CODEWITHSUNDEEP
c#xaml
Patrick
Patrick

Reputation: 779

How do you reference one XAML object value from another?

XAML is a capable of building trees of C# objects, just as you would in code; however, although I can instantiate objects no problem, I am stuck with the syntax for initialising one to the value of another (if this is even possible).

To illustrate, consider the following pointless example:

<Application xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MyClass">

    <x:String x:Name="MyString">Hello</x:String>

    <x:String x:Name="MyString2">STUCK FOR SYNTAX HERE</x:String>

The strings are instantiated. I can see them in the debugger and I can write code to manipulate them just as if they were normal pieces of C# code. My question is: can I use the value of the first string 'Hello' to initialise the second string? Or, put more generally, can I access the value of one XAML object from another XAML object?

Hope this makes sense.

Upvotes: 0

Views: 384

Answers (1)

Kcvin
Kcvin

Reputation: 5163

Your code snippet does not compile. The answer to your question is no, and going out on a limb here, but you're likely misusing XAML. As Dennis said in the comment, you should be using data-binding. The closest thing that matches what you're trying to do is this:

<Window ....
        xmlns:sys="clr-namespace:System;assembly=mscorlib" >
    <Window.Resources>
        <system:String x:Key="MyString">Hello</system:String>
        <system:String x:Key="MyString2">STUCK FOR SYNTAX HERE</system:String>
    </Window.Resources>
    <TextBlock>
        <TextBlock.Text>
            <MultiBinding StringFormat="{}{0} - {1}">
                <Binding Source="{StaticResource MyString}" />
                <Binding Source="{StaticResource MyString2}" />
            </MultiBinding>
        </TextBlock.Text>
    </TextBlock>
</Window>

The following code would show "Hello - STUCK FOR SYNTAX HERE" in a text block.

The reason you can't concat strings in XAML is because you're literally initializing a System.String which does not support any kind of other type markup.

Upvotes: 2

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