ComboBox.Text ComboBox.Text ComboBox.Text ComboBox.Text Property

Definizione

Ottiene o imposta il testo associato a questo controllo.Gets or sets the text associated with this control.

public:
 virtual property System::String ^ Text { System::String ^ get(); void set(System::String ^ value); };
[System.ComponentModel.Bindable(true)]
public override string Text { get; set; }
member this.Text : string with get, set
Public Overrides Property Text As String

Valore della proprietà

Testo associato a questo controllo.The text associated with this control.

Esempi

Nell'esempio di codice riportato di seguito viene illustrato ComboBox come inizializzare un Text controllo impostando la AddRange proprietà e utilizzando ComboBoxil metodo per popolare.The following code example demonstrates how to initialize a ComboBox control by setting the Text property and using the AddRange method to populate the ComboBox. Viene inoltre illustrato come gestire DropDown l'evento.It also demonstrates handling the DropDown event. Per eseguire l'esempio, incollare il codice seguente in un form e chiamare il InitializeComboBox metodo nel costruttore o Load nell'evento del modulo.To run the example, paste the following code in a form and call the InitializeComboBox method in the form's constructor or Load event.

internal:
   // Declare ComboBox1
   System::Windows::Forms::ComboBox^ ComboBox1;

private:
   // Initialize ComboBox1.
   void InitializeComboBox()
   {
      this->ComboBox1 = gcnew ComboBox;
      this->ComboBox1->Location = System::Drawing::Point( 128, 48 );
      this->ComboBox1->Name = "ComboBox1";
      this->ComboBox1->Size = System::Drawing::Size( 100, 21 );
      this->ComboBox1->TabIndex = 0;
      this->ComboBox1->Text = "Typical";
      array<String^>^ installs = {"Typical","Compact","Custom"};
      ComboBox1->Items->AddRange( installs );
      this->Controls->Add( this->ComboBox1 );
      
      // Hook up the event handler.
      this->ComboBox1->DropDown += gcnew System::EventHandler(
         this, &Form1::ComboBox1_DropDown );
   }

   // Handles the ComboBox1 DropDown event. If the user expands the  
   // drop-down box, a message box will appear, recommending the
   // typical installation.
   void ComboBox1_DropDown( Object^ sender, System::EventArgs^ e )
   {
      MessageBox::Show( "Typical installation is strongly recommended.",
         "Install information", MessageBoxButtons::OK,
         MessageBoxIcon::Information );
   }

// Declare ComboBox1.
internal System.Windows.Forms.ComboBox ComboBox1;

// Initialize ComboBox1.
private void InitializeComboBox()
{
    this.ComboBox1 = new ComboBox();
    this.ComboBox1.Location = new System.Drawing.Point(128, 48);
    this.ComboBox1.Name = "ComboBox1";
    this.ComboBox1.Size = new System.Drawing.Size(100, 21);
    this.ComboBox1.TabIndex = 0;
    this.ComboBox1.Text	= "Typical";
    string[] installs = new string[]{"Typical", "Compact", "Custom"};
    ComboBox1.Items.AddRange(installs);
    this.Controls.Add(this.ComboBox1);
    
    // Hook up the event handler.
    this.ComboBox1.DropDown +=  
        new System.EventHandler(ComboBox1_DropDown);
}

// Handles the ComboBox1 DropDown event. If the user expands the  
// drop-down box, a message box will appear, recommending the
// typical installation.
private void ComboBox1_DropDown(object sender, System.EventArgs e)
{
    MessageBox.Show("Typical installation is strongly recommended.", 
    "Install information", MessageBoxButtons.OK, 
        MessageBoxIcon.Information);
}

' Declare ComboBox1.
Friend WithEvents ComboBox1 As System.Windows.Forms.ComboBox

' Initialize ComboBox1.
Private Sub InitializeComboBox()
    Me.ComboBox1 = New ComboBox
    Me.ComboBox1.Location = New System.Drawing.Point(128, 48)
    Me.ComboBox1.Name = "ComboBox1"
    Me.ComboBox1.Size = New System.Drawing.Size(100, 21)
    Me.ComboBox1.TabIndex = 0
    Me.ComboBox1.Text = "Typical"
    Dim installs() As String = New String() _
        {"Typical", "Compact", "Custom"}
    ComboBox1.Items.AddRange(installs)
    Me.Controls.Add(Me.ComboBox1)
End Sub

' Handles the ComboBox1 DropDown event. If the user expands the  
' drop-down box, a message box will appear, recommending the
' typical installation.
Private Sub ComboBox1_DropDown _ 
    (ByVal sender As Object, ByVal e As System.EventArgs) _ 
    Handles ComboBox1.DropDown
    MessageBox.Show("Typical installation is strongly recommended.", _
    "Install information", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub

Commenti

Se si Text imposta la null proprietà su o su una stringa vuota ("" SelectedIndex ), l'oggetto viene impostato su-1.Setting the Text property to null or an empty string ("") sets the SelectedIndex to -1. Impostando Text la proprietà su un valore presente Items nella raccolta, l'oggetto SelectedIndex viene impostato sull'indice di tale elemento.Setting the Text property to a value that is in the Items collection sets the SelectedIndex to the index of that item. Se si Text imposta la proprietà su un valore che non è presente nella raccolta SelectedIndex , l'oggetto rimarrà invariato.Setting the Text property to a value that is not in the collection leaves the SelectedIndex unchanged.

Si applica a