private void mCaiDat_Click(object sender, EventArgs e)
{
lblTieuDe.Text = "Cài đặt";
Cursor.Current = Cursors.WaitCursor;
XuLyChuyenForm();
FrmCaiDat m_frmCaiDat = FrmCaiDat.Instance;
f = m_frmCaiDat;
m_frmCaiDat.MdiParent = this;
m_frmCaiDat.Dock = DockStyle.Fill;
m_frmCaiDat.Show();
}
private void FrmCaiDat_FormClosed(object sender, FormClosedEventArgs e)
{
_Instance = null;
}