iOS开发基础知识--碎片45

Person *p = [Person new];

// 调用对象p的test方法

[p performSelector:@selector(test)];

[person performSelector:@selector(test2:) withObject:@"传入参数"];

Person类代码：

#import "Person.h"
@implementation Person
- (void)test
{
    NSLog(@"无参数的对象方法");
}
- (void)test2:(NSString *)str
{
    NSLog(@"带有参数的方法%@",str);
}
@end

// 对一个数组array的每个元素执行一次test方法

[array makeObjectsPerformSelector:@selector(test)];

[array makeObjectsPerformSelector:@selector(test)  withObject:@"aaa"];
//对一个数组array进行排序

[array sortedArrayUsingSelector:@selector(compare:)];

#import <UIKit/UIKit.h>

@interface TapView : UIView
//目标
@property(weak,nonatomic)id target;
//行为
@property(assign,nonatomic)SEL action;

//自定义方法
-(void)addCustomtarget:(id)target andAction:(SEL)action;

@end

#import "TapView.h"

@implementation TapView

//自定义方法
-(void)addCustomtarget:(id)target andAction:(SEL)action{
    _action = action;
    _target = target;
}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //当视图点击的时候,target去执行action的方法并把自己传过去.
    //首先代理不能是空,而且代理(代理是对象!)的类中有方法并且能传出过来.
    if (nil != _target && [[_target class] instancesRespondToSelector:_action]) {
        [_target performSelector:_action withObject:self];
    }
}

#import <Foundation/Foundation.h>
#import <objc/runtime.h>
#import "Debug.h" // not given; just an assert

@interface NSObject (Extras)

// Enforce the rule that the selector used must return void.
- (void) performVoidReturnSelector:(SEL)aSelector withObject:(id)object;
- (void) performVoidReturnSelector:(SEL)aSelector;

@end

@implementation NSObject (Extras)

// Apparently the reason the regular performSelect gives a compile time warning is that the system doesn‘t know the return type. I‘m going to (a) make sure that the return type is void, and (b) disable this warning
// See http://stackoverflow.com/questions/7017281/performselector-may-cause-a-leak-because-its-selector-is-unknown

- (void) checkSelector:(SEL)aSelector {
    // See http://stackoverflow.com/questions/14602854/objective-c-is-there-a-way-to-check-a-selector-return-value
    Method m = class_getInstanceMethod([self class], aSelector);
    char type[128];
    method_getReturnType(m, type, sizeof(type));

    NSString *message = [[NSString alloc] initWithFormat:@"NSObject+Extras.performVoidReturnSelector: %@.%@ selector (type: %s)", [self class], NSStringFromSelector(aSelector), type];
    NSLog(@"%@", message);

    if (type[0] != ‘v‘) {
        message = [[NSString alloc] initWithFormat:@"%@ was not void", message];
        [Debug assertTrue:FALSE withMessage:message];
    }
}

- (void) performVoidReturnSelector:(SEL)aSelector withObject:(id)object {
    [self checkSelector:aSelector];

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
    // Since the selector (aSelector) is returning void, it doesn‘t make sense to try to obtain the return result of performSelector. In fact, if we do, it crashes the app.
    [self performSelector: aSelector withObject: object];
#pragma clang diagnostic pop    
}

- (void) performVoidReturnSelector:(SEL)aSelector {
    [self checkSelector:aSelector];

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
    [self performSelector: aSelector];
#pragma clang diagnostic pop
}

@end

#import <UIKit/UIKit.h>

@protocol TouchViewDelegate <NSObject>
-(void)changeViewColor:(UIColor *)color;
@end


@interface TouchView : UIView
//声明一个代理,这个代理遵守TouchViewDelegate协议,
@property(nonatomic,assign)id<TouchViewDelegate> delegate;
@end

#import "TouchView.h"

@implementation TouchView

//我们还是用touchesBegandian
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    if (nil != self.delegate && [self.delegate respondsToSelector:@selector(changeViewColor:)]) {
        //我们传一个颜色到我们的ViewController去.
        [self.delegate changeViewColor:[UIColor brownColor]];
    }
}

@end

运用代码：

#import "ViewController.h"
#import "TouchView.h"

//在这里ViewController 要遵守协议....
@interface ViewController ()<TouchViewDelegate>

@property(nonatomic,strong)TouchView *touchView;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    self.touchView = [[TouchView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];

    self.touchView.backgroundColor = [UIColor redColor];
    //指定touchView的代理为ViewController.即为本身~
    self.touchView.delegate =self;

    [self.view addSubview: self.touchView];
}

-(void)changeViewColor:(UIColor *)color{
    //现在参数color是有值的,这是因为在TouchView那个页面传过来的.
    self.touchView.backgroundColor = color;
}
@end

#import <UIKit/UIKit.h>

//给block改名成MyBlock
typedef void(^MyBlock)(NSString *);


