DataGridViewCellContextMenuStripNeededEventArgs Class
Assembly: System.Windows.Forms (in system.windows.forms.dll)
The CellContextMenuStripNeeded event occurs only when the DataGridView control DataSource property is set or its VirtualMode property is true.
When you handle the CellContextMenuStripNeeded event, the shortcut menu that you specify in the handler is shown whenever the user right-clicks a cell. This is useful when you want to display shortcut menus determined by the current state or value of a cell.
The CellContextMenuStripNeeded event also occurs whenever the value of the DataGridViewCell.ContextMenuStrip property is retrieved, either programmatically or when the user right-clicks the cell.
You can use the ColumnIndex and RowIndex properties to determine the state or value of a cell, and use this information to set the ContextMenuStrip property. This property is initialized with the value of the cell ContextMenuStrip property, which the event value overrides.
Handle the CellContextMenuStripNeeded event when working with large amounts of data to avoid the performance penalties of setting the cell ContextMenuStrip value for multiple cells. For more information, see Best Practices for Scaling the Windows Forms DataGridView Control.
You can also specify shortcut menus for individual rows rather than individual cells by setting the row ContextMenuStrip property or handling the DataGridView control's RowContextMenuStripNeeded event. The cell ContextMenuStrip property setting overrides the row ContextMenuStrip property setting, and the CellContextMenuStripNeeded event overrides both the RowContextMenuStripNeeded event and the row ContextMenuStrip property setting. You can specify a null reference (Nothing in Visual Basic) for a cell shortcut menu, however, to prevent a row shortcut menu from being overridden.
For more information about handling events, see Consuming Events.
The following code example uses the DataGridViewCellContextMenuStripNeededEventArgs class to set the shortcut menu without unsharing the row.
private ToolStripMenuItem wholeTable = new ToolStripMenuItem(); private ToolStripMenuItem lookUp = new ToolStripMenuItem(); private ContextMenuStrip strip; private string cellErrorText; private void dataGridView1_CellContextMenuStripNeeded(object sender, DataGridViewCellContextMenuStripNeededEventArgs e) { cellErrorText = String.Empty; if (strip == null) { strip = new ContextMenuStrip(); lookUp.Text = "Look Up"; wholeTable.Text = "See Whole Table"; strip.Items.Add(lookUp); strip.Items.Add(wholeTable); } e.ContextMenuStrip = strip; } private void wholeTable_Click(object sender, EventArgs e) { dataGridView1.DataSource = Populate("Select * from employees", true); } private DataGridViewCellEventArgs theCellImHoveringOver; private void dataGridView1_CellMouseEnter(object sender, DataGridViewCellEventArgs e) { theCellImHoveringOver = e; } private DataGridViewCellEventArgs cellErrorLocation; private void lookUp_Click(object sender, EventArgs e) { try { dataGridView1.DataSource = Populate("Select * from employees where " + dataGridView1.Columns[theCellImHoveringOver.ColumnIndex].Name + " = '" + dataGridView1.Rows[theCellImHoveringOver.RowIndex]. Cells[theCellImHoveringOver.ColumnIndex].Value + "'", true); } catch (SqlException) { cellErrorText = "Can't look this cell up"; cellErrorLocation = theCellImHoveringOver; } } private void dataGridView1_CellErrorTextNeeded(object sender, DataGridViewCellErrorTextNeededEventArgs e) { if (cellErrorLocation != null) { if (e.ColumnIndex == cellErrorLocation.ColumnIndex && e.RowIndex == cellErrorLocation.RowIndex) { e.ErrorText = cellErrorText; } } } private DataTable Populate(string query, bool resetUnsharedCounter) { if (resetUnsharedCounter) { ResetCounter(); } // Alter the data source as necessary SqlDataAdapter adapter = new SqlDataAdapter(query, new SqlConnection("Integrated Security=SSPI;Persist Security Info=False;" + "Initial Catalog=Northwind;Data Source=localhost")); DataTable table = new DataTable(); table.Locale = System.Globalization.CultureInfo.InvariantCulture; adapter.Fill(table); return table; } private Label count = new Label(); private int unsharedRowCounter; private void ResetCounter() { unsharedRowCounter = 0; count.Text = unsharedRowCounter.ToString(); }
System.EventArgs
System.Windows.Forms.DataGridViewCellEventArgs
System.Windows.Forms.DataGridViewCellContextMenuStripNeededEventArgs
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.Reference
DataGridViewCellContextMenuStripNeededEventArgs MembersSystem.Windows.Forms Namespace
DataGridView
DataGridView.CellContextMenuStripNeeded Event
DataGridView.DataSource Property
DataGridView.VirtualMode Property
DataGridView.OnCellContextMenuStripNeeded
DataGridViewCellContextMenuStripNeededEventHandler
DataGridViewCellContextMenuStripNeededEventArgs.ContextMenuStrip
DataGridViewCell.ContextMenuStrip Property
DataGridView.RowContextMenuStripNeeded Event
DataGridViewRow.ContextMenuStrip
ContextMenuStrip