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Binding.ValidatesOnDataErrors 屬性

定義

取得或設定值,這個值表示是否要包含 DataErrorValidationRule

public:
 property bool ValidatesOnDataErrors { bool get(); void set(bool value); };
public bool ValidatesOnDataErrors { get; set; }
member this.ValidatesOnDataErrors : bool with get, set
Public Property ValidatesOnDataErrors As Boolean

屬性值

Boolean

true 表示包含 DataErrorValidationRule,否則為 false

範例

下列範例會使用 IDataErrorInfoValidatesOnDataErrors 來驗證 中的 TextBox 使用者輸入。 第一個範例會建立實 IDataErrorInfo 作以報告驗證錯誤的資料類型。

public class PersonImplementsIDataErrorInfo : IDataErrorInfo
{
    private int age;

    public int Age
    {
        get { return age; }
        set { age = value; }
    }

    public string Error
    {
        get
        {
            return "";
        }
    }

    public string this[string name]
    {
        get
        {
            string result = null;

            if (name == "Age")
            {
                if (this.age < 0 || this.age > 150)
                {
                    result = "Age must not be less than 0 or greater than 150.";
                }
            }
            return result;
        }
    }
}
Public Class PersonImplementsIDataErrorInfo
    Implements System.ComponentModel.IDataErrorInfo
    Private m_age As Integer

    Public Property Age() As Integer
        Get
            Return m_age
        End Get
        Set(ByVal value As Integer)
            m_age = value
        End Set
    End Property

    Public ReadOnly Property [Error]() As String _
                    Implements System.ComponentModel.IDataErrorInfo.Error
        Get
            Return ""
        End Get
    End Property

    Default Public ReadOnly Property Item(ByVal name As String) As String _
                            Implements System.ComponentModel.IDataErrorInfo.Item
        Get
            Dim result As String = Nothing

            If name = "Age" Then
                If Me.m_age < 0 OrElse Me.m_age > 150 Then
                    result = "Age must not be less than 0 or greater than 150."
                End If
            End If
            Return result
        End Get
    End Property
End Class

下列範例會將 Age 屬性系結至 , TextBox 並將 設定 ValidatesOnDataErrorstrueBinding 當使用者輸入不正確值時,紅色框線會出現在 中 TextBox ,並 ToolTip 報告錯誤訊息。

<StackPanel Margin="20">
  <StackPanel.Resources>
    <src:PersonImplementsIDataErrorInfo x:Key="data"/>
    
    <!--The tool tip for the TextBox to display the validation error message.-->
    <Style x:Key="textBoxInError" TargetType="TextBox">
      <Style.Triggers>
        <Trigger Property="Validation.HasError" Value="true">
          <Setter Property="ToolTip"
              Value="{Binding RelativeSource={x:Static RelativeSource.Self},
              Path=(Validation.Errors)[0].ErrorContent}"/>
        </Trigger>
      </Style.Triggers>
    </Style>

  </StackPanel.Resources>
  <TextBlock>Enter your age:</TextBlock>
  <TextBox Style="{StaticResource textBoxInError}">
    <TextBox.Text>
      <!--ValidatesOnDataErrors to is set to True, so the Binding
          checks for errors raised by the IDataErrorInfo object.
          An alternative syntax is to add <DataErrorValidationRule/> within
          the <Binding.ValidationRules> section.-->
      <Binding Path="Age" Source="{StaticResource data}"
               ValidatesOnDataErrors="True"
               UpdateSourceTrigger="PropertyChanged">
      </Binding>
    </TextBox.Text>
  </TextBox>
  <TextBlock>Mouse-over to see the validation error message.</TextBlock>
</StackPanel>

備註

設定這個屬性可提供明確使用 元素的 DataErrorValidationRule 替代方案。 DataErrorValidationRule是內建的驗證規則,會檢查來源物件的實作所 IDataErrorInfo 引發的錯誤。 如果引發錯誤,系結引擎會 ValidationError 建立 ,並產生錯誤,並將它新增至 Validation.Errors 繫結項目目的集合。 除非另一個規則引發驗證問題,否則缺少錯誤會清除此驗證意見反應。

ValidatesOnDataErrors.NET Framework 3.5 版引進。 如需詳細資訊,請參閱 .NET Framework 版本和相依性

適用於

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