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POMy first C# WPF ValidationRule is not firing
 

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  1. POMy first C# WPF ValidationRule is not firing
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    <p>I am trying learn how to implement data validation but my first attempt is not firing the lblSource_Error event; does anyone know what I have missed?</p> <p>My Window's XAML:</p> <pre><code>&lt;Window x:Class="cCompleteWPFResourcesExamples.wValidationRule" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:cCompleteWPFResourcesExamples" Title="wValidationRule" Height="300" Width="300"&gt; &lt;Window.Resources&gt; &lt;local:Customer x:Key="rCustomer" Forename="InXaml" Surname="Created" ID="1" AmountOutstanding="0"/&gt; &lt;/Window.Resources&gt; &lt;StackPanel x:Name="stkMain" DataContext="{StaticResource rCustomer}"&gt; &lt;Label x:Name="lblSource" Validation.Error="lblSource_Error"&gt; &lt;Label.Content&gt; &lt;Binding Path="ID" NotifyOnValidationError="True"&gt; &lt;Binding.ValidationRules&gt; &lt;local:cIDValidationRule/&gt; &lt;/Binding.ValidationRules&gt; &lt;/Binding&gt; &lt;/Label.Content&gt; &lt;/Label&gt; &lt;Label x:Name="lblErrorMessage" Content="No Error Yet"/&gt; &lt;/StackPanel&gt; &lt;/Window&gt; </code></pre> <p>My Window's code:</p> <pre><code> namespace cCompleteWPFResourcesExamples { /// &lt;summary&gt; /// Interaction logic for wValidationRule.xaml /// &lt;/summary&gt; public partial class wValidationRule : Window { Customer cus = new Customer(); public wValidationRule() { InitializeComponent(); cus.ID = 0; stkMain.DataContext = cus; } private void lblSource_Error(object sender, ValidationErrorEventArgs e) { lblErrorMessage.Content = e.Error.ErrorContent.ToString(); } } } </code></pre> <p>My ValidationRule:</p> <pre><code>using System.Windows.Controls; namespace cCompleteWPFResourcesExamples { public class cIDValidationRule : ValidationRule { public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo) { int iValue = (int)value; if (iValue == 0) return new ValidationResult(false, "No ID number"); return new ValidationResult(true, null); } } } </code></pre> <p>The Customer object is very simple: Just a few properties.</p> <p>Thanks!</p> <p>James</p>
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    1. USjames pearce
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    1. COLabel? Labels aren't inputs, so I wouldn't think validation would work for them...
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    2. COThe id field of your custom object can be edited on the form or is just showed? The validation rule will be checked when you modify the value
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      1. USSalvatore Sorbello
 

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