DataGridView.CellMouseEnter Event     
Definition
Important
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Occurs when the mouse pointer enters a cell.
public:
 event System::Windows::Forms::DataGridViewCellEventHandler ^ CellMouseEnter;public event System.Windows.Forms.DataGridViewCellEventHandler CellMouseEnter;public event System.Windows.Forms.DataGridViewCellEventHandler? CellMouseEnter;member this.CellMouseEnter : System.Windows.Forms.DataGridViewCellEventHandler Public Custom Event CellMouseEnter As DataGridViewCellEventHandler Event Type
Examples
The following code example shows a CellMouseEnter event handler in a Tic-Tac-Toe game implementation that uses image columns in a DataGridView control. The event handler uses the cell value to determine the cursor and ToolTip to display.
This code is part of a larger example shown in How to: Work with Image Columns in the Windows Forms DataGridView Control.
void dataGridView1_CellMouseEnter( Object^ sender, DataGridViewCellEventArgs^ e )
{
   Bitmap^ markingUnderMouse = dynamic_cast<Bitmap^>(dataGridView1->Rows[ e->RowIndex ]->Cells[ e->ColumnIndex ]->Value);
   if ( markingUnderMouse == blank )
   {
      dataGridView1->Cursor = Cursors::Default;
   }
   else
   if ( markingUnderMouse == o || markingUnderMouse == x )
   {
      dataGridView1->Cursor = Cursors::No;
      ToolTip(e,true);
   }
}
void ToolTip( DataGridViewCellEventArgs^ e, bool showTip )
{
   DataGridViewImageCell^ cell = dynamic_cast<DataGridViewImageCell^>(dataGridView1->Rows[ e->RowIndex ]->Cells[ e->ColumnIndex ]);
   DataGridViewImageColumn^ imageColumn = dynamic_cast<DataGridViewImageColumn^>(dataGridView1->Columns[ cell->ColumnIndex ]);
   if ( showTip )
         cell->ToolTipText = imageColumn->Description;
   else
   {
      cell->ToolTipText = String::Empty;
   }
}
void dataGridView1_CellMouseLeave( Object^ sender, DataGridViewCellEventArgs^ e )
{
   ToolTip( e, false );
   dataGridView1->Cursor = Cursors::Default;
}
private void dataGridView1_CellMouseEnter(object sender,
    DataGridViewCellEventArgs e)
{
    Bitmap markingUnderMouse = (Bitmap)dataGridView1.
           Rows[e.RowIndex].
           Cells[e.ColumnIndex].Value;
    if (markingUnderMouse == blank)
    {
        dataGridView1.Cursor = Cursors.Default;
    }
    else if (markingUnderMouse == o || markingUnderMouse == x)
    {
        dataGridView1.Cursor = Cursors.No;
        ToolTip(e, true);
    }
}
private void ToolTip(DataGridViewCellEventArgs e, bool showTip)
{
    DataGridViewImageCell cell = (DataGridViewImageCell)
        dataGridView1
        .Rows[e.RowIndex].Cells[e.ColumnIndex];
    DataGridViewImageColumn imageColumn =
        (DataGridViewImageColumn)
        dataGridView1.Columns[cell.ColumnIndex];
    if (showTip)
    {
        cell.ToolTipText = imageColumn.Description;
    }
    else { cell.ToolTipText = String.Empty; }
}
private void dataGridView1_CellMouseLeave(object sender,
    DataGridViewCellEventArgs e)
{
    ToolTip(e, false);
    dataGridView1.Cursor = Cursors.Default;
}
Private Sub dataGridView1_CellMouseEnter(ByVal sender As Object, _
    ByVal e As DataGridViewCellEventArgs) _
    Handles dataGridView1.CellMouseEnter
    Dim markingUnderMouse As Bitmap = _
        CType(dataGridView1.Rows(e.RowIndex). _
            Cells(e.ColumnIndex).Value, Bitmap)
    If markingUnderMouse Is blank Then
        dataGridView1.Cursor = Cursors.Default
    ElseIf markingUnderMouse Is o OrElse markingUnderMouse Is x Then
        dataGridView1.Cursor = Cursors.No
        ToolTip(e)
    End If
End Sub
Private Sub ToolTip( _
    ByVal e As DataGridViewCellEventArgs)
    Dim cell As DataGridViewImageCell = _
        CType(dataGridView1.Rows(e.RowIndex). _
        Cells(e.ColumnIndex), DataGridViewImageCell)
    Dim imageColumn As DataGridViewImageColumn = _
        CType(dataGridView1.Columns(cell.ColumnIndex), _
        DataGridViewImageColumn)
    cell.ToolTipText = imageColumn.Description
End Sub
Private Sub dataGridView1_CellMouseLeave(ByVal sender As Object, _
    ByVal e As DataGridViewCellEventArgs) _
    Handles dataGridView1.CellMouseLeave
    dataGridView1.Cursor = Cursors.Default
End Sub
Remarks
For more information about how to handle events, see Handling and Raising Events.