private void tsbAddStudent_Click(object sender, EventArgs e)
{
if (objFrmAddStudent == null)
{
objFrmAddStudent = new FrmAddStudent();
objFrmAddStudent.Show();//show this windows
}
else
{
objFrmAddStudent.Activate();
objFrmAddStudent.WindowState = FormWindowState.Normal;
}
}
//怎样保证对象的唯一性
private void tsmiAddStudent_Click(object sender, EventArgs e)
{
if (objFrmAddStudent == null)
{
objFrmAddStudent = new FrmAddStudent();
objFrmAddStudent.Show();
}
else
{
objFrmAddStudent.Activate();//激活只能在最小化的时候起作用
objFrmAddStudent.WindowState = FormWindowState.Normal;
}
}