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I want set Tag property with int value in xaml. But defining int in resources and then reference this resource as binding looks not a perfect way for me. It is easier just to convert string value to int from code. So, is there some way to easy set int value in xaml?

arteny
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4 Answers4

21

Please try this.

Add namespace xmlns:sys="clr-namespace:System;assembly=mscorlib" in xaml 

<sys:Int16 x:Key="IntNo">1</sys:Int16> or

<sys:Int32 x:Key="IntNo1" >1</sys:Int32>

Note : Similarly You can use for Double value also.

Heena
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13

If not interested in declaring it as resource, you can declare it in-line somewhat like this:

    <Button>
        <Button.Tag>
            <sys:Int32>5</sys:Int32>
        </Button.Tag>
    </Button>
Rohit Vats
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    Unfortunately it is too many letters too. I need set Tag for several elements like `Tag="int:0", Tag="int:1"` and so on – arteny Jan 04 '14 at 14:54
  • `Tag` property is of type `object`. Even when you want to access it from code behind, you have to do typecast `(int)button.Tag`. Can you tell the use case? – Rohit Vats Jan 04 '14 at 14:57
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    yes, but (int)button.Tag is more simple than int.Parse((string)button.Tag) :) ok, as I understand to use string values for this looks is simplest existing way – arteny Jan 04 '14 at 15:15
  • Yeah there is no other way in XAML. Or using Resource also seems good to me. – Rohit Vats Jan 04 '14 at 15:22
  • @Arteny - For either approach, you can make a static extension method that gets the tag property and casts it to int. E.g. `public static int TagAsInt(this YourBaseElementClass e) { return (int)e.Tag; }`. Then usage is trivial `myElement.TagAsInt()`. If it is easier to define Tag as a string, you just change that method to do the parse, and use it exactly the same. – ToolmakerSteve Jun 18 '18 at 19:40
  • That's more like "in-four-lines" – Pawcio Dec 15 '21 at 09:19
10
xmlns:sys="clr-namespace:System;assembly=mscorlib"


<Grid>
    <Grid.Resources>
        <sys:Int32 x:Key="IntValue" >1</sys:Int32>
    </Grid.Resources>
    <Button x:Name="Button" Tag="{StaticResource IntValue}"></Button>
</Grid>

Is it simple enough? The above sample will be suitable if you going to use your Value in several places. Otherwise: 

<Button x:Name="Button" >
        <Button.Tag>
            <sys:Int32>1</sys:Int32>
        </Button.Tag>
    </Button>
Code Ars
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2

In XAML 2009 you can simply use the "x" prefix, like x:Boolean, x:Decimal or x:Int32.

See Microsoft - Built-in types for common XAML language primitives


Example:

This example is from a WinUI 3 application (WinUI 3 XAML is very similar to UWP XAML and mostly similar to WPF XAML)

<Window
    x:Class="MyApp.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="MyApp"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">
    <Grid>
        <Button x:Name="MyButton" Click="MyButton_Click" Content="Print 'Tag' value to console">
           <Button.Tag>
              <x:Int32>42</x:Int32>
           </Button.Tag>
         </Button>    
    </Grid>
</Window>

Code behind:

    private void MyButton_Click(object sender, RoutedEventArgs e)
    {
        int value = (int) MyButton.Tag;

        Debug.WriteLine(value);
    }

You can also spefify a command parameter that accepts an int in that way:

<Button Command="{x:Bind ViewModel.AddMinutesCommand}" Content="+ 30 Minutes">
   <Button.CommandParameter>
      <x:Int32>30</x:Int32>
   </Button.CommandParameter>
</Button>

There seems to be a confusion about the availability of XAML 2009 in various technologies: Stackoverflow - Can XAML 2009-related markup extensions be used in WPF?

Honestly, I also do not understand why my working example code can just use xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml for the x namespace instead of having to specify something like 2009/xaml here.

Feel free to change this answer, if you can clarify this.

Martin
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