iOS中使用位运算判断权限

在iOS的某些权限判断中，使用位运算可以起到很方便快捷的作用，示例代码：

 if ([OCTAuthorityManager authorityOfUser] & OCTInspectionAuthorityTransferAdd || [OCTAuthorityManager authorityOfUser] & OCTInspectionAuthorityDiaryAdd || [OCTAuthorityManager authorityOfUser] & OCTInspectionAuthorityAddNotice || [OCTAuthorityManager authorityOfUser] & OCTInspectionAuthorityAddRepair) {
            //根据不同的权限，设置不同的显示界面
            //code
        }

其中[OCTAuthorityManager authorityOfUser] 是给不同的职位返回各自不同的权限枚举值：

+ (OCTInspectionAuthority)authorityOfUser{
    OCTUserModel *shareUser = [OCTUserModel shareUser];
    if (!shareUser.userPostId || 0 == shareUser.userPostId.length) {
        return OCTInspectionAuthorityNone;
    }
    NSInteger postId = shareUser.userPostId.integerValue;
#if DEBUG
    //return OCTInspectionAuthorityAll;
#endif    
    if (0 == postId) {
        return OCTInspectionAuthorityAll;
    }else if (OCTPostViceManager == postId){
        //副总经理
        return OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityAddNotice | OCTInspectionAuthorityCheckRunningRecord | OCTInspectionAuthorityCheckInspection | OCTInspectionAuthorityCheckTrouble;
    }
    if ([shareUser.userDepartmentId hasPrefix:OCTTouristDepartmentPrefix]) {
        //游客部
        switch (postId) {
            case OCTPostOperator:
                //操作员
                return OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityAddTransfer| OCTInspectionAuthorityCheckRunningRecord| OCTInspectionAuthorityAddRunningRecord;
            case OCTPostForeman:
                //领班
                return OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityAddNotice | OCTInspectionAuthorityCheckRunningRecord;
            case OCTPostCharge:
                //主管
                return OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityAddNotice | OCTInspectionAuthorityCheckRunningRecord;
            case OCTPostHeader:
                //部长
                return OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityAddNotice | OCTInspectionAuthorityCheckRunningRecord;
            case OCTPostOther:
                //其他
                return OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityCheckRunningRecord;
            default:
                break;
        }
    }else if ([shareUser.userDepartmentId hasPrefix:OCTTechnologyDepartmentPrefix]){
        //技术部
        switch (postId) {
            case OCTPostFixer:
                //操作员
                return OCTInspectionAuthorityCheckInspection | OCTInspectionAuthorityAddInspection | OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityCheckTrouble |OCTInspectionAuthorityAddRepair | OCTInspectionAuthorityFixDone;
            case OCTPostForeman:
                //领班
                return OCTInspectionAuthorityCheckInspection | OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityCheckTrouble |OCTInspectionAuthorityAddNotice | OCTInspectionAuthorityAddInspection | OCTInspectionAuthorityExamineInspection;
            case OCTPostEngineer:
            case OCTPostCharge:
                //主管
                return OCTInspectionAuthorityCheckInspection | OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityCheckTrouble |OCTInspectionAuthorityAddNotice | OCTInspectionAuthorityExamineInspection;
            case OCTPostHeader:
                //部长
                return OCTInspectionAuthorityCheckInspection | OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityCheckTrouble | OCTInspectionAuthorityAddNotice;
            case OCTPostOther:
                //其他
                return OCTInspectionAuthorityCheckInspection | OCTInspectionAuthorityCheckTransfer | OCTInspectionAuthorityCheckTrouble;
            default:
                break;
        }
    }else if ([shareUser.userDepartmentId hasPrefix:OCTTubeDepartmentPrefix]){
        switch (postId) {
            case OCTPostFixer:
                //操作员
                return  OCTInspectionAuthorityLookUp |OCTInspectionAuthorityInspectNewlyAdded |OCTInspectionAuthorityTransferLookUp|
                        OCTInspectionAuthorityTransferAdd |OCTInspectionAuthorityDiaryLookUp|OCTInspectionAuthorityDiaryAdd;
            case OCTPostForeman:
                //领班
                return  OCTInspectionAuthorityLookUp |OCTInspectionAuthorityInspectNewlyAdded |OCTInspectionAuthorityTransferLookUp|
                        OCTInspectionAuthorityTransferAdd |OCTInspectionAuthorityDiaryLookUp|OCTInspectionAuthorityDiaryAdd;
                
