OC枚举之妙用

使用枚举来定义内容和顺序
代码如下：
定义：

//内容
typedef NS_OPTIONS(NSUInteger, ContentType) {
    A1 = 1,
    A2 = 2,
    A3 = 3,
    A4 = 4,
    A5 = 5,
    A6 = 6,
    A7 = 7,
    A8 = 8
};

//顺序
typedef NS_OPTIONS(NSUInteger, PositionType) {
    P1 = 0xF0000000,
    P2 = 0x0F000000,
    P3 = 0x00F00000,
    P4 = 0x000F0000,
    P5 = 0x0000F000,
    P6 = 0x00000F00,
    P7 = 0x000000F0,
    P8 = 0x0000000F
};

使用：
NSUInteger testNumber1 = (A1 << 28) | (A4 << 24) | (A2 << 20) | (A7 << 16) | (A3 << 12) | (A8 << 8) | (A6 << 4) | (A5 << 0);

解析

    NSString *positionNumber1 = [self valueOnPosition:testNumber1 position:P1];
    NSString *positionNumber2 = [self valueOnPosition:testNumber1 position:P2];
    NSString *positionNumber3 = [self valueOnPosition:testNumber1 position:P3];
    NSString *positionNumber4 = [self valueOnPosition:testNumber1 position:P4];
    NSString *positionNumber5 = [self valueOnPosition:testNumber1 position:P5];
    NSString *positionNumber6 = [self valueOnPosition:testNumber1 position:P6];
    NSString *positionNumber7 = [self valueOnPosition:testNumber1 position:P7];
    NSString *positionNumber8 = [self valueOnPosition:testNumber1 position:P8];
    
    NSLog(@"positionNumber1 : %@, \npositionNumber2 : %@, \npositionNumber3 : %@, \npositionNumber4 : %@, \npositionNumber5 : %@, \npositionNumber6 : %@, \npositionNumber7 : %@, \npositionNumber8 : %@", positionNumber1, positionNumber2, positionNumber3, positionNumber4, positionNumber5, positionNumber6, positionNumber7, positionNumber8);

- (NSString *)valueOnPosition:(NSUInteger)number position:(NSUInteger)position{
    
    NSUInteger contentNumber = position & number;
    

    switch (position) {
        case P1:
            contentNumber = contentNumber >> 28;
            break;
        case P2:
            contentNumber = contentNumber >> 24;
            break;
        case P3:
            contentNumber = contentNumber >> 20;
            break;
        case P4:
            contentNumber = contentNumber >> 16;
            break;
        case P5:
            contentNumber = contentNumber >> 12;
            break;
        case P6:
            contentNumber = contentNumber >> 8;
            break;
        case P7:
            contentNumber = contentNumber >> 4;
            break;
        case P8:
            contentNumber = contentNumber >> 0;
            break;
            
        default:
            break;
    }
    
    return [self getValue:contentNumber];
}

- (NSString *)getValue:(NSUInteger)number{
    if (number == A1) {
        return @"A1";
    }else if (number == A2){
        return @"A2";
    }else if (number == A3){
        return @"A3";
    }else if (number == A4){
        return @"A4";
    }else if (number == A5){
        return @"A5";
    }else if (number == A6){
        return @"A6";
    }else if (number == A7){
        return @"A7";
    }else if (number == A8){
        return @"A8";
    }
    return @"unknown";
}