Android app get permission to judge

This is the permission that is applied to the android6.0 version above, to determine whether you have this permission and how to obtain permissions:

Determine if you have permissions
@Override
public void Onrequestpermissionsresult (int requestcode,
                                       string[] Permissions,
                                       Int[] grantresults) {

    If the request code is the same as the definition, the per_req_code here is a number that is defined by itself and can be defined arbitrarily.
    if (Requestcode==per_req_code) {
        if (grantresults!=null&&grantresults.length>0) {
            if (grantresults[0]==packagemanager.permission_granted) {
                Readinfor ();
            }else {
                Toast.maketext (Contantsactivity.this, "No Permissions", Toast.length_short). Show ();
            }
        }
    }
}

Action to request permission:

if (build.version.sdk_int>=build.version_codes. M) {
        Determine if there is permission
        int flag = Activitycompat.checkselfpermission (
                Contantsactivity.this,
                Android. Manifest.permission.READ_CONTACTS);
        if (flag!= packagemanager.permission_granted) {//No permissions
            Request permission
            Activitycompat.requestpermissions (
                    contantsactivity.this,//context
                    New String[]{android. manifest.permission.read_contacts},//What permissions are requested
                    per_req_code//Request Code
            );
        }else {
           Perform an action with permission
        }
    }else {
       Perform an action with permission
    }
}

Android app get permission to judge