DirectShowLib - 无法使用网络摄像头拍摄多张照片.得到"没有足够的系统资源来完成所请求的服务"错误

Question

我正在使用Visual Studio 2012并使用C#,我正在使用库DirectShowLib从我的网络摄像头拍摄照片,但我只能拍一张照片,如果我尝试再拍一张照片,我会得到一个例外:

   DirectShowLib.DsError.ThrowExceptionForHR(Int32 hr)
   at SnapShot.Capture.SetupGraph(DsDevice dev, Int32 iWidth, Int32 iHeight, Int16 iBPP, Control hControl) in c:\Users\devel_000\Documents\Visual Studio 2012\Projects\ControlAcceso\ControlAcceso\Capture.cs:line 323
   at SnapShot.Capture..ctor(Int32 iDeviceNum, Int32 iWidth, Int32 iHeight, Int16 iBPP, Control hControl) in c:\Users\devel_000\Documents\Visual Studio 2012\Projects\ControlAcceso\ControlAcceso\Capture.cs:line 86
   at ControlAcceso.PhotoWindow..ctor() in c:\Users\devel_000\Documents\Visual Studio 2012\Projects\ControlAcceso\ControlAcceso\PhotoWindow.cs:line 32
   at ControlAcceso.CheckWindow.pbPhoto_Click(Object sender, EventArgs e) in c:\Users\devel_000\Documents\Visual Studio 2012\Projects\ControlAcceso\ControlAcceso\CheckWindow.cs:line 108
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at ControlAcceso.Program.Main() in c:\Users\devel_000\Documents\Visual Studio 2012\Projects\ControlAcceso\ControlAcceso\Program.cs:line 18
   at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
   at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

我正在使用DxSnap示例[link]拍摄照片.方法SetupGraph抛出异常[link]

这条线DirectShowLib.DsError.ThrowExceptionForHR(Int32 hr)引起了我的注意,这是什么意思？我怎样才能解决这个问题？

Answer 1

该错误-2147023446是0x800705AA,ERROR_NO_SYSTEM_RESOURCES"存在不足的系统资源完成所请求的服务." (请参阅此文章和工具,HRESULT轻松方便地阅读数值).

我想说你最有可能试图打开第二个管道而不先关闭.并且视频捕获设备是专门打开的,因此如果还有另一个仍处于活动状态,则无法启动管道.错误代码正是这样建议的.

为了解决这个问题,您需要确保调用IMediaControl.Stop之前的过滤器图,并释放不再需要的COM接口Marshal.ReleaseComObject.