C# 念让子窗体随主窗体移动而移动

C# 想让子窗体随主窗体移动而移动
就在 private void button1_Click(object sender, EventArgs e)
  {
  Form f = new Form2();
  f.Show();//弹出form2
  f.StartPosition = FormStartPosition.Manual;
  f.Left = this.Left + this.Width;
  f.Top = this.Top;//设置form2位置
   
  }

  private void Form1_Move(object sender, EventArgs e)
  {
  Form f = new Form2();
  f.Location = new Point(this.Location.X + this.Width, this.Location.Y);//form2随着form1移动
   
  }
不知道为什么不正确，只能实现form2挨着form1 不能随其form1移动而移动
请哪位大神帮忙改下，让我能实现这个功能！！！

[解决办法]

C# code

Form f = new Form2();private void button1_Click(object sender, EventArgs e)  {  f.Show();//弹出form2  f.StartPosition = FormStartPosition.Manual;  f.Left = this.Left + this.Width;  f.Top = this.Top;//设置form2位置      }  private void Form1_Move(object sender, EventArgs e)  {  f.Location = new Point(this.Location.X + this.Width, this.Location.Y);//form2随着form1移动      }