            case OCTPostEngineer:
            case OCTPostCharge:
                //主管
                return OCTInspectionAuthorityLookUp |OCTInspectionAuthorityTransferLookUp|OCTInspectionAuthorityDiaryLookUp;
                
            case OCTPostHeader:
                //部长
                return OCTInspectionAuthorityLookUp |OCTInspectionAuthorityTransferLookUp|OCTInspectionAuthorityDiaryLookUp;

            case OCTPostOther:
                //其他
                return OCTInspectionAuthorityLookUp |OCTInspectionAuthorityTransferLookUp|OCTInspectionAuthorityDiaryLookUp;

            default:
                return  OCTInspectionAuthorityLookUp |OCTInspectionAuthorityInspectNewlyAdded |OCTInspectionAuthorityTransferLookUp|
                OCTInspectionAuthorityTransferAdd |OCTInspectionAuthorityDiaryLookUp|OCTInspectionAuthorityDiaryAdd;
        }
|OCTInspectionAuthorityDiaryLookUp|OCTInspectionAuthorityDiaryAdd;
    }
    return OCTInspectionAuthorityNone;
}

相关枚举值如下：

typedef NS_ENUM(NSUInteger,OCTInspectionAuthority){
    OCTInspectionAuthorityNone = 0,        //没有权限
    OCTInspectionAuthorityAddInspection = 1 << 0,    //添加日周月检
    OCTInspectionAuthorityCheckInspection = 1 << 1, //查看日周月检
    OCTInspectionAuthorityExamineInspection = 1 << 2, //审核日周月间
    OCTInspectionAuthorityCheckTransfer = 1 << 3,  //查看操作故障移交
    OCTInspectionAuthorityCheckTrouble = 1 << 4, //查看操作故障列表
    OCTInspectionAuthorityAddTransfer = 1 << 5, //新增故障移交
    OCTInspectionAuthorityAddRepair = 1 << 6,  //新增故障维修
    OCTInspectionAuthorityAddNotice = 1 << 7,  //新增公告
    OCTInspectionAuthorityCheckRunningRecord = 1 << 8, //运行记录权限
    OCTInspectionAuthorityAddRunningRecord = 1 << 9,    //新增运行记录权限
    OCTInspectionAuthorityFixDone = 1 << 10,            //完成维修权限
    OCTInspectionAuthorityLookUp= 1 << 11,              //物管检查列表查看
    OCTInspectionAuthorityInspectNewlyAdded= 1 << 12,   //物管检查列表新增
    OCTInspectionAuthorityTransferLookUp= 1 << 13,      //故障维修查看
    OCTInspectionAuthorityTransferAdd= 1 << 14,         //故障维修新增
    OCTInspectionAuthorityDiaryLookUp= 1 << 15,         //值班日志查看
    OCTInspectionAuthorityDiaryAdd= 1 << 16,            //值班日志新增
    
    OCTInspectionAuthorityAll = OCTInspectionAuthorityAddInspection |
    OCTInspectionAuthorityCheckInspection |
    OCTInspectionAuthorityExamineInspection |
    OCTInspectionAuthorityCheckTransfer |
    OCTInspectionAuthorityCheckTrouble |
    OCTInspectionAuthorityAddTransfer |
    OCTInspectionAuthorityAddRepair |
    OCTInspectionAuthorityAddNotice |
    OCTInspectionAuthorityCheckRunningRecord |
    OCTInspectionAuthorityAddRunningRecord |
    OCTInspectionAuthorityFixDone |
    OCTInspectionAuthorityLookUp |
    OCTInspectionAuthorityInspectNewlyAdded |
    OCTInspectionAuthorityTransferLookUp |
    OCTInspectionAuthorityTransferAdd |
    OCTInspectionAuthorityDiaryLookUp |
    OCTInspectionAuthorityDiaryAdd //全部权限
};

附：整数在计算机中用二进制的位来表示，C语言提供一些运算符可以直接操作整数中的位，称为位运算，这些运算符的操作数都必须是整型的。

 & 按位与,   | 按位或 ,  ^ 按位异或
1 & 1 = 1， 1 | 1 = 1， 1 ^ 1 = 0
1 & 0 = 0， 1 | 0 = 1， 1 ^ 0 = 1
0 & 1 = 0， 0 | 1 = 1， 0 ^ 1 = 1
0 & 0 = 0， 0 | 0 = 0， 0 ^ 0 = 0