ValidationStep 枚举


指定 ValidationRule 何时运行。Specifies when a ValidationRule runs.

public enum class ValidationStep
public enum ValidationStep
type ValidationStep = 
Public Enum ValidationStep


CommittedValue 3

在将值提交到源后运行 ValidationRuleRuns the ValidationRule after the value has been committed to the source.

ConvertedProposedValue 1

在转换了值后运行 ValidationRuleRuns the ValidationRule after the value is converted.

RawProposedValue 0

在进行任何转换之前运行 ValidationRuleRuns the ValidationRule before any conversion occurs.

UpdatedValue 2

在更新了源后运行 ValidationRuleRuns the ValidationRule after the source is updated.


下面的示例使用名为的验证规则 ValidateDateAndPriceThe following example uses a validation rule named ValidateDateAndPrice. ValidationRule.ValidationStep此规则的设置为, ConvertedProposedValue 以便在运行时,该 ValidationRule.Validate 方法有权访问源属性类型的值。The ValidationRule.ValidationStep for this rule is set to ConvertedProposedValue so that when it runs, the ValidationRule.Validate method has access to values that are of the source property's type.

PriceIsAPositiveNumberFutureDateRule 规则运行时,每个方法中的值 ValidationRule.Validate 都是字符串,因为的默认值 ValidationRule.ValidationStepRawProposedValueWhen the PriceIsAPositiveNumber and FutureDateRule rules run, the values in each ValidationRule.Validate method are strings because the default value of ValidationRule.ValidationStep is RawProposedValue. 因此,在将值转换为各自的类型之前,将运行规则。Therefore, the rules run before the values are converted to their respective types.

<StackPanel Name="stackPanel1"  Margin="10" Width="250"

    <Style TargetType="HeaderedContentControl">
      <Setter Property="Margin" Value="2"/>
      <Setter Property="Focusable" Value="False"/>
      <Setter Property="Template">
          <ControlTemplate TargetType="HeaderedContentControl">
            <DockPanel LastChildFill="False">
              <ContentPresenter ContentSource="Header" DockPanel.Dock="Left" Focusable="False" VerticalAlignment="Center"/>
              <ContentPresenter ContentSource="Content" Margin="5,0,0,0" DockPanel.Dock="Right" VerticalAlignment="Center"/>


    <Style TargetType="Button">
      <Setter Property="Width" Value="100"/>
      <Setter Property="Margin" Value="10,15,15,15"/>


    <BindingGroup NotifyOnValidationError="True">
        <src:ValidateDateAndPrice ValidationStep="ConvertedProposedValue" />
  <TextBlock FontSize="14" Text="Enter an item for sale"/>
  <HeaderedContentControl Header="Description">
    <TextBox Width="150" Text="{Binding Path=Description, Mode=TwoWay}"/>
  <HeaderedContentControl Header="Price">
    <TextBox Name="priceField"  Width="150">
        <Binding Path="Price" Mode="TwoWay" >
  <HeaderedContentControl Header="Date Offer Ends">
    <TextBox Name="dateField" Width="150" >
        <Binding Path="OfferExpires" StringFormat="d" >
  <StackPanel Orientation="Horizontal">
    <Button IsDefault="True" Click="Submit_Click">_Submit</Button>
    <Button IsCancel="True" Click="Cancel_Click">_Cancel</Button>
  <HeaderedContentControl Header="Description">
    <TextBlock Width="150" Text="{Binding Path=Description}"/>
  <HeaderedContentControl Header="Price">
    <TextBlock Width="150" Text="{Binding Path=Price, StringFormat=c}"/>
  <HeaderedContentControl Header="Date Offer Ends">
    <TextBlock Width="150" Text="{Binding Path=OfferExpires, StringFormat=d}"/>

下面的示例演示 ValidateDateAndPrice 验证规则。The following example shows the ValidateDateAndPrice validation rule. ValidationRule.Validate 方法中, Price 属性的类型为 Double ,属性的类型为 OfferExpires DateTimeIn the ValidationRule.Validate method, the Price property is of type Double, and the OfferExpires property is of type DateTime. 这些字符串在运行时已转换为其各自的类型 ValidationRuleThe strings have been converted to their respective types by the time the ValidationRule runs.

public class ValidateDateAndPrice : ValidationRule
    // Ensure that an item over $100 is available for at least 7 days.
    public override ValidationResult Validate(object value, CultureInfo cultureInfo)
        BindingGroup bg = value as BindingGroup;

        // Get the source object.
        PurchaseItem item = bg.Items[0] as PurchaseItem;
        object doubleValue;
        object dateTimeValue;

        // Get the proposed values for Price and OfferExpires.
        bool priceResult = bg.TryGetValue(item, "Price", out doubleValue);
        bool dateResult = bg.TryGetValue(item, "OfferExpires", out dateTimeValue);

        if (!priceResult || !dateResult)
            return new ValidationResult(false, "Properties not found");

        double price = (double)doubleValue;
        DateTime offerExpires = (DateTime)dateTimeValue;

        // Check that an item over $100 is available for at least 7 days.
        if (price > 100)
            if (offerExpires < DateTime.Today + new TimeSpan(7, 0, 0, 0))
                return new ValidationResult(false, "Items over $100 must be available for at least 7 days.");

        return ValidationResult.ValidResult;
Public Class ValidateDateAndPrice
    Inherits ValidationRule
    ' Ensure that an item over $100 is available for at least 7 days.
    Public Overrides Function Validate(ByVal value As Object, ByVal cultureInfo As CultureInfo) As ValidationResult
        Dim bg As BindingGroup = TryCast(value, BindingGroup)

        ' Get the source object.
        Dim item As PurchaseItem = TryCast(bg.Items(0), PurchaseItem)

        Dim doubleValue As Object = Nothing
        Dim dateTimeValue As Object = Nothing

        ' Get the proposed values for Price and OfferExpires.
        Dim priceResult As Boolean = bg.TryGetValue(item, "Price", doubleValue)
        Dim dateResult As Boolean = bg.TryGetValue(item, "OfferExpires", dateTimeValue)

        If (Not priceResult) OrElse (Not dateResult) Then
            Return New ValidationResult(False, "Properties not found")
        End If

        Dim price As Double = CDbl(doubleValue)
        Dim offerExpires As Date = CDate(dateTimeValue)

        ' Check that an item over $100 is available for at least 7 days.
        If price > 100 Then
            If offerExpires < Date.Today + New TimeSpan(7, 0, 0, 0) Then
                Return New ValidationResult(False, "Items over $100 must be available for at least 7 days.")
            End If
        End If

        Return ValidationResult.ValidResult

    End Function
End Class