fx:Evaluate markup extension, $x

The fx:Evaluate markup extension evaluates its source path once. It can be used in value-supplier and property-consumer position:

Value supplier: evaluates the source path once and supplies the resulting value to the enclosing construct.
Property consumer: evaluates the source path once and assigns the resulting value to the target property.

A leading .. in the source path selects the content of the source collection. In that form, fx:Evaluate assigns the collection content to the target collection.

Its prefix notation is $x, where x is the source path.

Properties

Property	Description
`path`	A string that specifies the source path. This is the default property.

Usage

<!-- Element notation -->
<object>
    <property>
        <fx:Evaluate path="myPath"/>
    </property>
</object>

<!-- Attribute notation -->
<object property="{fx:Evaluate path=myPath}"/>

<!-- Attribute notation with omitted "path" -->
<object property="{fx:Evaluate myPath}"/>

<!-- Prefix notation -->
<object property="$myPath"/>

Usage as a value supplier

When fx:Evaluate is nested inside another markup extension, it supplies the value of the evaluated expression to the enclosing construct:

<Label text="{StaticResource message; formatArguments=$amount}"/>

In this example, $amount evaluates the amount path once and passes the resulting value to the formatArguments parameter of StaticResource.

Usage as a property consumer

When fx:Evaluate is applied directly to a property, it assigns the evaluated value once and does not keep the property synchronized afterward.

<Label text="$title"/>