海康卫视 NET_DVR_FindFile NET_DVR_PlayBackByTime 尝试读取或写入受保护的内存，这通常指示其他内存已损坏

从农民伯伯那下载的代码

NET_DVR_PlayBackByTime NET_DVR_FindFile 这两个方法执行不了

下面是我改的 经过测试了

[DllImport("HCNetSDK.dll")]

public static extern int NET_DVR_PlayBackByTime(int lUserID, int lChannel, ref NET_DVR_TIME lpStartTime, ref NET_DVR_TIME lpStopTime, IntPtr hWnd);

[DllImport("HCNetSDK.dll")]

public static extern int NET_DVR_FindFile(int lUserID, int lChannel, uint dwFileType,ref NET_DVR_TIME lpStartTime,ref NET_DVR_TIME lpStopTime);

[DllImport("HCNetSDK.dll")] 

public static extern int NET_DVR_PlayBackByTime(int lUserID, int lChannel, ref NET_DVR_TIME lpStartTime, ref NET_DVR_TIME lpStopTime, IntPtr hWnd); 

[DllImport("HCNetSDK.dll")]

 public static extern int NET_DVR_FindFile(int lUserID, int lChannel, uint dwFileType,ref NET_DVR_TIME lpStartTime,ref NET_DVR_TIME lpStopTime);