C#panel控件问题

在FORM1 里有个 panel 和3个button 我想点击butto1 就在panel显示FORM2 button2就显示FORM2

 

private void button1_Click(object sender, EventArgs e)
{
    Form f = new Form1();
    this.ShowFormInPanel(f, this.panel1);
}
private void button2_Click(object sender, EventArgs e)
{
    Form f = new Form2();
    this.ShowFormInPanel(f, this.panel1);
}

private void button3_Click(object sender, EventArgs e)
{
    Form f = new Form3();
    this.ShowFormInPanel(f, this.panel1);
}

private void ShowFormInPanel(Form f, Panel AParent)
{
   
    f.Top = 0;
    f.Left = 0;
    f.TopLevel = false;

    // f.FormBorderStyle = FormBorderStyle.None;
    AParent.Controls.Add(f);
    // f.Parent = AParent;
    // f.Dock = DockStyle.Fill;
    f.Show();
    // f.BringToFront();
    // f.Focus();
}