WindowsPhone 8.1 FlashLight

Question

我有诺基亚730，我想让FlashLight工作。但下一个代码崩溃：

     MediaCapture mc = new MediaCapture();
        await mc.InitializeAsync();

            if (mc.VideoDeviceController.TorchControl.Supported == true)
            {
                mc.VideoDeviceController.TorchControl.Enabled = true;
                mc.VideoDeviceController.TorchControl.PowerPercent = 100; // here is crash
            }

有什么想法吗？出于某些原因，使用较旧平台（wp 7，wp8）的解决方案根本不起作用。

Answer 1

通过下一个代码修复它：

X Error of failed request:  BadIDChoice (invalid resource ID chosen for this connection)
  Major opcode of failed request:  148 (RENDER)
  Minor opcode of failed request:  4 (RenderCreatePicture)

但出于某种原因，我应该在启用TorchControl之前等待500毫秒。有人可以解释原因吗？

Answer 2

根据this post，可以尝试以下方法：

//to switch OFF flash light
mc.VideoDeviceController.FlashControl.Enabled = false;
//to switch ON flash light
mc.VideoDeviceController.FlashControl.Enabled = true;