Any way to reuse Bindings in WPF?

Question

I'm getting to the point in a WPF application where all of the bindings on my controls are getting quite repetitive and also a little too verbose. Also if I want to change this binding I would have to change it in various places instead of just one.

Is there any way to write the source part of the binding once such as in a resource and then reuse it by referencing it with a more compact syntax. I've looked around for such capabilities but I haven't found it.

What I'm doing now

<StackPanel>
    <ToggleButton x:Name="someToggleButton" />
    <Button Visibility="{Binding ElementName=someToggleButton, Path=IsChecked, Converter={StaticResource BoolToVisibilityConverter}}" />
    <Grid Visibility="{Binding ElementName=someToggleButton, Path=IsChecked, Converter={StaticResource BoolToVisibilityConverter}}" />
    <TextBox Visibility="{Binding ElementName=someToggleButton, Path=IsChecked, Converter={StaticResource BoolToVisibilityConverter}}" />
    <CheckBox Visibility="{Binding ElementName=someToggleButton, Path=IsChecked, Converter={StaticResource BoolToVisibilityConverter}}" />
</StackPanel>

What I want to be able to do (Pseudocode)

<StackPanel>
    <StackPanel.Resources>
        <Variable x:Name="someToggleButtonIsChecked" 
                  Type="{x:Type Visibility}"  
                  Value="{Binding ElementName=someToggleButton, Path=IsChecked, Converter={StaticResource BoolToVisibilityConverter}}" />
    </StackPanel.Resources>

    <ToggleButton x:Name="someToggleButton" />
    <Button Visibility="{VariableBinding someToggleButtonIsChecked}" />
    <Grid Visibility="{VariableBinding someToggleButtonIsChecked}" />
    <TextBox Visibility="{VariableBinding someToggleButtonIsChecked}" />
    <CheckBox Visibility="{VariableBinding someToggleButtonIsChecked}" />
</StackPanel>

Is there any similar type of similar feature or technique that will allow me to declare the binding source once and then reuse it?

Answer 1

You can just bind someToggleButton's IsChecked property to a property on your viewmodel (the DataContext) and use that. It would look something like this:

<StackPanel>  
<ToggleButton x:Name="someToggleButton" IsChecked="{Binding ToggleVisibility, Mode=TwoWay, Converter={StaticResource BoolToVisibilityConverter}}"   /> 
<Button Visibility="{Binding ToggleVisibility}" /> 
<Grid Visibility="{Binding ToggleVisibility}" /> 
<TextBox Visibility="{Binding ToggleVisibility}" /> 
<CheckBox Visibility="{Binding ToggleVisibility}" /> 
</StackPanel> 

This would require that your Window's DataContext has a property called ToggleVisibility of type Visibility.

EDIT:

To eleborate further, your viewmodel could look like this:

public class SomeViewModel : INotifyPropertyChanged
{

    private Visibility toggleVisibility;

    public SomeViewModel()
    {
        this.toggleVisibility = Visibility.Visible;
    }

    public Visibility ToggleVisibility
    {
        get
        {
            return this.toggleVisibility;
        }
        set
        {
            this.toggleVisibility = value;
            RaisePropertyChanged("ToggleVisibility");
        }
    }

    private void RaisePropertyChanged(string propertyName)
    {
        if (this.PropertyChanged != null)
            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }

    #region INotifyPropertyChanged Members

    public event PropertyChangedEventHandler PropertyChanged;

    #endregion
}

And you would then set an instance of it as the DataContext on the Window or even just on the StackPanel

Answer 2

Is there any way to write the source part of the binding once such as in a resource and then reuse it by referencing it with a more compact syntax.

Perhaps you can do that with PyBinding. I don't know the extent of its capabilities, but I use it all the time ot avoid type converters. Here is an example I use a lot.

Visibility="{p:PyBinding BooleanToVisibility(IsNotNull($[.InstanceName]))}"

• BooleanToVisibility is a function I wrote in IronPython.
• $[.InstanceName] binds to the InstanceName property of the current data-bound item.

EDIT: You can also use this to bind one UI's property to another's. Here is some info from the help file.

• $[NameTextBlock.Text] - The text property of the element with x:Name equal to "NameTextBlock"
• $[NameTextBlock] - An actual TextBlock instance, rather than one of its properties
• $[{Self}] - Bind to your self. Equivalent to {Binding RelativeSource={RelativeSource Self}}
• $[{Self}.Text] - The Text property off your self. Equivalent to {Binding Path=Text, RelativeSource={RelativeSource Self}}

http://pybinding.codeplex.com/

Untested Theory

<StackPanel> 
    <ToggleButton x:Name="someToggleButton" /> 
    <Button Visibility="{p:PyBinding BooleanToVisibility($[someToggleButton.IsChecked])}" /> 
    <Grid Visibility="{p:PyBinding BooleanToVisibility($[someToggleButton.IsChecked])}"/> 
    <TextBox Visibility="{p:PyBinding BooleanToVisibility($[someToggleButton.IsChecked])}"/> 
    <CheckBox Visibility="{p:PyBinding BooleanToVisibility($[someToggleButton.IsChecked])}"/> 
</StackPanel> 

Second Attempt

<StackPanel> 
    <ToggleButton x:Name="someToggleButton" /> 
    <Button Name="myButton" Visibility="{p:PyBinding BooleanToVisibility($[someToggleButton.IsChecked])}" /> 
    <Grid Visibility="{p:PyBinding $[myButton.Visibility]}"/> 
    <TextBox Visibility="{p:PyBinding $[myButton.Visibility]}"/> 
    <CheckBox Visibility="{p:PyBinding $[myButton.Visibility]}"/> 
</StackPanel> 

Answer 3

Just looking at the original code, you could group the necessary elements into their own container and then manage the container Visibility:

<StackPanel>
    <ToggleButton x:Name="someToggleButton" />
    <StackPanel Visibility="{Binding ElementName=someToggleButton, Path=IsChecked, Converter={StaticResource BoolToVisibilityConverter}}">
        <Button />
        <Grid />
        <TextBox />
        <CheckBox />
    </StackPanel>
</StackPanel>

Actually, today I would do this with the VSM - have a state with the elements Visible and a state with them not Visible, then use two GoToState Behaviors on the Toggle button to set the state based on the button's toggle state.