private void button1_Click(object sender, EventArgs e)
        {
            CheckBox CheckName = new CheckBox();
            CheckName.Text = "检查";
            CheckName.Checked = true;
            CheckName.Location = new Point(20, 20);
            groupBox1.Controls.Add(CheckName);
        }

------解决方案--------------------
load
在窗体Show()实执行
Activated 
窗体被激活执行
FormClosing
窗体关闭中执行
FormClosed
关闭后执行
Dispose 
最后释放资源