BindingSource.Position Propriété

Définition

Espace de noms:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Source:

BindingSource.cs

Obtient ou définit l’index de l’élément actif dans la liste sous-jacente.

public:
 property int Position { int get(); void set(int value); };

[System.ComponentModel.Browsable(false)]
public int Position { get; set; }

[<System.ComponentModel.Browsable(false)>]
member this.Position : int with get, set

Public Property Position As Integer

Valeur de propriété

Int32

Index de base zéro qui spécifie la position de l’élément actif dans la liste sous-jacente.

Attributs

BrowsableAttribute

Exemples

L’exemple de code suivant illustre les membres et les MoveNextmembresMoveFirstCurrentPosition. Pour exécuter cet exemple, collez le code dans un formulaire qui importe l’espace System.Drawing.Drawing2D de noms et contient un BindingSource nom BindingSource1 et un bouton nommé button1. Associez les méthodes et les Form1_Load méthodes au Load formulaire et Paint aux événements du formulaire, puis associez la button1_click méthode à l’événement Click pour button1Form1_Paint . Les utilisateurs Visual Basic devront ajouter une référence à System.Data.dll.

    void Form1_Load(Object^ sender, EventArgs^ e)
    {
        // Set the data source to the Brush type and populate
        // bindingSource1; with some brushes.
        bindingSource1->DataSource = System::Drawing::Brush::typeid;
        bindingSource1->Add(
            gcnew TextureBrush(gcnew Bitmap(Button::typeid, "Button.bmp")));
        bindingSource1->Add(gcnew HatchBrush(HatchStyle::Cross, Color::Red));
        bindingSource1->Add(gcnew SolidBrush(Color::Blue));
    }


private:
    void moveNextButton_Click(Object^ sender, EventArgs^ e)
    {
        // If you are not at the end of the list, move to the next item
        // in the BindingSource.
        if (bindingSource1->Position + 1 < bindingSource1->Count)
        {
            bindingSource1->MoveNext();
        }
        // Otherwise, move back to the first item.
        else
        {
            bindingSource1->MoveFirst();
        }
        // Force the form to repaint.
        this->Invalidate();
    }

    void Form1_Paint(Object^ sender, PaintEventArgs^ e)
    {
        // Get the current item in the BindingSource.
        Brush^ item = (Brush^) bindingSource1->Current;

        // If the current type is a TextureBrush, fill an ellipse.
        if (item->GetType() == TextureBrush::typeid)
        {
            e->Graphics->FillEllipse(item,e->ClipRectangle);
        }
        // If the current type is a HatchBrush, fill a triangle.
        else if (item->GetType() == HatchBrush::typeid)
        {

            e->Graphics->FillPolygon(item, 
                gcnew array<Point> {*gcnew Point(0, 0),
                *gcnew Point(0, 200),
                *gcnew Point(200, 0)});
        }
        // Otherwise, fill a rectangle.
        else
        {
            e->Graphics->FillRectangle(
                (Brush^)bindingSource1->Current, e->ClipRectangle);
        }
    }

void Form1_Load(object sender, EventArgs e)
{
    // Set the data source to the Brush type and populate
    // BindingSource1 with some brushes.
    BindingSource1.DataSource = typeof(System.Drawing.Brush);
    BindingSource1.Add(
        new TextureBrush(new Bitmap(typeof(Button), "Button.bmp")));
    BindingSource1.Add(new HatchBrush(HatchStyle.Cross, Color.Red));
    BindingSource1.Add(new SolidBrush(Color.Blue));
}

private void button1_Click(object sender, EventArgs e)
{
    // If you are not at the end of the list, move to the next item
    // in the BindingSource.
    if (BindingSource1.Position + 1 < BindingSource1.Count)
        BindingSource1.MoveNext();

    // Otherwise, move back to the first item.
    else
        BindingSource1.MoveFirst();

    // Force the form to repaint.
    this.Invalidate();
}

void Form1_Paint(object sender, PaintEventArgs e)
{
    // Get the current item in the BindingSource.
    Brush item = (Brush)BindingSource1.Current;

    // If the current type is a TextureBrush, fill an ellipse.
    if (item.GetType() == typeof(TextureBrush))
        e.Graphics.FillEllipse(item,
           e.ClipRectangle);

    // If the current type is a HatchBrush, fill a triangle.
    else if (item.GetType() == typeof(HatchBrush))
        e.Graphics.FillPolygon(item,
            new Point[] { new Point(0, 0), new Point(0, 200),
            new Point(200, 0)});

    // Otherwise, fill a rectangle.
    else
        e.Graphics.FillRectangle(
            (Brush)BindingSource1.Current, e.ClipRectangle);
}

Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) _
    Handles Me.Load

    ' Set the data source to the Brush type and populate
    ' BindingSource1 with some brushes.
    BindingSource1.DataSource = GetType(System.Drawing.Brush)
    BindingSource1.Add(New TextureBrush(New Bitmap(GetType(Button), _
        "Button.bmp")))
    BindingSource1.Add(New HatchBrush(HatchStyle.Cross, Color.Red))
    BindingSource1.Add(New SolidBrush(Color.Blue))

End Sub



Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
     Handles button1.Click

    ' If you are not at the end of the list, move to the next item
    ' in the BindingSource.
    If BindingSource1.Position + 1 < BindingSource1.Count Then
        BindingSource1.MoveNext()

        ' Otherwise, move back to the first item.
    Else
        BindingSource1.MoveFirst()
    End If

    ' Force the form to repaint.
    Me.Invalidate()

End Sub


Sub Form1_Paint(ByVal sender As Object, ByVal e As PaintEventArgs)

    ' Get the current item in the BindingSource.
    Dim item As Brush = CType(BindingSource1.Current, Brush)

    ' If the current type is a TextureBrush, fill an ellipse.
    If item.GetType().Equals(GetType(TextureBrush)) Then
        e.Graphics.FillEllipse(item, _
        e.ClipRectangle)

        ' If the current type is a HatchBrush, fill a triangle.
    ElseIf item.GetType().Equals(GetType(HatchBrush)) Then
        e.Graphics.FillPolygon(item, New Point() _
         {New Point(0, 0), New Point(0, 200), New Point(200, 0)})

        ' Otherwise, fill a rectangle.
    Else
        e.Graphics.FillRectangle(item, e.ClipRectangle)
    End If

End Sub

Remarques

Lors de la définition de la Position propriété, les valeurs hors plage sont traitées de la manière suivante :

• Les valeurs négatives sont traitées comme 0.

• Les valeurs supérieures ou égales à Count sont traitées comme Count moins 1.

La modification de la Position propriété ajuste également la Current propriété.

Voir aussi

• List
• Current
• Count