NSValue/NSNumber

本文详细介绍了Objective-C与Swift中如何将基本数据类型如int、float、double、char封装成对象,以及如何通过NSValue类实现CGPoint、CGSize、CGRect、NSRange、NSEdgeInsets的封装;同时阐述了如何将对象转换回基本数据类型。此外,还深入讲解了OC中字符串的强大功能,包括初始化、操作和拼接字符串的方法。

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Foundation框架下的基本类

NSValue/NSNumber

功能

将OC和C语言当中的基本数据类型转换成实例对象,即将值类型转换成引用类型

OC和C中的基本数据类型
        int a = 5;
        float b = 4.5;
        double c = 34.5545;
        char d = 'c';
//        CGPoint point = {3,5};
//        CGSize size = {30,47};
//        CGRect rect = {point,size};
        CGPoint point = CGPointMake(3, 5);
        CGSize size = CGSizeMake(40, 60);
        CGRect rect = CGRectMake(3, 5, 40, 60);
        NSRange range = NSMakeRange(3, 7);
        NSEdgeInsets edgeInsets = NSEdgeInsetsMake(10, 10, 10, 10);

NSValue 为 NSNumber 的父类.
其中NSValue类可以将CGPointCGSizeCGRectNSRangeNSEdgeInsets转换成对象

 NSValue *pointValue = [NSValue valueWithPoint:point];
        NSValue *sizeValue = [NSValue valueWithSize:size];
        NSValue *rectValue = [NSValue valueWithRect:rect];
        NSValue *rangeValue = [NSValue valueWithRange:range];
        NSValue *edgeInsetsValue = [NSValue valueWithEdgeInsets:edgeInsets];

其中NSNumber类可以将intfloatdoublecharBOOL等C中基本数据类型转换成对象

NSNumber *intNumber = [NSNumber numberWithInt:1];
        NSNumber *integerNumber = [NSNumber numberWithInteger:12];
        NSNumber *floatNumber = [NSNumber numberWithFloat:12.3];
        NSNumber *doubleNumber = [NSNumber numberWithDouble:12.455];
        NSNumber *charNumber = [NSNumber numberWithChar:'a'];
        NSNumber *boolNumber = [NSNumber numberWithBool:YES];

我们将C和OC中的基本数据类型(值类型)转换成对象(引用类型)的过程,叫做封装。相对应的,也有一个将对象转变成基本数据类型,此过程叫做拆包。

//拆包
CGPoint point1 = [pointValue pointValue];
        CGSize size1 = [sizeValue sizeValue];
        CGRect rect1 = [rectValue rectValue];
        NSRange range1 = [rangeValue rangeValue];
        NSEdgeInsets edgeInsets1 = [edgeInsetsValue edgeInsetsValue];
        int a1 = [intNumber intValue];
        NSInteger a2 = [integerNumber integerValue];
        float a3 = [floatNumber floatValue];
        double a4 = [doubleNumber doubleValue];
        char a5 = [charNumber charValue];
        BOOL a6 = [boolNumber boolValue]

NSString / NSMutableString

OC中的字符串具有强大的功能,即封装性极强,我们只需要找到对应API,就可以对字符串做相应操作。OC中字符串分为 `不可变字符串` 和 `可变字符串`,其中`可变字符串`是`不可变字符串`的子类.
在iOS开发中,字符串通常用作显示文本,即作为`UILabel`、`UITextFeild`等一些`UIKit`框架下控件的显示文本
NSString 不可变字符串
初始化字符串

1.快速初始化

NSString *string1 = @"bokanwisdom";

2.格式化的方式初始化字符串

NSString *string4 = [NSString stringWithFormat:@"%d%f%@",3,3.14,@"dajiahao"];

note:对于用格式化方式来构造字符串实例来讲,其作用并不是仅仅来构造一个字符串对象,它还可以用来做字符串拼接

3.从本地文件中读取字符串

NSString *string7 = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:&error];

NSString *string8 = [NSString stringWithContentsOfFile:path usedEncoding:&encoding error:&error];

4.从网络中读取一个字符串


NSURL *url = [NSURL URLWithString:@"http://www.baidu.com"];
NSString *string9 = [NSString stringWithContentsOfURL:url encoding:4 error:&error];
字符串的操作

1.字符串长度

NSUInteger length = string10.length;

2.字符串的截取

       NSString *subStr1 = [string10 substringToIndex:8];


       NSString *subStr2 = [string10 substringFromIndex:8];


        NSString *subStr3 = [string10 substringWithRange:NSMakeRange(8, length-8)];

3.字符串比较

==:表示两个字符串内容和指针都相同

 if (subStr2 == subStr3) {
            //内容和指针都相等时,才成立
            NSLog(@"subStr2和subStr3相等");
        }else{
            NSLog(@"subStr2和subStr3不相等");
        }

[subStr2 isEqualToString:subStr3]:表示两个字符串内容是否相同

  if ([subStr2 isEqualToString:subStr3]) {
            NSLog(@"subStr2和subStr3内容相同");

        }else{
            NSLog(@"subStr2和subStr3内容不相同");
        }
  1. 根据字符串拿到对应的range

