TreeNodeStates 列舉
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。
定義常數，表示 TreeNode的可能狀態。
此列舉支援其成員值的位元組合。
public enum class TreeNodeStates[System.Flags]
public enum TreeNodeStates[<System.Flags>]
type TreeNodeStates = Public Enum TreeNodeStates- 繼承
- 屬性
欄位
| 名稱 | 值 | Description |
|---|---|---|
| Selected | 1 | 節點被選中。 |
| Grayed | 2 | 該節點已被停用。 |
| Checked | 8 | 節點被檢查。 |
| Focused | 16 | 節點有焦點。 |
| Default | 32 | 節點處於預設狀態。 |
| Hot | 64 | 節點是熱的。 當屬性 HotTracking 設定為 且 |
| Marked | 128 | 節點已被標記。 |
| Indeterminate | 256 | 節點處於不確定狀態。 |
| ShowKeyboardCues | 512 | 節點應該會顯示鍵盤快捷鍵。 |
範例
以下範例示範如何利用擁有者繪圖來自訂 TreeView 控制。 TreeView範例中的控制項會顯示可選的節點標籤，與一般節點標籤並列。 節點標籤是利用 屬性 TreeNode.Tag 來指定的。 這個 TreeView 控制器也使用自訂顏色，包括自訂的高亮色。
你可以透過設定顏色屬性來自訂大部分 TreeView 顏色，但選取高亮色作為屬性並不可使用。 此外，預設的選取矩形只延伸到節點標籤周圍。 必須使用擁有者繪圖來繪製節點標籤，並繪製一個足夠大的自訂高亮矩形以包含節點標籤。
在範例中，事件 TreeView.DrawNode 的處理器透過呼叫類別中 DrawTreeNodeEventArgs 的方法來抽取未被選取的節點。 這些方法為不需要自訂的元素提供預設外觀 TreeView 。 處理器手動繪製節點標籤與自訂選取高亮。
完整範例請參見 TreeView.DrawNode 參考主題。
// Draws a node.
private:
void myTreeView_DrawNode( Object^ sender, DrawTreeNodeEventArgs^ e )
{
// Draw the background and node text for a selected node.
if ( (e->State & TreeNodeStates::Selected) != (TreeNodeStates)0 )
{
// Draw the background of the selected node. The NodeBounds
// method makes the highlight rectangle large enough to
// include the text of a node tag, if one is present.
e->Graphics->FillRectangle( Brushes::Green, NodeBounds( e->Node ) );
// Retrieve the node font. If the node font has not been set,
// use the TreeView font.
System::Drawing::Font^ nodeFont = e->Node->NodeFont;
if ( nodeFont == nullptr )
nodeFont = (dynamic_cast<TreeView^>(sender))->Font;
// Draw the node text.
e->Graphics->DrawString( e->Node->Text, nodeFont, Brushes::White, Rectangle::Inflate( e->Bounds, 2, 0 ) );
}
// Use the default background and node text.
else
{
e->DrawDefault = true;
}
// If a node tag is present, draw its string representation
// to the right of the label text.
if ( e->Node->Tag != nullptr )
{
e->Graphics->DrawString( e->Node->Tag->ToString(), tagFont, Brushes::Yellow, (float)e->Bounds.Right + 2, (float)e->Bounds.Top );
}
// If the node has focus, draw the focus rectangle large, making
// it large enough to include the text of the node tag, if present.
if ( (e->State & TreeNodeStates::Focused) != (TreeNodeStates)0 )
{
Pen^ focusPen = gcnew Pen( Color::Black );
try
{
focusPen->DashStyle = System::Drawing::Drawing2D::DashStyle::Dot;
Rectangle focusBounds = NodeBounds( e->Node );
focusBounds.Size = System::Drawing::Size( focusBounds.Width - 1, focusBounds.Height - 1 );
e->Graphics->DrawRectangle( focusPen, focusBounds );
}
finally
{
if ( focusPen )
delete safe_cast<IDisposable^>(focusPen);
}
}
}
// Draws a node.
private void myTreeView_DrawNode(
object sender, DrawTreeNodeEventArgs e)
{
// Draw the background and node text for a selected node.
if ((e.State & TreeNodeStates.Selected) != 0)
{
// Draw the background of the selected node. The NodeBounds
// method makes the highlight rectangle large enough to
// include the text of a node tag, if one is present.
e.Graphics.FillRectangle(Brushes.Green, NodeBounds(e.Node));
// Retrieve the node font. If the node font has not been set,
// use the TreeView font.
Font nodeFont = e.Node.NodeFont;
if (nodeFont == null) nodeFont = ((TreeView)sender).Font;
// Draw the node text.
e.Graphics.DrawString(e.Node.Text, nodeFont, Brushes.White,
Rectangle.Inflate(e.Bounds, 2, 0));
}
// Use the default background and node text.
else
{
e.DrawDefault = true;
}
// If a node tag is present, draw its string representation
// to the right of the label text.
if (e.Node.Tag != null)
{
e.Graphics.DrawString(e.Node.Tag.ToString(), tagFont,
Brushes.Yellow, e.Bounds.Right + 2, e.Bounds.Top);
}
// If the node has focus, draw the focus rectangle large, making
// it large enough to include the text of the node tag, if present.
if ((e.State & TreeNodeStates.Focused) != 0)
{
using (Pen focusPen = new Pen(Color.Black))
{
focusPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
Rectangle focusBounds = NodeBounds(e.Node);
focusBounds.Size = new Size(focusBounds.Width - 1,
focusBounds.Height - 1);
e.Graphics.DrawRectangle(focusPen, focusBounds);
}
}
}
' Draws a node.
Private Sub myTreeView_DrawNode(ByVal sender As Object, _
ByVal e As DrawTreeNodeEventArgs) Handles myTreeView.DrawNode
' Draw the background and node text for a selected node.
If (e.State And TreeNodeStates.Selected) <> 0 Then
' Draw the background of the selected node. The NodeBounds
' method makes the highlight rectangle large enough to
' include the text of a node tag, if one is present.
e.Graphics.FillRectangle(Brushes.Green, NodeBounds(e.Node))
' Retrieve the node font. If the node font has not been set,
' use the TreeView font.
Dim nodeFont As Font = e.Node.NodeFont
If nodeFont Is Nothing Then
nodeFont = CType(sender, TreeView).Font
End If
' Draw the node text.
e.Graphics.DrawString(e.Node.Text, nodeFont, Brushes.White, _
e.Bounds.Left - 2, e.Bounds.Top)
' Use the default background and node text.
Else
e.DrawDefault = True
End If
' If a node tag is present, draw its string representation
' to the right of the label text.
If (e.Node.Tag IsNot Nothing) Then
e.Graphics.DrawString(e.Node.Tag.ToString(), tagFont, _
Brushes.Yellow, e.Bounds.Right + 2, e.Bounds.Top)
End If
' If the node has focus, draw the focus rectangle large, making
' it large enough to include the text of the node tag, if present.
If (e.State And TreeNodeStates.Focused) <> 0 Then
Dim focusPen As New Pen(Color.Black)
Try
focusPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot
Dim focusBounds As Rectangle = NodeBounds(e.Node)
focusBounds.Size = New Size(focusBounds.Width - 1, _
focusBounds.Height - 1)
e.Graphics.DrawRectangle(focusPen, focusBounds)
Finally
focusPen.Dispose()
End Try
End If
End Sub
備註
此枚舉方式被 State 類別的性質 DrawTreeNodeEventArgs 所使用。 欲了解更多資訊，請參閱該活動。TreeView.DrawNode
