cannot open tx2 onboard camera

i try to open the tx2 onboard camera,like this
but it not working,i have installed opencv3.4.1 for four times. i dont know why ,it makes me crazy

it is error information

VIDEOIO ERROR: V4L: device nvcamerasrc ! video/x-raw(memory:NVMM), width=1280, height=(int)720,format=(string)I420,framerate=(fraction)24/1 ! nvvidconv flip-method=2 ! video/x-raw,format=(string)BGRx ! videoconvert ! video/x-raw, format=(string)BGR ! appsink: Unable to query number of channels
Failed to open camera.

help !!

Please refer to this thread, if you confirm your onboard camera is working fine.