BindingSource.Position Właściwość

Definicja

Przestrzeń nazw:

System.Windows.Forms

Zestaw:

System.Windows.Forms.dll

Źródło:

BindingSource.cs

Pobiera lub ustawia indeks bieżącego elementu na liście bazowej.

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

Wartość właściwości

Int32

Indeks oparty na zera, który określa pozycję bieżącego elementu na liście bazowej.

Atrybuty

BrowsableAttribute

Przykłady

Poniższy przykład kodu przedstawia MoveNextelementy członkowskie , MoveFirst, Currenti Position . Aby uruchomić ten przykład, wklej kod do formularza, który importuje System.Drawing.Drawing2D przestrzeń nazw i zawiera nazwany BindingSource i przycisk o nazwie BindingSource1button1. Form1_Load Skojarz metody i z zdarzeniami Load i PaintForm1_Paint dla formularza, a następnie skojarz button1_click metodę ze zdarzeniem Click dla button1elementu . Użytkownicy języka Visual Basic będą musieli dodać odwołanie do 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

Uwagi

Podczas ustawiania Position właściwości wartości poza zakresem są traktowane w następujący sposób:

• Wartości ujemne są traktowane jako 0.

• Wartości większe niż lub równe Count są traktowane jako Count minus 1.

Position Zmiana właściwości spowoduje dostosowanie Current właściwości podobnie.

Zobacz też

• List
• Current
• Count