DrawListViewSubItemEventArgs.Graphics Propriedade

Definição

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Origem:

DrawListViewSubItemEventArgs.cs

Obtém o Graphics usado para desenhar o ListViewItem.ListViewSubItem.

public:
 property System::Drawing::Graphics ^ Graphics { System::Drawing::Graphics ^ get(); };

public System.Drawing.Graphics Graphics { get; }

member this.Graphics : System.Drawing.Graphics

Public ReadOnly Property Graphics As Graphics

Valor da propriedade

Graphics

Um Graphics usado para desenhar o ListViewItem.ListViewSubItem.

Exemplos

O exemplo de código a seguir demonstra como usar a Graphics propriedade em um aplicativo que fornece desenho personalizado para um ListView controle. No exemplo, um manipulador para o ListView.DrawSubItem evento desenha os valores de texto do subitem e o texto e a tela de fundo para subitens que têm valores negativos.

Para obter o exemplo completo, consulte o DrawListViewSubItemEventArgs tópico de referência de visão geral.

// Draws subitem text and applies content-based formatting.
private void listView1_DrawSubItem(object sender,
    DrawListViewSubItemEventArgs e)
{
    TextFormatFlags flags = TextFormatFlags.Left;

    using (StringFormat sf = new StringFormat())
    {
        // Store the column text alignment, letting it default
        // to Left if it has not been set to Center or Right.
        switch (e.Header.TextAlign)
        {
            case HorizontalAlignment.Center:
                sf.Alignment = StringAlignment.Center;
                flags = TextFormatFlags.HorizontalCenter;
                break;
            case HorizontalAlignment.Right:
                sf.Alignment = StringAlignment.Far;
                flags = TextFormatFlags.Right;
                break;
        }

        // Draw the text and background for a subitem with a 
        // negative value. 
        double subItemValue;
        if (e.ColumnIndex > 0 && Double.TryParse(
            e.SubItem.Text, NumberStyles.Currency,
            NumberFormatInfo.CurrentInfo, out subItemValue) &&
            subItemValue < 0)
        {
            // Unless the item is selected, draw the standard 
            // background to make it stand out from the gradient.
            if ((e.ItemState & ListViewItemStates.Selected) == 0)
            {
                e.DrawBackground();
            }

            // Draw the subitem text in red to highlight it. 
            e.Graphics.DrawString(e.SubItem.Text,
                listView1.Font, Brushes.Red, e.Bounds, sf);

            return;
        }

        // Draw normal text for a subitem with a nonnegative 
        // or nonnumerical value.
        e.DrawText(flags);
    }
}

' Draws subitem text and applies content-based formatting.
Private Sub listView1_DrawSubItem(ByVal sender As Object, _
    ByVal e As DrawListViewSubItemEventArgs) _
    Handles listView1.DrawSubItem

    Dim flags As TextFormatFlags = TextFormatFlags.Left

    Dim sf As New StringFormat()
    Try

        ' Store the column text alignment, letting it default
        ' to Left if it has not been set to Center or Right.
        Select Case e.Header.TextAlign
            Case HorizontalAlignment.Center
                sf.Alignment = StringAlignment.Center
                flags = TextFormatFlags.HorizontalCenter
            Case HorizontalAlignment.Right
                sf.Alignment = StringAlignment.Far
                flags = TextFormatFlags.Right
        End Select

        ' Draw the text and background for a subitem with a 
        ' negative value. 
        Dim subItemValue As Double
        If e.ColumnIndex > 0 AndAlso _
            Double.TryParse(e.SubItem.Text, NumberStyles.Currency, _
            NumberFormatInfo.CurrentInfo, subItemValue) AndAlso _
            subItemValue < 0 Then

            ' Unless the item is selected, draw the standard 
            ' background to make it stand out from the gradient.
            If (e.ItemState And ListViewItemStates.Selected) = 0 Then
                e.DrawBackground()
            End If

            ' Draw the subitem text in red to highlight it. 
            e.Graphics.DrawString(e.SubItem.Text, _
                Me.listView1.Font, Brushes.Red, e.Bounds, sf)

            Return

        End If

        ' Draw normal text for a subitem with a nonnegative 
        ' or nonnumerical value.
        e.DrawText(flags)

    Finally
        sf.Dispose()
    End Try

End Sub

Comentários

A Graphics classe fornece propriedades e métodos úteis para desenhar no dispositivo de exibição.

Confira também

• Graphics
• ListView
• DrawSubItem
• ListViewItem.ListViewSubItem