BindingExpressionBase.ValidateWithoutUpdate 메서드

정의

네임스페이스:

System.Windows.Data

어셈블리:

PresentationFramework.dll

속성이 설정되었거나 ConvertedProposedValue으로 설정된 연결된 Binding 개체에서 ValidationStep 모든 ValidationRule 개체를 RawProposedValue 실행합니다. 이 메서드는 원본을 업데이트하지 않습니다.

public:
 bool ValidateWithoutUpdate();

public bool ValidateWithoutUpdate();

member this.ValidateWithoutUpdate : unit -> bool

Public Function ValidateWithoutUpdate () As Boolean

반환

Boolean

유효성 검사 규칙이 성공하면

예제

다음 예제에서는 설명 섹션에서 설명하는 시나리오를 보여 줍니다. 이 예제에서는 사용자가 라이브러리 항목에 대한 데이터를 입력하고 데이터를 제출할 수 있도록 합니다. 명명 callNum 된 바인딩에 TextBoxValidationRule 연결된 바인딩이 있습니다. 포커스가 TextBox 끊어지면 예제에서는 .를 호출합니다 ValidateWithoutUpdate. 사용자가 제출 단추를 클릭하면 변경 내용을 커밋하는 예제가 호출 UpdateSource 됩니다. 다음 XAML은 애플리케이션에 대한 사용자 인터페이스를 만듭니다.

<StackPanel>
    <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>

</StackPanel.Resources>
    <HeaderedContentControl Header="Title">
        <TextBox Width="150" Text="{Binding Path=Title, Mode=TwoWay}"/>
    </HeaderedContentControl>
    <HeaderedContentControl Header="Due Date">
        <TextBox Width="150" Text="{Binding Path=DueDate, StringFormat=d, Mode=TwoWay}">

        </TextBox>
    </HeaderedContentControl>
    
    <HeaderedContentControl Header="Call Number">
        <TextBox Name="CallNum" Width="150"
                 LostFocus="CallNum_LostFocus"
                 Validation.Error="CallNum_Error">
            <TextBox.Text>
                <Binding xmlns:src="clr-namespace:BindingExpressionBaseValidateWithoutUpdating"
                    Path="CallNumber" Mode="TwoWay"
                    NotifyOnValidationError="True"
                    UpdateSourceTrigger="Explicit">
                    <Binding.ValidationRules>
                        <src:CallNumberRule ValidationStep="ConvertedProposedValue"/>
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
        </TextBox>
    </HeaderedContentControl>

    <Button Click="Button_Click">Submit</Button>
    
    <HeaderedContentControl Header="Title">
        <TextBlock Text="{Binding Path=Title, Mode=TwoWay}"/>
    </HeaderedContentControl>
    
    <HeaderedContentControl Header="Due Date">
        <TextBlock Text="{Binding Path=DueDate, StringFormat=d, Mode=TwoWay}"/>
    </HeaderedContentControl>
    
    <HeaderedContentControl Header="Call Number">
        <TextBlock Text="{Binding CallNumber}"/>
    </HeaderedContentControl>

</StackPanel>

다음 예제에서는 사용자 인터페이스에 대한 논리를 보여줍니다.

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;

namespace BindingExpressionBaseValidateWithoutUpdating
{

    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            // Create an object and set it to the window's DataContext.
            LibraryItem item = new LibraryItem("Enter the title",
                    "Enter the call number",  DateTime.Now + new TimeSpan(14, 0, 0, 0));

            this.DataContext = item;
        }

        // Check whether the call number is valid when the
        // TextBox loses foces.
        private void CallNum_LostFocus(object sender, RoutedEventArgs e)
        {
            BindingExpression be = CallNum.GetBindingExpression(TextBox.TextProperty);

            be.ValidateWithoutUpdate();
        }

        // Show the validation error when one occurs.
        private void CallNum_Error(object sender, ValidationErrorEventArgs e)
        {
            if (e.Action == ValidationErrorEventAction.Added)
            {
                MessageBox.Show(e.Error.ErrorContent.ToString());
            }
        }

