Why does Xiaomi 5X's calendar need to read SMS and contacts, and it can't be uninstalled?

Hello, OPPO software permission setting method:

1, ColorOS 3.0 system, enter the mobile phone housekeeper-rights privacy-application rights management-applications that need to modify rights to modify;

2.ColorOS version 2. 1, Security Center-Rights Privacy-Application Rights Management;

3.ColorOS version, security center-rights management-application rights management;

4. Other versions, Settings-Security Service-Personal Information Security.