an updated field. But some text items only are visible to some users based on permission levels.
For example:
<Image Visibility="{Binding ElementName=MyObject, Path=UpdatedFields, Mode=OneWay, Converter={StaticResource updatedFieldConverter}, ConverterParameter=FieldToTest}" Source="Properties:Resources.star_yellow" />
and
<TextBlock FontSize="21" Foreground="{DynamicResource LabelBrush}" Text="{x:Static Properties:Resources.Some_Text}" Visibility="{Binding Source={StaticResource allowedFields}, Path=Some_Text_Field, Converter={StaticResource visibilityConverter}}" />
My problem is that for the case of the permission-required fields I need to run both converters to determine if the star shows up. Is there a way to do a boolean "And" on the results of two converters?
I looked at this post but it doesn't seem to allow for different sets of parameters to be passed into to the two different converters.
-------Update--------
I also tried to create a MultiValueConverter with this xaml
<Image Grid.Row="4" Grid.Column="0" Source="star_yellow.png">
<Image.Visibility>
<MultiBinding Converter="{StaticResource combinedVisibilityConverter}" ConverterParameter="FieldToTest" >
<Binding ElementName="allowedFieldsModel" Path="Some_Text_Field" Mode="OneWay" />
<Binding ElementName="MyObject" Path="UpdatedFields" Mode="OneWay" />
</MultiBinding>
</Image.Visibility>
</Image>
But when it enters the converter both values are "DependencyProperty.UnsetValue". So I'm apparently doing something wrong here.
--------Solution---------
I had to modify to this, but then it worked.
<Image.Visibility>
<MultiBinding Converter="{StaticResource combinedVisibilityConverter}" ConverterParameter="FieldToTest">
<Binding Source="{StaticResource allowedFieldsModel}" Path="Some_Text_Field" />
<Binding Path="MyObject.UpdatedFields" />
</MultiBinding>
</Image.Visibility>
You could use a MultiBinding together with a short, hand made IMultiValueConverter.
Example:
<StackPanel>
<StackPanel.Resources>
<local:MultiBooleanToVisibilityConverter x:Key="Converter" />
</StackPanel.Resources>
<CheckBox x:Name="Box1" />
<CheckBox x:Name="Box2" />
<TextBlock Text="Hidden Text">
<TextBlock.Visibility>
<MultiBinding Converter="{StaticResource Converter}">
<Binding ElementName="Box1"
Path="IsChecked" />
<Binding ElementName="Box2"
Path="IsChecked" />
</MultiBinding>
</TextBlock.Visibility>
</TextBlock>
</StackPanel>
... and the converter ...
class MultiBooleanToVisibilityConverter : IMultiValueConverter
{
public object Convert(object[] values,
Type targetType,
object parameter,
System.Globalization.CultureInfo culture)
{
bool visible = true;
foreach (object value in values)
if (value is bool)
visible = visible && (bool)value;
if (visible)
return System.Windows.Visibility.Visible;
else
return System.Windows.Visibility.Hidden;
}
public object[] ConvertBack(object value,
Type[] targetTypes,
object parameter,
System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}