TreeView.AfterLabelEdit イベントとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

TreeView.AfterLabelEdit イベント

ツリーノードのラベルテキストが編集された後に発生します。

名前空間: System.Windows.Forms
アセンブリ: System.Windows.Forms (system.windows.forms.dll 内)
構文

Visual Basic (宣言)

Public Event AfterLabelEdit As
 NodeLabelEditEventHandler

Visual Basic (使用法)

Dim instance As TreeView
Dim handler As NodeLabelEditEventHandler

AddHandler instance.AfterLabelEdit, handler

public event NodeLabelEditEventHandler AfterLabelEdit

C++

public:
event NodeLabelEditEventHandler^ AfterLabelEdit {
    void add (NodeLabelEditEventHandler^ value);
    void remove (NodeLabelEditEventHandler^ value);
}

/** @event */
public void add_AfterLabelEdit (NodeLabelEditEventHandler
 value)

/** @event */
public void remove_AfterLabelEdit (NodeLabelEditEventHandler
 value)

JScript

JScript では、イベントは使用できますが、新規に宣言することはできません。

解説

イベント処理の詳細については、「イベントの利用」を参照してください。

使用例

ContextMenu を使用して、ユーザーがルート以外のツリーノードを編集できるようにするコード例を次に示します。ユーザーがマウスを右クリックすると、ポインタ位置にある TreeNode が判断され、mySelectedNode という名前の変数に格納されます。ルート以外のツリーノードが選択された場合、そのツリーノードはユーザーが編集できる状態になります。ユーザーがツリーノードのラベル編集を停止すると、新しいラベルテキストが評価され、保存されます。この例では、いくつかの文字がラベルテキストとして無効であると判断されます。ラベル文字列に無効な文字が 1 文字でも含まれている場合、または文字列が空の場合は、ユーザーにエラーが通知され、ラベルテキストは前の状態に戻されます。

Visual Basic

' Get the tree node under the mouse pointer and
' save it in the mySelectedNode variable. 
Private Sub treeView1_MouseDown(sender As
 Object, _
  e As System.Windows.Forms.MouseEventArgs)
        
   mySelectedNode = treeView1.GetNodeAt(e.X, e.Y)
End Sub    
    
Private Sub menuItem1_Click(sender As
 Object, e As System.EventArgs)
   If Not (mySelectedNode Is
 Nothing) And _
     Not (mySelectedNode.Parent Is Nothing)
 Then
      treeView1.SelectedNode = mySelectedNode
      treeView1.LabelEdit = True
      If Not mySelectedNode.IsEditing Then
         mySelectedNode.BeginEdit()
      End If
   Else
      MessageBox.Show("No tree node selected or selected node
 is a root node." & _
        Microsoft.VisualBasic.ControlChars.Cr & _
        "Editing of root nodes is not allowed.", "Invalid
 selection")
   End If
End Sub    
    
Private Sub treeView1_AfterLabelEdit(sender
 As Object, _
  e As System.Windows.Forms.NodeLabelEditEventArgs)
   If Not (e.Label Is Nothing)
 Then
      If e.Label.Length > 0 Then
         If e.Label.IndexOfAny(New Char()
 {"@"c, "."c, ","c,
 "!"c}) = -1 Then
            ' Stop editing without canceling the label change.
            e.Node.EndEdit(False)
         Else
            ' Cancel the label edit action, inform the user, and
            ' place the node in edit mode again. 
            e.CancelEdit = True
            MessageBox.Show("Invalid tree node label."
 & _
              Microsoft.VisualBasic.ControlChars.Cr & _
              "The invalid characters are: '@','.', ',', '!'",
 _
              "Node Label Edit")
            e.Node.BeginEdit()
         End If
      Else
         ' Cancel the label edit action, inform the user, and
         ' place the node in edit mode again. 
         e.CancelEdit = True
         MessageBox.Show("Invalid tree node label."
 & _
           Microsoft.VisualBasic.ControlChars.Cr & _
           "The label cannot be blank", "Node
 Label Edit")
           e.Node.BeginEdit()
      End If
         Me.treeView1.LabelEdit = False
   End If
End Sub

/* Get the tree node under the mouse pointer and 
   save it in the mySelectedNode variable. */
private void treeView1_MouseDown(object sender,
 
  System.Windows.Forms.MouseEventArgs e)
{
   mySelectedNode = treeView1.GetNodeAt(e.X, e.Y);
}

private void menuItem1_Click(object sender,
 System.EventArgs e)
{
   if (mySelectedNode != null && mySelectedNode.Parent
 != null)
   {
      treeView1.SelectedNode = mySelectedNode;
      treeView1.LabelEdit = true;
      if(!mySelectedNode.IsEditing)
      {
         mySelectedNode.BeginEdit();
      }
   }
   else
   {
      MessageBox.Show("No tree node selected or selected node is a root node.\n"
 + 
         "Editing of root nodes is not allowed.", "Invalid selection");
   }
}

private void treeView1_AfterLabelEdit(object
 sender, 
         System.Windows.Forms.NodeLabelEditEventArgs e)
{
   if (e.Label != null)
   {
     if(e.Label.Length > 0)
     {
        if (e.Label.IndexOfAny(new char[]{'@',
 '.', ',', '!'}) == -1)
        {
           // Stop editing without canceling the label change.
           e.Node.EndEdit(false);
        }
        else
        {
           /* Cancel the label edit action, inform the user, and 
              place the node in edit mode again. */
           e.CancelEdit = true;
           MessageBox.Show("Invalid tree node label.\n" + 
              "The invalid characters are: '@','.', ',', '!'", 
              "Node Label Edit");
           e.Node.BeginEdit();
        }
     }
     else
     {
        /* Cancel the label edit action, inform the user, and 
           place the node in edit mode again. */
        e.CancelEdit = true;
        MessageBox.Show("Invalid tree node label.\nThe label cannot be blank",
 
