NSValue （NSNumber）

NSValue.h 中，一般用的不是很多，

注：注意多使用 NSNumber，而且用 @(int); 方法装箱！

注：UIKit 中 IGeometry.h 中对系统的CG系列的结构体有拓展。使用比较方便。

NSValue

• 地址存各种 结构体

    //结构体（可以自己创建）
    CGRect rect = CGRectMake(111, 111, 22, 33);
    //value 保存 rect 的地址（CGRect类型）
    NSValue *rectValue = [NSValue valueWithBytes:&rect objCType:@encode(CGRect)];

    //新newRect
    CGRect newRect;
    //newRect就可以获取 rectValue 中的数据
    [rectValue getValue:&newRect];
    

• 指针

     NSValue* startValue = [NSValue valueWithPointer:@selector(start)];
    // [startValue pointerValue]; // 就对应了 @selector(start);
    
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setFrame:CGRectMake(111, 111, 111, 111)];
    button.backgroundColor = [UIColor redColor];
    [self.view addSubview:button];
    
    [button addTarget:self action:[start pointerValue] forControlEvents:UIControlEventTouchUpInside];
    

• 弱引用

    NSMutableArray *array = [NSMutableArray array];
    
    // button  是一个 obj（假设是弱引用）
    __weak UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.backgroundColor = [UIColor redColor];
    [button setFrame:CGRectMake(111, 111, 111, 111)];
    
    // value  obj
    NSValue *value = [NSValue valueWithNonretainedObject:button];
    [array addObject:value];
    
    NSValue *newValue = [array objectAtIndex:0];
    
    [self.view addSubview:(UIButton *)[newValue nonretainedObjectValue]];

• 获取类型

    NSLog(@"%s",rectValue.objCType);

• 比较

    NSValue *value1 = [NSValue valueWithCGSize:CGSizeMake(11, 11)];
    NSValue *value2 = [NSValue valueWithRange:NSMakeRange(11, 11)];
    
    if ([value1 isEqualToValue:value2]) {
        NSLog(@"same");
    }else{
        NSLog(@"different");
    }

NSNumber

• 实例方法

//实例方法 初始化
- (NSNumber *)initWithChar:(char)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedChar:(unsigned char)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithShort:(short)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedShort:(unsigned short)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithInt:(int)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedInt:(unsigned int)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithLong:(long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedLong:(unsigned long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithLongLong:(long long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedLongLong:(unsigned long long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithFloat:(float)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithDouble:(double)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithBool:(BOOL)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithInteger:(NSInteger)value NS_AVAILABLE(10_5, 2_0) NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedInteger:(NSUInteger)value NS_AVAILABLE(10_5, 2_0) NS_DESIGNATED_INITIALIZER;

• 类方法

+ (NSNumber *)numberWithChar:(char)value;
+ (NSNumber *)numberWithUnsignedChar:(unsigned char)value;
+ (NSNumber *)numberWithShort:(short)value;
+ (NSNumber *)numberWithUnsignedShort:(unsigned short)value;
+ (NSNumber *)numberWithInt:(int)value;
+ (NSNumber *)numberWithUnsignedInt:(unsigned int)value;
+ (NSNumber *)numberWithLong:(long)value;
+ (NSNumber *)numberWithUnsignedLong:(unsigned long)value;
+ (NSNumber *)numberWithLongLong:(long long)value;
+ (NSNumber *)numberWithUnsignedLongLong:(unsigned long long)value;
+ (NSNumber *)numberWithFloat:(float)value;
+ (NSNumber *)numberWithDouble:(double)value;
+ (NSNumber *)numberWithBool:(BOOL)value;
+ (NSNumber *)numberWithInteger:(NSInteger)value NS_AVAILABLE(10_5, 2_0);
+ (NSNumber *)numberWithUnsignedInteger:(NSUInteger)value NS_AVAILABLE(10_5, 2_0);

• 以上创建 基本不用
  使用 @(someThing);// 快速装箱，自动判断类型。

    NSNumber *number = @(1);

• 获取

@property (readonly) char charValue;
@property (readonly) unsigned char unsignedCharValue;
@property (readonly) short shortValue;
@property (readonly) unsigned short unsignedShortValue;
@property (readonly) int intValue;
@property (readonly) unsigned int unsignedIntValue;
@property (readonly) long longValue;
@property (readonly) unsigned long unsignedLongValue;
@property (readonly) long long longLongValue;
@property (readonly) unsigned long long unsignedLongLongValue;
@property (readonly) float floatValue;
@property (readonly) double doubleValue;
@property (readonly) BOOL boolValue;
@property (readonly) NSInteger integerValue NS_AVAILABLE(10_5, 2_0); 
@property (readonly) NSUInteger unsignedIntegerValue NS_AVAILABLE(10_5, 2_0);

// 这个灰常好用！
@property (readonly, copy) NSString *stringValue;

• 排序

    NSNumber *number1 = [NSNumber numberWithInteger:13];
    NSNumber *number2 = [NSNumber numberWithInteger:14];
    
    NSComparisonResult result = [number1 compare:number2];
    
    if (result == NSOrderedAscending) {
        NSLog(@"升序");//number2 比 number1 大
    }else if (result == NSOrderedSame){
        NSLog(@"一致");
    }else if (result == NSOrderedDescending){
        NSLog(@"降序");
    }else{
        NSLog(@"error");
    }

• 判断是否一致

    NSNumber *number1 = [NSNumber numberWithInteger:13];
    NSNumber *number2 = [NSNumber numberWithInteger:14];
    
    if ([number1 isEqualToNumber:number2]) {
        NSLog(@"same");
    }else{
        NSLog(@"nonono");
    }

• 本地化的字符串，规范化。继续研究 NSLocale

    NSNumber *number2 = [NSNumber numberWithInteger:1314];
    NSString *string = [number2 descriptionWithLocale:[NSLocale currentLocale]];
    
    NSLog(@"%@",string);

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