const int WM_SYSCOMMAND = 0x112;
const int SC_CLOSE = 0xF060;
const int SC_MINIMIZE = 0xF020;
const int SC_MAXIMIZE = 0xF030;
protected override void WndProc(ref Message m)
{
    if (m.Msg == WM_SYSCOMMAND)
    {
        if (m.WParam.ToInt32() == SC_MINIMIZE) //是否点击最小化
        {

            //这里写操作代码
            this.Visible = false; //隐藏窗体
            return;
        }


        if (m.WParam.ToInt32() == SC_MAXIMIZE )

        { //..................... }

       

        if (m.WParam.ToInt32() == SC_CLOSE )

        {   //.....................}


    }
    base.WndProc(ref m);
}

//这个功能是 捕获最小化按钮事件 ,隐藏当前窗体.