        // Update the source data object when the user clicks
        // the submit button.
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            BindingExpression be = CallNum.GetBindingExpression(TextBox.TextProperty);

            be.UpdateSource();
        }
    }
}

Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data


Partial Public Class Window1
    Inherits Window
    Public Sub New()
        InitializeComponent()

        ' Create an object and set it to the window's DataContext.
        Dim item As New LibraryItem("Enter the title", "Enter the call number", DateTime.Now + New TimeSpan(14, 0, 0, 0))

        Me.DataContext = item
    End Sub

    ' Check whether the call number is valid when the
    ' TextBox loses foces.
    Private Sub CallNum_LostFocus(ByVal sender As Object, ByVal e As RoutedEventArgs)
        Dim be As BindingExpression = CallNum.GetBindingExpression(TextBox.TextProperty)

        be.ValidateWithoutUpdate()
    End Sub


    ' Show the validation error when one occurs.
    Private Sub CallNum_Error(ByVal sender As Object, ByVal e As ValidationErrorEventArgs)
        If e.Action = ValidationErrorEventAction.Added Then
            MessageBox.Show(e.[Error].ErrorContent.ToString())

        End If
    End Sub

    ' Update the source data object when the user clicks
    ' the submit button.
    Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
        Dim be As BindingExpression = CallNum.GetBindingExpression(TextBox.TextProperty)

        be.UpdateSource()
    End Sub
End Class

다음 예제에서는 데이터 개체 및 ValidationRule 애플리케이션에 대 한 합니다.

using System;
using System.ComponentModel;
using System.Windows.Controls;
using System.Globalization;

namespace BindingExpressionBaseValidateWithoutUpdating
{
    // LibraryItem implements INotifyPropertyChanged so that the 
    // application is notified when a property changes.  It 
    // implements IEditableObject so that pending changes can be discarded.
    // In this example, the application does not discard changes.
    public class LibraryItem : INotifyPropertyChanged, IEditableObject
    {
        struct ItemData
        {
            internal string Title;
            internal string CallNumber;
            internal DateTime DueDate;
        }

        ItemData copyData;
        ItemData currentData;

        public LibraryItem(string title, string callNum, DateTime dueDate)
        {
            Title = title;
            CallNumber = callNum;
            DueDate = dueDate;
        }

        public string Title
        {
            get { return currentData.Title; }
            set
            {
                if (currentData.Title != value)
                {
                    currentData.Title = value;
                    NotifyPropertyChanged("Title");
                }
            }
        }

        public string CallNumber
        {
            get { return currentData.CallNumber; }
            set
            {
                if (currentData.CallNumber != value)
                {
                    currentData.CallNumber = value;
                    NotifyPropertyChanged("CallNumber");
                }
            }
        }

        public DateTime DueDate
        {
            get { return currentData.DueDate; }
            set
            {
                if (value != currentData.DueDate)
                {
                    currentData.DueDate = value;
                    NotifyPropertyChanged("DueDate");
                }
            }
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        protected void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }

        #endregion

        #region IEditableObject Members

        public virtual void BeginEdit()
        {
            copyData = currentData;
        }

        public virtual void CancelEdit()
        {
            currentData = copyData;
            NotifyPropertyChanged("");
        }

        public virtual void EndEdit()
        {
            copyData = new ItemData();
        }

        #endregion

    }

    public class CallNumberRule : ValidationRule
    {
        // A valid call number contains a period (.)
        // and 6 characters after the period.
        public override ValidationResult Validate(object value, 
                                         CultureInfo cultureInfo)
        {
            string callNum = (string)value;

            int dotIndex = callNum.IndexOf(".");
            if (dotIndex == -1 || dotIndex == 0)
            {
                return new ValidationResult(false, 
                    "There must be characters followed by a period (.) in the call number.");
            }

            string substr = callNum.Substring(dotIndex + 1);

            if (substr.Length != 6)
            {
                return new ValidationResult(false, 
                    "The call number must have 6 characters after the period (.).");
            }

            return ValidationResult.ValidResult;
        }
    }
}

Imports System.ComponentModel
Imports System.Windows.Controls
Imports System.Globalization

