MessageBox Classe

Définition

public ref class MessageBox

public class MessageBox

type MessageBox = class

Public Class MessageBox

Héritage

Object

MessageBox

Exemples

L’exemple de code suivant montre comment utiliser un MessageBox élément pour informer l’utilisateur d’une entrée manquante dans un TextBox. Cet exemple exige que la méthode soit appelée à partir d’un formulaire existant avec un TextBox nom de serveur sur celui-ci.

private:
   void validateUserEntry()
   {
      // Checks the value of the text.
      if ( serverName->Text->Length == 0 )
      {
         // Initializes the variables to pass to the MessageBox::Show method.
         String^ message = "You did not enter a server name. Cancel this operation?";
         String^ caption = "No Server Name Specified";
         MessageBoxButtons buttons = MessageBoxButtons::YesNo;
         System::Windows::Forms::DialogResult result;

         // Displays the MessageBox.
         result = MessageBox::Show( this, message, caption, buttons );
         if ( result == ::DialogResult::Yes )
         {
            // Closes the parent form.
            this->Close();
         }
      }
   }

private void validateUserEntry()
{
    // Checks the value of the text.
    if(serverName.Text.Length == 0)
    {
        // Initializes the variables to pass to the MessageBox.Show method.
        string message = "You did not enter a server name. Cancel this operation?";
     string caption = "Error Detected in Input";
        MessageBoxButtons buttons = MessageBoxButtons.YesNo;
        DialogResult result;

        // Displays the MessageBox.
        result = MessageBox.Show(message, caption, buttons);
        if (result == System.Windows.Forms.DialogResult.Yes)
        {
            // Closes the parent form.
            this.Close();
        }
    }
}

Private Sub ValidateUserEntry()
    ' Checks the value of the text.
    If ServerName.Text.Length = 0 Then

        ' Initializes variables to pass to the MessageBox.Show method.
        Dim Message As String = "You did not enter a server name. Cancel this operation?"
        Dim Caption As String = "Error Detected in Input"
        Dim Buttons As MessageBoxButtons = MessageBoxButtons.YesNo

        Dim Result As DialogResult

        'Displays the MessageBox
        Result = MessageBox.Show(Message, Caption, Buttons)

        ' Gets the result of the MessageBox display.
        If Result = System.Windows.Forms.DialogResult.Yes Then
            ' Closes the parent form.
            Me.Close()
        End If
    End If
End Sub

L’exemple de code suivant montre comment demander à l’utilisateur une question oui ou non et prendre une décision en fonction de la réponse.

private:
   void Form1_FormClosing(Object^ sender, FormClosingEventArgs^ e)
   {
      // If the no button was pressed ...
      if ((MessageBox::Show(
         "Are you sure that you would like to close the form?", 
         "Form Closing", MessageBoxButtons::YesNo, 
         MessageBoxIcon::Question) == DialogResult::No))
      {
         // cancel the closure of the form.
         e->Cancel = true;
      }
   }

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    const string message =
        "Are you sure that you would like to close the form?";
    const string caption = "Form Closing";
    var result = MessageBox.Show(message, caption,
                                 MessageBoxButtons.YesNo,
                                 MessageBoxIcon.Question);

    // If the no button was pressed ...
    if (result == DialogResult.No)
    {
        // cancel the closure of the form.
        e.Cancel = true;
    }
}

Private Sub Form1_FormClosing( _
    ByVal sender As System.Object, _
    ByVal e As System.Windows.Forms.FormClosingEventArgs) _
    Handles MyBase.FormClosing

    Dim message As String = _
            "Are you sure that you would like to close the form?"
    Dim caption As String = "Form Closing"
    Dim result = MessageBox.Show(message, caption, _
                                 MessageBoxButtons.YesNo, _
                                 MessageBoxIcon.Question)

    ' If the no button was pressed ...
    If (result = DialogResult.No) Then
        ' cancel the closure of the form.
        e.Cancel = True
    End If
End Sub

Remarques

Vous ne pouvez pas créer une nouvelle instance de la MessageBox classe. Pour afficher une boîte de message, appelez la static méthode MessageBox.Show. Le titre, le message, les boutons et les icônes affichés dans la zone de message sont déterminés par les paramètres que vous transmettez à cette méthode.

Méthodes

S’applique à

Voir aussi

• Show(String, String, MessageBoxButtons, MessageBoxIcon, MessageBoxDefaultButton, MessageBoxOptions, Boolean)