           "Node Label Edit");
        e.Node.BeginEdit();
     }
     this.treeView1.LabelEdit = false;
   }
}

C++

   /* Get the tree node under the mouse pointer and 
      save it in the mySelectedNode variable. */
private:
   void treeView1_MouseDown( Object^ /*sender*/, System::Windows::Forms::MouseEventArgs^
 e )
   {
      mySelectedNode = treeView1->GetNodeAt( e->X, e->Y );
   }

   void menuItem1_Click( Object^ /*sender*/, System::EventArgs^
 /*e*/ )
   {
      if ( mySelectedNode != nullptr && mySelectedNode->Parent
 != nullptr )
      {
         treeView1->SelectedNode = mySelectedNode;
         treeView1->LabelEdit = true;
         if (  !mySelectedNode->IsEditing )
         {
            mySelectedNode->BeginEdit();
         }
      }
      else
      {
         MessageBox::Show( String::Concat( "No tree node selected or selected
 node is a root node.\n",
            "Editing of root nodes is not allowed." ), "Invalid selection"
 );
      }
   }

   void treeView1_AfterLabelEdit( Object^ /*sender*/,
      System::Windows::Forms::NodeLabelEditEventArgs^ e )
   {
      if ( e->Label != nullptr )
      {
         if ( e->Label->Length > 0 )
         {
            array<Char>^ temp0 = {'@','.',',','!'};
            if ( e->Label->IndexOfAny( temp0 ) == -1 )
            {
               
               // Stop editing without canceling the label change.
               e->Node->EndEdit( false );
            }
            else
            {
               /* Cancel the label edit action, inform the user, and 
                  place the node in edit mode again. */
               e->CancelEdit = true;
               MessageBox::Show( String::Concat( "Invalid tree node label.\n"
,
                  "The invalid characters are: '@','.', ',', '!'" ),
                  "Node Label Edit" );
               e->Node->BeginEdit();
            }
         }
         else
         {
            /* Cancel the label edit action, inform the user, and 
               place the node in edit mode again. */
            e->CancelEdit = true;
            MessageBox::Show( "Invalid tree node label.\nThe label cannot be
 blank",
               "Node Label Edit" );
            e->Node->BeginEdit();
         }
         this->treeView1->LabelEdit = false;
      }
   }

/* Get the tree node under the mouse pointer and 
   save it in the mySelectedNode variable. 
 */
private void treeView1_MouseDown(Object sender,
 
                                 System.Windows.Forms.MouseEventArgs e)
{
    mySelectedNode = treeView1.GetNodeAt(e.get_X(), e.get_Y());
} //treeView1_MouseDown

private void menuItem1_Click(Object sender,
 System.EventArgs e)
{
    if (mySelectedNode != null && mySelectedNode.get_Parent()
 != null) {
        treeView1.set_SelectedNode(mySelectedNode);
        treeView1.set_LabelEdit(true);
        if (!(mySelectedNode.get_IsEditing())) {
            mySelectedNode.BeginEdit();
        }
    }
    else {
        MessageBox.Show("No tree node selected or selected node"
            + "is a root node.\n" 
            + "Editing of root nodes is not allowed.", "Invalid selection");
    }
} //menuItem1_Click

private void treeView1_AfterLabelEdit(Object
 sender, 
                            System.Windows.Forms.NodeLabelEditEventArgs e)
{
    if (e.get_Label()!= null) {
        if (e.get_Label().length() > 0) {
            if (e.get_Label().IndexOfAny((new
 char[]{ '@', '.', ',', '!' }))
                == -1) {
                // Stop editing without canceling the label change.
                e.get_Node().EndEdit(false);
            }
            else {
                /* Cancel the label edit action, inform the user, and 
                   place the node in edit mode again. 
                 */
                e.set_CancelEdit(true);
                MessageBox.Show("Invalid tree node label.\n" 
                    + "The invalid characters are: "
                    + "'@','.', ',', '!'", "Node Label Edit");
                e.get_Node().BeginEdit();
            }
        }
        else {
            /* Cancel the label edit action, inform the user, and 
               place the node in edit mode again.
             */
            e.set_CancelEdit(true);
            MessageBox.Show("Invalid tree node label.\n"
                + "The label cannot be blank", "Node Label Edit");
            e.get_Node().BeginEdit();
        }
        this.treeView1.set_LabelEdit(false);
    }
} //treeView1_AfterLabelEdit