DataGridViewRowPrePaintEventHandler Delegato

Definizione

public delegate void DataGridViewRowPrePaintEventHandler(System::Object ^ sender, DataGridViewRowPrePaintEventArgs ^ e);

public delegate void DataGridViewRowPrePaintEventHandler(object sender, DataGridViewRowPrePaintEventArgs e);

public delegate void DataGridViewRowPrePaintEventHandler(object? sender, DataGridViewRowPrePaintEventArgs e);

type DataGridViewRowPrePaintEventHandler = delegate of obj * DataGridViewRowPrePaintEventArgs -> unit

Public Delegate Sub DataGridViewRowPrePaintEventHandler(sender As Object, e As DataGridViewRowPrePaintEventArgs)

Parametri

Esempio

Nell'esempio di codice seguente viene visualizzato un delegato che disegna uno DataGridViewRowPrePaintEventHandler sfondo di riga sfumatura se la riga è selezionata. Questo esempio di codice fa parte di un esempio più grande fornito in Procedura: Personalizzare l'aspetto delle righe nel controllo DataGridView Windows Forms.

// Paints the custom selection background for selected rows.
void dataGridView1_RowPrePaint(object sender,
        DataGridViewRowPrePaintEventArgs e)
{
    // Do not automatically paint the focus rectangle.
    e.PaintParts &= ~DataGridViewPaintParts.Focus;

    // Determine whether the cell should be painted
    // with the custom selection background.
    if ((e.State & DataGridViewElementStates.Selected) ==
                DataGridViewElementStates.Selected)
    {
        // Calculate the bounds of the row.
        Rectangle rowBounds = new Rectangle(
            this.dataGridView1.RowHeadersWidth, e.RowBounds.Top,
            this.dataGridView1.Columns.GetColumnsWidth(
                DataGridViewElementStates.Visible) -
            this.dataGridView1.HorizontalScrollingOffset + 1,
            e.RowBounds.Height);

        // Paint the custom selection background.
        using (Brush backbrush =
            new System.Drawing.Drawing2D.LinearGradientBrush(rowBounds,
                this.dataGridView1.DefaultCellStyle.SelectionBackColor,
                e.InheritedRowStyle.ForeColor,
                System.Drawing.Drawing2D.LinearGradientMode.Horizontal))
        {
            e.Graphics.FillRectangle(backbrush, rowBounds);
        }
    }
}

' Paints the custom selection background for selected rows.
Sub dataGridView1_RowPrePaint(ByVal sender As Object, _
    ByVal e As DataGridViewRowPrePaintEventArgs) _
    Handles dataGridView1.RowPrePaint

    ' Do not automatically paint the focus rectangle.
    e.PaintParts = e.PaintParts And Not DataGridViewPaintParts.Focus

    ' Determine whether the cell should be painted with the 
    ' custom selection background.
    If (e.State And DataGridViewElementStates.Selected) = _
        DataGridViewElementStates.Selected Then

        ' Calculate the bounds of the row.
        Dim rowBounds As New Rectangle( _
            Me.dataGridView1.RowHeadersWidth, e.RowBounds.Top, _
            Me.dataGridView1.Columns.GetColumnsWidth( _
            DataGridViewElementStates.Visible) - _
            Me.dataGridView1.HorizontalScrollingOffset + 1, _
            e.RowBounds.Height)

        ' Paint the custom selection background.
        Dim backbrush As New _
            System.Drawing.Drawing2D.LinearGradientBrush(rowBounds, _
            Me.dataGridView1.DefaultCellStyle.SelectionBackColor, _
            e.InheritedRowStyle.ForeColor, _
            System.Drawing.Drawing2D.LinearGradientMode.Horizontal)
        Try
            e.Graphics.FillRectangle(backbrush, rowBounds)
        Finally
            backbrush.Dispose()
        End Try
    End If

End Sub

Commenti

Quando si crea un delegato DataGridViewRowPrePaintEventHandler, si identifica il metodo che gestirà l'evento. Per associare l'evento al gestore eventi in uso, aggiungere all'evento un'istanza del delegato. Il gestore eventi viene chiamato ogni volta che si verifica l'evento, a meno che non venga rimosso il delegato. Per altre informazioni sui delegati del gestore eventi, vedere Gestione e generazione di eventi.

Metodi di estensione

Si applica a

Vedi anche

• DataGridView
• RowPrePaint
• Procedura: Personalizzare l'aspetto delle righe nel controllo DataGridView di Windows Forms