Control.CausesValidation Control.CausesValidation Control.CausesValidation Control.CausesValidation Property

Definition

Ruft einen Wert ab, der angibt, ob das Steuerelement bei Erhalt des Fokus eine Validierung für alle eine Validierung erfordernden Steuerelemente veranlasst, oder legt diesen fest.Gets or sets a value indicating whether the control causes validation to be performed on any controls that require validation when it receives focus.

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

Eigenschaftswert

true, wenn das Steuerelement eine Validierung für alle eine Validierung erfordernden Steuerelemente veranlasst, wenn es den Fokus erhält, andernfalls false.true if the control causes validation to be performed on any controls requiring validation when it receives focus; otherwise, false. Die Standardeinstellung ist true.The default is true.

Beispiele

Im folgenden Codebeispiel wird die abgeleitete TextBox Klasse verwendet und eine e-Mail-Adresse überprüft, die der Benutzer eingibt.The following code example uses the derived class TextBox and validates an email address that the user enters. Wenn die e-Mail-Adresse nicht im Standardformat vorliegt (@" and ""."), schlägt die Validierung fehl ErrorProvider , ein Symbol wird angezeigt, und das Ereignis wird abgebrochen.If the email address is not in the standard format (containing "@" and "."), the validation fails, an ErrorProvider icon is displayed, and the event is canceled. CausesValidation Fürfalseeine der Schaltflächen im Formular ist die-Eigenschaft auf festgelegt.One of the buttons on the form has its CausesValidation property set to false. Durch Klicken oder Festlegen des Fokus auf diese Schaltfläche wird keine Validierung auslöst.Clicking or setting focus to this button does not trigger validation. Für dieses Beispiel TextBox ErrorProvider ist es erforderlich, dass, ein- Button Steuerelement und ein-Element in einem Formular erstellt wurden.This example requires that a TextBox, an ErrorProvider control, and a Button have been created on a form.

public:
   Form1()
   {
      InitializeComponent();    
      //Set button2 to be non-validating.
      this->button2->CausesValidation = false;
   }

private:
   void textBox1_Validating( Object^ sender, System::ComponentModel::CancelEventArgs^ e )
   {
      String^ errorMsg;
      if ( !ValidEmailAddress( textBox1->Text, &errorMsg ) )
      {
         // Cancel the event and select the text to be corrected by the user.
         e->Cancel = true;
         textBox1->Select( 0, textBox1->Text->Length );
         
         // Set the ErrorProvider error with the text to display.
         this->errorProvider1->SetError( textBox1, errorMsg );
      }
   }

   void textBox1_Validated( Object^ sender, System::EventArgs^ e )
   {
      // If all conditions have been met, clear the ErrorProvider of errors.
      errorProvider1->SetError( textBox1, "" );
   }

public:
   bool ValidEmailAddress( String^ emailAddress, [Out]interior_ptr<String^> errorMessage )
   {
      // Confirm that the email address String* is not empty.
      if ( emailAddress->Length == 0 )
      {
         *errorMessage = "email address is required.";
         return false;
      }

      // Confirm that there is an "@" and a "." in the email address, and in the correct order.
      if ( emailAddress->IndexOf( "@" ) > -1 )
      {
         if ( emailAddress->IndexOf( ".", emailAddress->IndexOf( "@" ) ) > emailAddress->IndexOf( "@" ) )
         {
            *errorMessage = "";
            return true;
         }
      }

      *errorMessage = "email address must be valid email address format.\n" +
         "For example 'someone@example.com' ";
      return false;
   }
public Form1()
{
    InitializeComponent();
    //Set button2 to be non-validating.
    this.button2.CausesValidation = false;
}


private void textBox1_Validating(object sender, 
 				System.ComponentModel.CancelEventArgs e)
{
   string errorMsg;
   if(!ValidEmailAddress(textBox1.Text, out errorMsg))
   {
      // Cancel the event and select the text to be corrected by the user.
      e.Cancel = true;
      textBox1.Select(0, textBox1.Text.Length);

      // Set the ErrorProvider error with the text to display. 
      this.errorProvider1.SetError(textBox1, errorMsg);
   }
}

private void textBox1_Validated(object sender, System.EventArgs e)
{
   // If all conditions have been met, clear the ErrorProvider of errors.
   errorProvider1.SetError(textBox1, "");
}
public bool ValidEmailAddress(string emailAddress, out string errorMessage)
{
   // Confirm that the email address string is not empty.
   if(emailAddress.Length == 0)
   {
      errorMessage = "email address is required.";
         return false;
   }

   // Confirm that there is an "@" and a "." in the email address, and in the correct order.
   if(emailAddress.IndexOf("@") > -1)
   {
      if(emailAddress.IndexOf(".", emailAddress.IndexOf("@") ) > emailAddress.IndexOf("@") )
      {
         errorMessage = "";
         return true;
      }
   }
   
   errorMessage = "email address must be valid email address format.\n" +
      "For example 'someone@example.com' ";
      return false;
}
    Public Sub New()
        MyBase.New()

        InitializeComponent()
        'Set button2 to be non-validating.
        Me.button2.CausesValidation = False
    End Sub

   Private Function ValidEmailAddress(ByVal emailAddress As String, ByRef errorMessage As String) As Boolean
      ' Confirm there is text in the control.
      If textBox1.Text.Length = 0 Then
         errorMessage = "Email address is required."
         Return False

      End If

      ' Confirm that there is an "@" and a "." in the email address, and in the correct order.
      If emailAddress.IndexOf("@") > -1 Then
         If (emailAddress.IndexOf(".", emailAddress.IndexOf("@")) > emailAddress.IndexOf("@")) Then
            errorMessage = ""
            Return True
         End If
      End If

      errorMessage = "Email address must be valid email address format." + ControlChars.Cr + _
        "For example 'someone@example.com' "
      Return False
End Function

   Private Sub textBox1_Validating(ByVal sender As Object, _
   ByVal e As System.ComponentModel.CancelEventArgs) Handles textBox1.Validating

      Dim errorMsg As String
      If Not ValidEmailAddress(textBox1.Text, errorMsg) Then
         ' Cancel the event and select the text to be corrected by the user.
         e.Cancel = True
         textBox1.Select(0, textBox1.Text.Length)

         ' Set the ErrorProvider error with the text to display. 
         Me.errorProvider1.SetError(textBox1, errorMsg)
      End If
   End Sub


   Private Sub textBox1_Validated(ByVal sender As Object, _
   ByVal e As System.EventArgs) Handles textBox1.Validated
      ' If all conditions have been met, clear the error provider of errors.
      errorProvider1.SetError(textBox1, "")
   End Sub

Hinweise

Wenn die CausesValidation -Eigenschaft auf falsefestgelegt ist Validating , Validated werden die Ereignisse und unterdrückt.If the CausesValidation property is set to false, the Validating and Validated events are suppressed.

Der CausesValidation -Eigenschafts Wert wird in false der Regel für Steuerelemente wie z. b. eine Hilfe SchaltflächeThe CausesValidation property value is typically set to false for controls such as a Help button.

Gilt für:

Siehe auch