Rediger

Del via


BindingSource.Position Property

Definition

Gets or sets the index of the current item in the underlying list.

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

Property Value

A zero-based index that specifies the position of the current item in the underlying list.

Attributes

Examples

The following code example demonstrates the MoveNext, MoveFirst, Current, and Position members. To run this example, paste the code into a form that imports the System.Drawing.Drawing2D namespace and contains a BindingSource named BindingSource1 and a button named button1. Associate the Form1_Load and Form1_Paint methods with the Load and Paint events for the form, and associate the button1_click method with the Click event for button1. Visual Basic users will need to add a reference to 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

Remarks

When setting the Position property, out-of-range values are treated in the following manner:

  • Negative values are treated as 0.

  • Values greater than or equal to Count are treated as Count minus 1.

Changing the Position property will adjust the Current property likewise.

Applies to

See also