private void button2_Click(object sender, EventArgs e)
{
this.Hide();
Form8 sistema = new Form8();
sistema.ShowDialog();
this.Close();
}
private void 择题删除ToolStripMenuItem_Click(object sender, EventArgs e)
{
this.Visible = false;
Form8 f8 = new Form8();
f8.ShowDialog();
this.Hide();
this.Visible = true;
}