右键弹出菜单 并动态新增菜单子项

private void vAssetDetailDataGridView_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
if (e.RowIndex >= 0)
{
if (vAssetDetailDataGridView.Rows[e.RowIndex].Selected == false)
{
vAssetDetailDataGridView.ClearSelection();
vAssetDetailDataGridView.Rows[e.RowIndex].Selected = true;
}
string typename = vAssetDetailDataGridView.Rows[e.RowIndex].Cells[0].Value.ToString();
AssetType listtype = AssetTypeBLL.QueryAllAssetType().FirstOrDefault<AssetType>(p => p.TypeName == typename) as AssetType;

if (listtype != null)
{
List<AssetTypeExtend> listextend = AssetTypeBLL.QueryAssetTypeExtend(listtype.Id);
cmsTypeExtend.Items.Clear();
for (int i = 0; i < listextend.Count; i++)
{
cmsTypeExtend.Items.Add(listextend[i].ExtendName);
}
}
else
{
cmsTypeExtend.Text = "暂无属性";
}

cmsTypeExtend.Show(MousePosition.X, MousePosition.Y);
}
}
}