' LibraryItem implements INotifyPropertyChanged so that the 
' application is notified when a property changes. It 
' implements IEditableObject so that pending changes can be discarded.
' In this example, the application does not discard changes.
Public Class LibraryItem
    Implements INotifyPropertyChanged
    Implements IEditableObject
    Private Structure ItemData
        Friend Title As String
        Friend CallNumber As String
        Friend DueDate As DateTime
    End Structure

    Private copyData As ItemData
    Private currentData As ItemData

    Public Sub New(ByVal title As String, ByVal callNum As String, ByVal dueDate As DateTime)
        Me.Title = title
        Me.CallNumber = callNum
        Me.DueDate = DueDate
    End Sub

    Public Property Title() As String
        Get
            Return currentData.Title
        End Get
        Set(ByVal value As String)
            If currentData.Title <> value Then
                currentData.Title = value
                NotifyPropertyChanged("Title")
            End If
        End Set
    End Property

    Public Property CallNumber() As String
        Get
            Return currentData.CallNumber
        End Get
        Set(ByVal value As String)
            If currentData.CallNumber <> value Then
                currentData.CallNumber = value
                NotifyPropertyChanged("CallNumber")
            End If
        End Set
    End Property

    Public Property DueDate() As DateTime
        Get
            Return currentData.DueDate
        End Get
        Set(ByVal value As DateTime)
            If value <> currentData.DueDate Then
                currentData.DueDate = value
                NotifyPropertyChanged("DueDate")
            End If
        End Set
    End Property

#Region "INotifyPropertyChanged Members"

    Public Event PropertyChanged As PropertyChangedEventHandler _
        Implements INotifyPropertyChanged.PropertyChanged

    Protected Sub NotifyPropertyChanged(ByVal info As [String])
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info))
    End Sub

#End Region

#Region "IEditableObject Members"

    Public Overridable Sub BeginEdit() _
        Implements IEditableObject.BeginEdit

        copyData = currentData
    End Sub

    Public Overridable Sub CancelEdit() _
        Implements IEditableObject.CancelEdit

        currentData = copyData

        NotifyPropertyChanged("")
    End Sub

    Public Overridable Sub EndEdit() _
        Implements IEditableObject.EndEdit

        copyData = New ItemData()
    End Sub

#End Region

End Class

Public Class CallNumberRule
    Inherits ValidationRule

    ' A valid call number contains a period (.)
    ' and 6 characters after the period.
    Public Overloads Overrides Function Validate(ByVal value As Object,
                               ByVal cultureInfo As CultureInfo) As ValidationResult

        Dim callNum As String = DirectCast(value, String)

        Dim dotIndex As Integer = callNum.IndexOf(".")

        If dotIndex = -1 OrElse dotIndex = 0 Then
            Return New ValidationResult(False,
                "There must be characters followed by a period (.) in the call number.")
        End If

        Dim substr As String = callNum.Substring(dotIndex + 1)

        If substr.Length <> 6 Then
            Return New ValidationResult(False,
                "The call number must have 6 characters after the period (.).")
        End If

        Return ValidationResult.ValidResult
    End Function
End Class

설명

이 ValidateWithoutUpdate 메서드를 사용하면 바인딩의 원본을 업데이트하지 않고 바인딩에서 유효성 검사 규칙을 실행할 수 있습니다. 이는 애플리케이션에서 사용자 입력의 유효성을 검사하고 원본을 다른 시간에 업데이트하려는 경우에 유용합니다.

예를 들어 제출 단추가 포함된 데이터 원본을 업데이트하는 양식이 있다고 가정해 보겠습니다. 사용자가 양식을 제출하기 전에 잘못된 값을 입력한 경우 사용자에게 피드백을 제공하려고 합니다. 바인딩의 속성을 설정하여 포커스가 손실될 때 호출 ValidateWithoutUpdate 하여 Explicit 필드의 UpdateSourceTrigger 유효성을 TextBox 확인할 수 있습니다.