@interface OtherViewController : UIViewController

//ARC:语义设置使用strong即可
@property(nonatomic,strong)MyBlock block;

@end

#import "OtherViewController.h"

@interface OtherViewController ()
@property(nonatomic,strong)UITextField *textField;
@end

@implementation OtherViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.textField = [[UITextField alloc]initWithFrame:CGRectMake(0, 100, 414, 40)];
    self.textField.backgroundColor = [UIColor lightGrayColor];
    self.view.backgroundColor = [UIColor whiteColor];
    [self.view addSubview: self.textField];
}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    self.block(_textField.text);
    [self.navigationController popViewControllerAnimated:YES];
}
@end

运用代码：

    OtherViewController *otherVC = [[OtherViewController alloc]init];
    __weak typeof(self)weak = self;
    //给block赋值~
    otherVC.block = ^(NSString *string){
        weak.label.text = string;
    };

    [self.navigationController pushViewController:otherVC animated:YES];

#pragma clang diagnostic push  
  
#pragma clang diagnostic ignored "-Wdeprecated-declarations"      
//会报警告的方法，比如SEL 
[TestFlight setDeviceIdentifier:[[UIDevice currentDevice] uniqueIdentifier]];  
  
#pragma clang diagnostic pop  

#pragma clang diagnostic push   
#pragma clang diagnostic ignored "-Wunused-variable"   
    
int a;   

#pragma clang diagnostic pop 

#import <UIKit/UIKit.h>
//六边形Button
@interface HexagonButton : UIView
NS_ASSUME_NONNULL_BEGIN

typedef void (^HexagonButtonBlock)();

@property (nonatomic, strong) UIBezierPath *path;
@property (nonatomic, strong) CAShapeLayer *maskLayer;
@property (nonatomic, strong) HexagonButtonBlock block; //点击事件

//添加点击事件


NS_ASSUME_NONNULL_END
@end

#import "HexagonButton.h"

@implementation HexagonButton
- (instancetype) initWithFrame:(CGRect)frame
{
    if ([super initWithFrame:frame]) {
        
        self.backgroundColor = [UIColor brownColor];
        self.userInteractionEnabled = YES;
        
        //添加单击手势
        UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(click:)];
        [self addGestureRecognizer:tap];
    }
    return self;
}
- (void) layoutSubviews
{
    [super layoutSubviews];
    CGFloat SIZE = self.frame.size.width;
    // step 1: 生成六边形路径
    CGFloat longSide = SIZE * 0.5 * cosf(M_PI * 30 / 180);
    CGFloat shortSide = SIZE * 0.5 * sin(M_PI * 30 / 180);
    CGFloat k = SIZE * 0.5 - longSide;  //路径整体下移，保证六边形路径位于图形中间
    
    _path = [UIBezierPath bezierPath];
    [_path moveToPoint:CGPointMake(0, longSide  + k)];
    [_path addLineToPoint:CGPointMake(shortSide, + k)];
    [_path addLineToPoint:CGPointMake(shortSide + shortSide + shortSide,  k)];
    [_path addLineToPoint:CGPointMake(SIZE, longSide + k)];
    [_path addLineToPoint:CGPointMake(shortSide * 3, longSide * 2 + k)];
    [_path addLineToPoint:CGPointMake(shortSide, longSide * 2 + k)];
    [_path closePath];
    
    // step 2: 根据路径生成蒙板
    _maskLayer = [CAShapeLayer layer];
    //    _maskLayer.position = self.center;
    _maskLayer.path = [_path CGPath];
    
    // step 3: 添加蒙版
    self.layer.mask = _maskLayer;

    self.backgroundColor = [UIColor orangeColor];
}

//点击事件
- (void) click:(UITapGestureRecognizer *) tap
{
    if (_block) {
        _block();
    }
}
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    //如果点击的区域在所创建的路径范围内
    if (CGPathContainsPoint(_path.CGPath, NULL, point, NO)) {
        return [super hitTest:point withEvent:event];
    }
    return nil;
}

@end

    //创建六变形按钮
    HexagonButton * hexagonButton = [[HexagonButton alloc] initWithFrame:CGRectMake(20, 20, 100, 100)];
    hexagonButton.center = self.view.center;
    hexagonButton.block = ^(){
        NSLog(@"六边形区域被点击");
    };
    [self.view addSubview:hexagonButton];

var controllerArr = self.navigationController?.viewControllers//获取Controller数组
controllerArr?.removeAll()//移除controllerArr中保存的历史路径
    //重新添加新的路径
controllerArr?.append(self.navigationController?.viewControllers[0])
controllerArr?.append(C)
controllerArr?.append(B)
    //这时历史路径为（root -> c -> b）
    //将组建好的新的跳转路径 set进self.navigationController里
self.navigationController?.setViewControllers(controllerArr!, animated: true)//直接写入，完成跳转B页面的同时修改了之前的跳转路径