C#点击按钮时label可见，再次点击label不可见

C#点击按钮bu_1时label可见，再次点击label不可见

eg:
private bool kong = true;

private void bu_1_Click(object sender, EventArgs e)
{
label.Visible = kong;
bool tmp = kong;
if (tmp==true)
{
kong = false;
}
if (tmp == false)
{
kong = true;
}
}