窗口1 的代码
namespace HistoryGame
{

    public delegate void CloseForm();  

    public partial class FrmSuspend : Form
    {
        

        public FrmSuspend()
        {
            InitializeComponent();
        }
        public event CloseForm FrmSuspendClose;  

        public void picContinue_Click(object sender, EventArgs e)
        {
            FrmSuspendClose();
        }
窗体2
namespace HistoryGame
{
    public partial class FrmSuspendCopy : Form
    {
        public FrmSuspendCopy()
        {
            InitializeComponent();
        }

        FrmSuspend frc = new FrmSuspend();

        void CloseBySuspend(bool topmost)
        {
            this.DialogResult = DialogResult.OK;
            this.Close();
        }

        private void FrmSuspendCopy_Load(object sender, EventArgs e)
        {
        }
        private void pictureBox1_Click(object sender, EventArgs e)
        {
            frc.FrmSuspendClose += new CloseForm(CloseBySuspend);
        }
    }
}

为什么窗体1单击后出现
 FrmSuspendClose(); 未进行实例化。的错误，请问什么情况。

namespace HistoryGame
{
    public partial class FrmSuspendCopy : Form
    {
        public FrmSuspendCopy()
        {
            InitializeComponent();
        }

        FrmSuspend frc = new FrmSuspend();

        void CloseBySuspend(bool topmost)
        {
            this.DialogResult = DialogResult.OK;
            this.Close();
        }

        private void FrmSuspendCopy_Load(object sender, EventArgs e)
        {
          frc.FrmSuspendClose += new CloseForm(CloseBySuspend);
        }

        private void pictureBox1_Click(object sender, EventArgs e)
        {
         
        }
    }
}

------解决方案--------------------

窗体 1中  FrmSuspendClose () 实例在哪?  //就是这个frc.FrmSuspendClose += new CloseForm(CloseBySuspend);

       void CloseBySuspend(bool topmost)
       {
           this.DialogResult = DialogResult.OK;
           this.Close();
       }
这个改成 public  然后在 窗体1中 绑定到 FrmSuspendClose 上