Binding.ValidatesOnDataErrors 屬性

定義

命名空間:
System.Windows.Data
組件:
PresentationFramework.dll

取得或設定一個值，指示是否包含 。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 包含 DataErrorValidationRule;否則， false。

範例

以下範例使用 IDataErrorInfo 和 ValidatesOnDataErrors 來驗證使用者輸入。TextBox 第一個範例建立 IDataErrorInfo 一個資料型態，實作以報告驗證錯誤。

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

以下範例將屬性 Age 綁定於 ， TextBox 並設定 ValidatesOnDataErrors 為 true 於 Binding。 當使用者輸入無效值時，會出現紅色邊框 TextBox ，並回報 ToolTip 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

設定此屬性提供一種明確使用元素 DataErrorValidationRule 的替代方案。 這是 DataErrorValidationRule 一條內建的驗證規則，用來檢查源物件實作時 IDataErrorInfo 是否產生錯誤。 若產生錯誤，綁定引擎會產生包含錯誤的 a ValidationError ，並將其加入 Validation.Errors 綁定元素的集合中。 沒有錯誤即可消除此驗證回饋，除非其他規則提出驗證問題。

ValidatesOnDataErrors 於 .NET Framework 3.5 版本中引入。 如需詳細資訊，請參閱 .NET Framework 版本和相依性。

適用於

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