DrawListViewSubItemEventArgs.SubItem 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

获取要绘制的 ListViewItem.ListViewSubItem。

public:
 property System::Windows::Forms::ListViewItem::ListViewSubItem ^ SubItem { System::Windows::Forms::ListViewItem::ListViewSubItem ^ get(); };

public System.Windows.Forms.ListViewItem.ListViewSubItem? SubItem { get; }

member this.SubItem : System.Windows.Forms.ListViewItem.ListViewSubItem

Public ReadOnly Property SubItem As ListViewItem.ListViewSubItem

属性值

ListViewItem.ListViewSubItem

要绘制的 ListViewItem.ListViewSubItem。

示例

下面的代码示例演示如何在为控件提供自定义绘图ListView的应用程序中使用 SubItem 属性。 在此示例中，事件的处理程序 ListView.DrawSubItem 绘制子项文本值，以及具有负值的子项的文本和背景。

有关完整示例，请参阅 DrawListViewSubItemEventArgs 概述参考主题。

// 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

注解

当其他 DrawListViewSubItemEventArgs 属性未提供足够的信息来满足你的需求时，此方法非常有用。 属性 SubItem 允许访问所绘制 的所有 ListViewItem.ListViewSubItem 成员。 例如，必须直接访问此对象，以自行绘制 ListViewItem.ListViewSubItem.Text 值，而不是使用 DrawText 方法。

另请参阅

• ListView
• DrawSubItem
• OwnerDraw
• ListViewItem.ListViewSubItem
• Item