樹莓派3，win10 Iot，串口開發，抄例子，串口獲取返回老是null，例子卻可以，代碼一樣，上網查詢結果如下：

https://stackoverflow.com/questions/34160376/windows-universal-app-serial-ports-wont-open-serialdevice-fromidasync-always-n

So Microsoft do not mention that you need to add something to the app manifest for serial communication nor is there a tick box in the app manifest GUI for serial communication.

The following needs to be added to your app manifest (create the <Capabilities> section if it doesn‘t exist):

<Capabilities>
  <DeviceCapability Name="serialcommunication">
    <Device Id="any">
      <Function Type="name:serialPort" />
    </Device>
  </DeviceCapability>
</Capabilities>
 

UPDATE 10/2016

Microsoft have updated their documentation to reflect this requirement.

https://msdn.microsoft.com/en-us/library/windows/apps/windows.devices.serialcommunication.aspx

記錄並轉載

win10 IoT開發 Serial?Device 返回 null