关于winform窗体跳转的问题

Question

两个窗体A和B，从A的两个按钮都可以跳转到B，怎么判断点了哪个按钮进入的B窗体。求详细过程代码

Answer 1

A窗体
private void button2_Click(object sender, EventArgs e)
{
Common.A = "btn2";
Form2 f = new Form2();
f.Show();
}

    private void button1_Click(object sender, EventArgs e)
    {
        Common.A = "btn1";
        Form2 f = new Form2();
        f.Show();
    }
            B窗体

             private void Form2_Load(object sender, EventArgs e)
    {
        if (Common.A == "btn1")
        {
            MessageBox.Show("button1");
        }
        else
        {
            MessageBox.Show("button2");
        }
    }

            Common类
              public  class Common
{
   public static string A;
}