问题描述
我正在使用Visual Studio 2012并使用C#，正在使用DirectShowLib库从网络摄像头拍摄照片，但是我只能拍摄一张照片，如果尝试拍摄另一张照片，我会遇到异常:
I'm working on Visual Studio 2012 and using C#, I'm using the library DirectShowLib to take pictures from my webcam, but I can only take one picture, if I try to take another one I get an exception:
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 [链接] 到拍照.该异常会在SetupGraph [link]
I'm using the DxSnap example [link] to take the pictures. the exception is thrown in the method SetupGraph [link]
DirectShowLib.DsError.ThrowExceptionForHR(Int32 hr)行引起了我的注意，这是什么意思?我该如何解决?
The line DirectShowLib.DsError.ThrowExceptionForHR(Int32 hr) caught my attention, what does it mean? How can I fix this?
推荐答案
错误-2147023446是0x800705AA，ERROR_NO_SYSTEM_RESOURCES系统资源不足，无法完成请求的服务." (请参阅这篇文章和工具，以轻松便捷的方式读取HRESULT值).
The error -2147023446 is 0x800705AA, ERROR_NO_SYSTEM_RESOURCES "Insufficient system resources exist to complete the requested service." (see this post and tool on reading HRESULT values easily and in convenient way).
我会说您很可能在尝试打开第二条管道而不先关闭.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，则您将无法启动管道.错误代码正好说明了这一点.
I would say most likely you are trying to open second pipeline without closing first. And video capture devices are opened exclusively, hence you cannot start a pipeline if there is another one still active. The error code is suggesting exactly this.
要变通解决此问题，您需要确保在上一个过滤器图上调用IMediaControl.Stop，并使用Marshal.ReleaseComObject释放不再需要的COM接口.
In order to work this around, you need to make sure you call IMediaControl.Stop on previous filter graph, and release COM interfaces you don't need anymore with Marshal.ReleaseComObject.
这篇关于DirectShowLib-使用网络摄像头不能拍摄多张照片.得到“存在不足的系统资源来完成所请求的服务".错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！