NSRange range = [string10 rangeOfString:@"人家"];

5.判断字符串中是否有xx前缀或xx后缀

        NSString *string11 = @"www.baidu.com";
        if ([string11 hasPrefix:@"http://"]) {
            NSLog(@"含有此前缀");
        }else{
            NSLog(@"不含有此前缀");
        }
        NSString *string12 = @"sdfdf.jpg";
        if([string12 hasSuffix:@".jpg"]||[string12 hasSuffix:@".png"]){
            NSLog(@"含有此后缀");
        }

6.字符串拼接

 NSString *string13 = [@"http://" stringByAppendingString:string11];
        NSLog(@"string13 = %@",string13);

        NSString *domainStr = @"http://baidu.com";

        NSString *xxx = @"login";

        //http://baidu.com/login
       NSString *string14 = [NSString stringWithFormat:@"%@/%@",domainStr,xxx];
        NSLog(@"string14 = %@",string14);

        NSString *string15 = [domainStr stringByAppendingPathComponent:xxx];
        NSLog(@"string15 = %@",string15);
        //http://b.hiphotos.baidu.com/image/pic/item/e4dde71190ef76c666af095f9e16fdfaaf516741.jpg
        NSString *imgPath = @"http://b.hiphotos.baidu.com/image/pic/item/e4dde71190ef76c666af095f9e16fdfaaf516741.jpg";

        imgPath = [imgPath lastPathComponent];
        NSLog(@"imgPath = %@",imgPath);

        path = [path lastPathComponent];
        NSLog(@"path = %@",path);


        NSString *theImageName = @"lishucheng";
       theImageName = [theImageName stringByAppendingPathExtension:@"png"];
        NSLog(@"theImageName = %@",theImageName);
为下列代码实现可暂停效果: import UIKit class ViewController: UIViewController { private let radarAnimation = "radarAnimation" private var animationLayer: CALayer? private var animationGroup: CAAnimationGroup? private var opBtn: UIButton! override func viewDidLoad() { super.viewDidLoad() let first = makeRadarAnimation(showRect: CGRect(x: 120, y: 100, width: 100, height: 100), isRound: true) view.layer.addSublayer(first) opBtn = UIButton(frame: CGRect(x: 100, y: 450, width: 80, height: 80)) opBtn.backgroundColor = UIColor.red opBtn.clipsToBounds = true opBtn.setTitle("Hsu", for: .normal) opBtn.layer.cornerRadius = 10 view.addSubview(opBtn) let second = makeRadarAnimation(showRect: opBtn.frame, isRound: false) view.layer.insertSublayer(second, below: opBtn.layer) } @IBAction func startAction(_ sender: UIButton) { animationLayer?.add(animationGroup!, forKey: radarAnimation) } @IBAction func stopAction(_ sender: UIButton) { animationLayer?.removeAnimation(forKey: radarAnimation) } private func makeRadarAnimation(showRect: CGRect, isRound: Bool) -> CALayer { // 1. 一个动态波 let shapeLayer = CAShapeLayer() shapeLayer.frame = showRect // showRect 最大内切圆 if isRound { shapeLayer.path = UIBezierPath(ovalIn: CGRect(x: 0, y: 0, width: showRect.width, height: showRect.height)).cgPath } else { // 矩形 shapeLayer.path = UIBezierPath(roundedRect: CGRect(x: 0, y: 0, width: showRect.width, height: showRect.height), cornerRadius: 10).cgPath } shapeLayer.fillColor = UIColor.orange.cgColor // 默认初始颜色透明度 shapeLayer.opacity = 0.0 animationLayer = shapeLayer // 2. 需要重复的动态波,即创建副本 let replicator = CAReplicatorLayer() replicator.frame = shapeLayer.bounds replicator.instanceCount = 4 replicator.instanceDelay = 1.0 replicator.addSublayer(shapeLayer) // 3. 创建动画组 let opacityAnimation = CABasicAnimation(keyPath: "opacity") opacityAnimation.fromValue = NSNumber(floatLiteral: 1.0) // 开始透明度 opacityAnimation.toValue = NSNumber(floatLiteral: 0) // 结束时透明底 let scaleAnimation = CABasicAnimation(keyPath: "transform") if isRound { scaleAnimation.fromValue = NSValue.init(caTransform3D: CATransform3DScale(CATransform3DIdentity, 0, 0, 0)) // 缩放起始大小 } else { scaleAnimation.fromValue = NSValue.init(caTransform3D: CATransform3DScale(CATransform3DIdentity, 1.0, 1.0, 0)) // 缩放起始大小 } scaleAnimation.toValue = NSValue.init(caTransform3D: CATransform3DScale(CATransform3DIdentity, 1.5, 1.5, 0)) // 缩放结束大小 let animationGroup = CAAnimationGroup() animationGroup.animations = [opacityAnimation, scaleAnimation] animationGroup.duration = 3.0 // 动画执行时间 animationGroup.repeatCount = HUGE // 最大重复 animationGroup.autoreverses = false self.animationGroup = animationGroup shapeLayer.add(animationGroup, forKey: radarAnimation) return replicator } }
06-03
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