ValidationStep 列舉
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
指定 ValidationRule 何時執行。
public enum class ValidationStep
public enum ValidationStep
type ValidationStep =
Public Enum ValidationStep
- 繼承
欄位
| 名稱 | 值 | Description |
|---|---|---|
| RawProposedValue | 0 | 在任何轉換發生前執行。ValidationRule |
| ConvertedProposedValue | 1 | 在轉換值後執行。ValidationRule |
| UpdatedValue | 2 | 在原始碼更新後才執行。ValidationRule |
| CommittedValue | 3 | 在將值提交到原始碼後執行。ValidationRule |
範例
以下範例使用名為 ValidateDateAndPrice的驗證規則。
ValidationRule.ValidationStep此規則的 for 設定為 ,ConvertedProposedValue使得執行時方法ValidationRule.Validate能存取來源屬性的值。
當 和 PriceIsAPositiveNumberFutureDateRule 規則執行時,每個 ValidationRule.Validate 方法的值都是字串,因為 的 ValidationRule.ValidationStep 預設值是 RawProposedValue。 因此,規則會在數值轉換成各自類型之前執行。
<StackPanel Name="stackPanel1" Margin="10" Width="250"
Loaded="stackPanel1_Loaded"
Validation.Error="ItemError">
<StackPanel.Resources>
<Style TargetType="HeaderedContentControl">
<Setter Property="Margin" Value="2"/>
<Setter Property="Focusable" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<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"/>
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="Button">
<Setter Property="Width" Value="100"/>
<Setter Property="Margin" Value="10,15,15,15"/>
</Style>
</StackPanel.Resources>
<StackPanel.BindingGroup>
<BindingGroup NotifyOnValidationError="True">
<BindingGroup.ValidationRules>
<src:ValidateDateAndPrice ValidationStep="ConvertedProposedValue" />
</BindingGroup.ValidationRules>
</BindingGroup>
</StackPanel.BindingGroup>
<TextBlock FontSize="14" Text="Enter an item for sale"/>
<HeaderedContentControl Header="Description">
<TextBox Width="150" Text="{Binding Path=Description, Mode=TwoWay}"/>
</HeaderedContentControl>
<HeaderedContentControl Header="Price">
<TextBox Name="priceField" Width="150">
<TextBox.Text>
<Binding Path="Price" Mode="TwoWay" >
<Binding.ValidationRules>
<src:PriceIsAPositiveNumber/>
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
</HeaderedContentControl>
<HeaderedContentControl Header="Date Offer Ends">
<TextBox Name="dateField" Width="150" >
<TextBox.Text>
<Binding Path="OfferExpires" StringFormat="d" >
<Binding.ValidationRules>
<src:FutureDateRule/>
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
</HeaderedContentControl>
<StackPanel Orientation="Horizontal">
<Button IsDefault="True" Click="Submit_Click">_Submit</Button>
<Button IsCancel="True" Click="Cancel_Click">_Cancel</Button>
</StackPanel>
<HeaderedContentControl Header="Description">
<TextBlock Width="150" Text="{Binding Path=Description}"/>
</HeaderedContentControl>
<HeaderedContentControl Header="Price">
<TextBlock Width="150" Text="{Binding Path=Price, StringFormat=c}"/>
</HeaderedContentControl>
<HeaderedContentControl Header="Date Offer Ends">
<TextBlock Width="150" Text="{Binding Path=OfferExpires, StringFormat=d}"/>
</HeaderedContentControl>
</StackPanel>
以下範例展示了 ValidateDateAndPrice 驗證規則。 在該 ValidationRule.Validate 方法中,屬性 Price 為型態 Double,而屬性 OfferExpires 為型別 DateTime。 在 ValidationRule 運行時,弦已經轉換成各自的類型。
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