DrawListViewSubItemEventArgs.ItemState 屬性
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
取得要繪製之 ListViewItem 的父代 ListViewItem.ListViewSubItem 的目前狀態。
public:
property System::Windows::Forms::ListViewItemStates ItemState { System::Windows::Forms::ListViewItemStates get(); };public System.Windows.Forms.ListViewItemStates ItemState { get; }member this.ItemState : System.Windows.Forms.ListViewItemStatesPublic ReadOnly Property ItemState As ListViewItemStates屬性值
ListViewItemStates 值的位元組合，指出父代 ListViewItem 目前的狀態。
範例
下列程式碼範例示範如何在應用程式中使用 ItemState 屬性，以提供控制項的自訂繪圖 ListView 。 在此範例中 ListView.DrawSubItem ，事件的處理常式會繪製子專案文字值，以及具有負值的子專案的文字和背景。
如需完整的範例，請參閱 DrawListViewSubItemEventArgs 概觀參考主題。
// 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
備註
使用這個屬性來檢查要繪製的 ListViewItem.ListViewSubItem 父代是否 ListViewItem 處於特定狀態。 此屬性僅提供父專案的基本狀態資訊。 例如，您可以使用這個屬性來判斷是否已選取、核取或聚焦父專案。 如果您需要深入瞭解，請透過 Item 屬性擷取父專案，並直接檢查其屬性。
