private void button8_Click(object sender, EventArgs e)
        {
            FormUserManager fum = new FormUserManager(this);

            fum.Show();
            this.Visible = false;
        }
        private void 系统设置ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FormUserManager fum = new FormUserManager(this);

            fum.Show();
            this.Visible = false;
        }