DataGridViewRowPostPaintEventHandler Delegato

Definizione

Spazio dei nomi:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Rappresenta il metodo che gestirà l'evento RowPostPaint di un oggetto DataGridView.

public delegate void DataGridViewRowPostPaintEventHandler(System::Object ^ sender, DataGridViewRowPostPaintEventArgs ^ e);

public delegate void DataGridViewRowPostPaintEventHandler(object? sender, DataGridViewRowPostPaintEventArgs e);

type DataGridViewRowPostPaintEventHandler = delegate of obj * DataGridViewRowPostPaintEventArgs -> unit

Public Delegate Sub DataGridViewRowPostPaintEventHandler(sender As Object, e As DataGridViewRowPostPaintEventArgs)

Parametri

sender

Object

Origine dell'evento.

e

DataGridViewRowPostPaintEventArgs

Oggetto DataGridViewRowPostPaintEventArgs che contiene i dati dell'evento.

Esempio

Nell'esempio di codice seguente viene presentato un DataGridViewRowPostPaintEventHandler delegato che disegna il contenuto testuale che estende l'intera riga sotto i valori normali delle celle. 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 content that spans multiple columns and the focus rectangle.
void dataGridView1_RowPostPaint(object sender,
    DataGridViewRowPostPaintEventArgs e)
{
    // 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);

    SolidBrush forebrush = null;
    try
    {
        // Determine the foreground color.
        if ((e.State & DataGridViewElementStates.Selected) ==
            DataGridViewElementStates.Selected)
        {
            forebrush = new SolidBrush(e.InheritedRowStyle.SelectionForeColor);
        }
        else
        {
            forebrush = new SolidBrush(e.InheritedRowStyle.ForeColor);
        }

        // Get the content that spans multiple columns.
        object recipe =
            this.dataGridView1.Rows.SharedRow(e.RowIndex).Cells[2].Value;

        if (recipe != null)
        {
            String text = recipe.ToString();

            // Calculate the bounds for the content that spans multiple 
            // columns, adjusting for the horizontal scrolling position 
            // and the current row height, and displaying only whole
            // lines of text.
            Rectangle textArea = rowBounds;
            textArea.X -= this.dataGridView1.HorizontalScrollingOffset;
            textArea.Width += this.dataGridView1.HorizontalScrollingOffset;
            textArea.Y += rowBounds.Height - e.InheritedRowStyle.Padding.Bottom;
            textArea.Height -= rowBounds.Height -
                e.InheritedRowStyle.Padding.Bottom;
            textArea.Height = (textArea.Height / e.InheritedRowStyle.Font.Height) *
                e.InheritedRowStyle.Font.Height;

            // Calculate the portion of the text area that needs painting.
            RectangleF clip = textArea;
            clip.Width -= this.dataGridView1.RowHeadersWidth + 1 - clip.X;
            clip.X = this.dataGridView1.RowHeadersWidth + 1;
            RectangleF oldClip = e.Graphics.ClipBounds;
            e.Graphics.SetClip(clip);

            // Draw the content that spans multiple columns.
            e.Graphics.DrawString(
                text, e.InheritedRowStyle.Font, forebrush, textArea);

            e.Graphics.SetClip(oldClip);
        }
    }
    finally
    {
        forebrush.Dispose();
    }

    if (this.dataGridView1.CurrentCellAddress.Y == e.RowIndex)
    {
        // Paint the focus rectangle.
        e.DrawFocus(rowBounds, true);
    }
}

' Paints the content that spans multiple columns and the focus rectangle.
Sub dataGridView1_RowPostPaint(ByVal sender As Object, _
    ByVal e As DataGridViewRowPostPaintEventArgs) _
    Handles dataGridView1.RowPostPaint

    ' 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)

    Dim forebrush As SolidBrush = Nothing
    Try
        ' Determine the foreground color.
        If (e.State And DataGridViewElementStates.Selected) = _
            DataGridViewElementStates.Selected Then

            forebrush = New SolidBrush(e.InheritedRowStyle.SelectionForeColor)
        Else
            forebrush = New SolidBrush(e.InheritedRowStyle.ForeColor)
        End If

        ' Get the content that spans multiple columns.
        Dim recipe As Object = _
            Me.dataGridView1.Rows.SharedRow(e.RowIndex).Cells(2).Value

        If (recipe IsNot Nothing) Then
            Dim text As String = recipe.ToString()

            ' Calculate the bounds for the content that spans multiple 
            ' columns, adjusting for the horizontal scrolling position 
            ' and the current row height, and displaying only whole
            ' lines of text.
            Dim textArea As Rectangle = rowBounds
            textArea.X -= Me.dataGridView1.HorizontalScrollingOffset
            textArea.Width += Me.dataGridView1.HorizontalScrollingOffset
            textArea.Y += rowBounds.Height - e.InheritedRowStyle.Padding.Bottom
            textArea.Height -= rowBounds.Height - e.InheritedRowStyle.Padding.Bottom
            textArea.Height = (textArea.Height \ e.InheritedRowStyle.Font.Height) * _
                e.InheritedRowStyle.Font.Height

            ' Calculate the portion of the text area that needs painting.
            Dim clip As RectangleF = textArea
            clip.Width -= Me.dataGridView1.RowHeadersWidth + 1 - clip.X
            clip.X = Me.dataGridView1.RowHeadersWidth + 1
            Dim oldClip As RectangleF = e.Graphics.ClipBounds
            e.Graphics.SetClip(clip)

            ' Draw the content that spans multiple columns.
            e.Graphics.DrawString(text, e.InheritedRowStyle.Font, forebrush, _
                textArea)

            e.Graphics.SetClip(oldClip)
        End If
    Finally
        forebrush.Dispose()
    End Try

    If Me.dataGridView1.CurrentCellAddress.Y = e.RowIndex Then
        ' Paint the focus rectangle.
        e.DrawFocus(rowBounds, True)
    End If

End Sub

Commenti

Quando si crea un delegato DataGridViewRowPostPaintEventHandler, 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

Vedi anche

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