putting multibinding on a single line in xaml

Question

Is there a way to take this multibinding:

<TextBox.IsEnabled>
    <MultiBinding Converter="{StaticResource LogicConverter}">
        <Binding ElementName="prog0_used" Path="IsEnabled" />
        <Binding ElementName="prog0_used" Path="IsChecked" />
    </MultiBinding>
</TextBox.IsEnabled>

and put is all on one line, as in <TextBox IsEnabled="" />?

If so, where can I learn the rules of this formattiong?

Manna

I don't believe this is possible, but I'm interested to know. – Overexpose

bind it directly to prog0_used with your custom converter prog0_used-to-boolean ? – Jaleesa

Answer 1

A better (and simpler) approach would be to define a style as a resource which you can easily apply to any TextBox:

<Window.Resources>
    <c:MyLogicConverter x:Key="LogicConverter" />

    <Style TargetType="{x:Type TextBox}" BasedOn="{StaticResource {x:Type TextBox}}" x:Key="MultiBound">
        <Setter Property="IsEnabled">
            <Setter.Value>
                <MultiBinding Converter="{StaticResource LogicConverter}">
                    <Binding ElementName="switch" Path="IsEnabled" />
                    <Binding ElementName="switch" Path="IsChecked" />
                </MultiBinding>
            </Setter.Value>
        </Setter>
    </Style>
</Window.Resources>

<StackPanel Orientation="Horizontal">
    <CheckBox Name="switch" />
    <TextBox Name="textBox2" Text="Test" Style="{StaticResource MultiBound}" />
</StackPanel>

Lalise

Answer 2

This can be done with a custom markup extension:

public class MultiBinding : System.Windows.Data.MultiBinding
{
    public MultiBinding (BindingBase b1, BindingBase b2)
    {
        Bindings.Add(b1);
        Bindings.Add(b2);
    }

    public MultiBinding (BindingBase b1, BindingBase b2, BindingBase b3)
    {
        Bindings.Add(b1);
        Bindings.Add(b2);
        Bindings.Add(b3);
    }

    // Add more constructors if you need.
}

Usage:

<TextBox IsEnabled="{local:MultiBinding
    {Binding IsEnabled, ElementName=prog0_used},
    {Binding IsChecked, ElementName=prog0_used},
    Converter={StaticResource LogicConverter}}">

Taliataliaferro

Removed comment and created a new answer. – Alica

Can be done with one constructor using the params keyword: public MultiBinding (params BindingBase[] bindings) – Augean

This is a great solution! And gets around the xaml issues of the built in Multibinding. Thanks for this – Solferino

@BalintPogatsa That was my first thought as well, but the params keyword doesn't appear to work here - compilation fails with error MC3009: Cannot find a public constructor for 'MultiBinding' that takes 2 arguments.. Have you gotten it to work with this method; and if so, how? – Postdoctoral

Answer 3

For MultiBinding there is no shorthand string. You need to use the expanded element syntax.

Windrow

Answer 4

I tried using Discord's answer, but it didn't work right out of the box. To make it work I added a new constructor:

public class MultiBinding : System.Windows.Data.MultiBinding
{
    public MultiBinding(BindingBase b1, BindingBase b2, object converter)
    {
        Bindings.Add(b1);
        Bindings.Add(b2);
        Converter = converter as IMultiValueConverter;
    }
}

Usage will then be like this:

    <TextBox IsEnabled="{local:MultiBinding {Binding IsEnabled, ElementName=prog0_used}, 
{Binding IsChecked, ElementName=prog0_used}, 
{StaticResource LogicConverter}}">

Alica

I'd like to accomplish this since I have so many controls that need to react to multiple booleans, but mine's not behaving: #37058220 – Suffumigate