TextBoxBase.SelectionLength TextBoxBase.SelectionLength TextBoxBase.SelectionLength TextBoxBase.SelectionLength Property

Définition

Obtient ou définit le nombre de caractères sélectionnés dans la zone de texte.Gets or sets the number of characters selected in the text box.

public:
 virtual property int SelectionLength { int get(); void set(int value); };
[System.ComponentModel.Browsable(false)]
public virtual int SelectionLength { get; set; }
member this.SelectionLength : int with get, set
Public Overridable Property SelectionLength As Integer

Valeur de propriété

Nombre de caractères sélectionnés dans la zone de texte.The number of characters selected in the text box.

Exceptions

La valeur assignée est inférieure à zéro.The assigned value is less than zero.

Exemples

L’exemple de code suivant TextBoxutilise, une classe dérivée.The following code example uses TextBox, a derived class. Il fournit Click des gestionnaires d’événements MenuItem pour les objets qui effectuent des opérations couper, copier, coller et annuler.It provides Click event handlers for MenuItem objects that perform Cut, Copy, Paste, and Undo operations. Cet exemple nécessite qu’un TextBox contrôle nommé textBox1 ait été créé.This example requires that a TextBox control named textBox1 has been created.

private:
   void Menu_Copy( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      // Ensure that text is selected in the text box.   
      if ( textBox1->SelectionLength > 0 )
      {
         // Copy the selected text to the Clipboard.
         textBox1->Copy();
      }
   }

   void Menu_Cut( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      // Ensure that text is currently selected in the text box.   
      if (  !textBox1->SelectedText->Equals( "" ) )
      {
         // Cut the selected text in the control and paste it into the Clipboard.
         textBox1->Cut();
      }
   }

   void Menu_Paste( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      // Determine if there is any text in the Clipboard to paste into the text box.
      if ( Clipboard::GetDataObject()->GetDataPresent( DataFormats::Text ) == true )
      {
         // Determine if any text is selected in the text box.
         if ( textBox1->SelectionLength > 0 )
         {
            // Ask user if they want to paste over currently selected text.
            if ( MessageBox::Show( "Do you want to paste over current selection?",
               "Cut Example", MessageBoxButtons::YesNo ) == ::DialogResult::No )
            {
               // Move selection to the point after the current selection and paste.
               textBox1->SelectionStart = textBox1->SelectionStart + textBox1->SelectionLength;
            }
         }
         // Paste current text in Clipboard into text box.
         textBox1->Paste();
      }
   }

   void Menu_Undo( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      // Determine if last operation can be undone in text box.   
      if ( textBox1->CanUndo == true )
      {
         // Undo the last operation.
         textBox1->Undo();
         // Clear the undo buffer to prevent last action from being redone.
         textBox1->ClearUndo();
      }
   }
private void Menu_Copy(System.Object sender, System.EventArgs e)
 {
    // Ensure that text is selected in the text box.   
    if(textBox1.SelectionLength > 0)
        // Copy the selected text to the Clipboard.
        textBox1.Copy();
 }
 
 private void Menu_Cut(System.Object sender, System.EventArgs e)
 {   
     // Ensure that text is currently selected in the text box.   
     if(textBox1.SelectedText != "")
        // Cut the selected text in the control and paste it into the Clipboard.
        textBox1.Cut();
 }
 
 private void Menu_Paste(System.Object sender, System.EventArgs e)
 {
    // Determine if there is any text in the Clipboard to paste into the text box.
    if(Clipboard.GetDataObject().GetDataPresent(DataFormats.Text) == true)
    {
        // Determine if any text is selected in the text box.
        if(textBox1.SelectionLength > 0)
        {
          // Ask user if they want to paste over currently selected text.
          if(MessageBox.Show("Do you want to paste over current selection?", "Cut Example", MessageBoxButtons.YesNo) == DialogResult.No)
             // Move selection to the point after the current selection and paste.
             textBox1.SelectionStart = textBox1.SelectionStart + textBox1.SelectionLength;
        }
        // Paste current text in Clipboard into text box.
        textBox1.Paste();
    }
 }
 
 
 private void Menu_Undo(System.Object sender, System.EventArgs e)
 {
    // Determine if last operation can be undone in text box.   
    if(textBox1.CanUndo == true)
    {
       // Undo the last operation.
       textBox1.Undo();
       // Clear the undo buffer to prevent last action from being redone.
       textBox1.ClearUndo();
    }
 }
 
Private Sub Menu_Copy(sender As System.Object, e As System.EventArgs)
    ' Ensure that text is selected in the text box.   
    If textBox1.SelectionLength > 0 Then
        ' Copy the selected text to the Clipboard.
        textBox1.Copy()
    End If
End Sub
 
Private Sub Menu_Cut(sender As System.Object, e As System.EventArgs)
    ' Ensure that text is currently selected in the text box.   
    If textBox1.SelectedText <> "" Then
        ' Cut the selected text in the control and paste it into the Clipboard.
        textBox1.Cut()
    End If
End Sub
 
Private Sub Menu_Paste(sender As System.Object, e As System.EventArgs)
    ' Determine if there is any text in the Clipboard to paste into the text box.
    If Clipboard.GetDataObject().GetDataPresent(DataFormats.Text) = True Then
        ' Determine if any text is selected in the text box.
        If textBox1.SelectionLength > 0 Then
            ' Ask user if they want to paste over currently selected text.
            If MessageBox.Show("Do you want to paste over current selection?", _
                "Cut Example", MessageBoxButtons.YesNo) = DialogResult.No Then
                ' Move selection to the point after the current selection and paste.
                textBox1.SelectionStart = textBox1.SelectionStart + _
                    textBox1.SelectionLength
            End If
        End If 
        ' Paste current text in Clipboard into text box.
        textBox1.Paste()
    End If
End Sub

Private Sub Menu_Undo(sender As System.Object, e As System.EventArgs)
    ' Determine if last operation can be undone in text box.   
    If textBox1.CanUndo = True Then
        ' Undo the last operation.
        textBox1.Undo()
        ' Clear the undo buffer to prevent last action from being redone.
        textBox1.ClearUndo()
    End If
End Sub

Remarques

Vous pouvez utiliser cette propriété pour déterminer si des caractères sont actuellement sélectionnés dans le contrôle zone de texte avant d’effectuer des opérations sur le texte sélectionné.You can use this property to determine if any characters are currently selected in the text box control before performing operations on the selected text. Lorsque la valeur de la SelectionLength propriété est supérieure au nombre de caractères dans le texte du contrôle, la valeur de la SelectionLength propriété est définie sur la longueur totale du texte dans le contrôle moins la valeur de l’entité SelectionStartpropriété (si une valeur est spécifiée pour la SelectionStart propriété).When the value of the SelectionLength property is set to a value that is larger than the number of characters within the text of the control, the value of the SelectionLength property is set to the entire length of text within the control minus the value of the SelectionStart property (if any value is specified for the SelectionStart property).

Notes

Vous pouvez déplacer par programmation le signe insertion dans la zone de texte en affectant SelectionStart à la position dans la zone de texte où vous souhaitez déplacer le point d’insertion et affecter à SelectionLength la propriété une valeur de zéro (0).You can programmatically move the caret within the text box by setting the SelectionStart to the position within the text box where you want the caret to move to and set the SelectionLength property to a value of zero (0). La zone de texte doit avoir le focus pour que le signe insertion puisse être déplacé.The text box must have focus in order for the caret to be moved.

S’applique à

Voir aussi