DataGridViewのセルフォントを変更する方法

DataGridViewのセルフォントを変更する方法
VB.NET

Private defaultCellStyle As DataGridViewCellStyle
Private mouseCellStyle As DataGridViewCellStyle

Private Sub Form1_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load
    Me.defaultCellStyle = New DataGridViewCellStyle()
    Me.mouseCellStyle = New DataGridViewCellStyle()
    Me.mouseCellStyle.Font = New Font(dgv1.Font, _
        dgv1.Font.Style Or FontStyle.Bold)
End Sub

Private Sub dgv1_CellMouseEnter(ByVal sender As Object, _
        ByVal e As DataGridViewCellEventArgs) _
        Handles dgv1.CellMouseEnter
    If e.ColumnIndex >= 0 And e.RowIndex >= 0 Then
        Dim dgv As DataGridView = CType(sender, DataGridView)
        dgv(e.ColumnIndex, e.RowIndex).Style = Me.mouseCellStyle
    End If
End Sub

Private Sub dgv1_CellMouseLeave(ByVal sender As Object, _
        ByVal e As DataGridViewCellEventArgs) _
        Handles dgv1.CellMouseLeave
    If e.ColumnIndex >= 0 And e.RowIndex >= 0 Then
        Dim dgv As DataGridView = CType(sender, DataGridView)
        dgv(e.ColumnIndex, e.RowIndex).Style = Me.defaultCellStyle
    End If
End Sub

C#

private DataGridViewCellStyle defaultCellStyle;
private DataGridViewCellStyle mouseCellStyle;

private void Form1_Load(object sender, EventArgs e)
{
    this.defaultCellStyle = new DataGridViewCellStyle();
    this.mouseCellStyle = new DataGridViewCellStyle();
    this.mouseCellStyle.Font = new Font(dgv1.Font,
        dgv1.Font.Style | FontStyle.Bold);
}

private void dgv1_CellEnter(object sender,
    DataGridViewCellEventArgs e)
{
    if (e.ColumnIndex >= 0 && e.RowIndex >= 0)
    {
        DataGridView dgv = (DataGridView)sender;
        dgv[e.ColumnIndex, e.RowIndex].Style = this.mouseCellStyle;
    }
}

private void dgv1_CellLeave(object sender,
    DataGridViewCellEventArgs e)
{
    if (e.ColumnIndex >= 0 && e.RowIndex >= 0)
    {
        DataGridView dgv = (DataGridView)sender;
        dgv[e.ColumnIndex, e.RowIndex].Style = this.defaultCellStyle;
    }
}