@Robin_Shen Thanks for you reply.
I referred to the example and just reconfigured it.

At first, I had no clue how to set the second parameter of Adc_Sar_Ip_GetConvData, so it only returned 0.
And now I know how to set it based on different channles and I can read specific values from it, but the values I read are usually over 4095.
Precise ADC is 12-bit binary number which is 4095 at max.
Why is it over 4095? Is there any conversion about it?
Thanks.