#import <UIKit/UIKit.h>@interface LTIndicatiorView : UIView@PRoperty(nonatomic,strong)UIColor *color;@property(nonatomic,assign)float repeatCount;@property(nonatomic,strong)UIColor *borderColor;@property(nonatomic,assign)float borderWidth;@end@interface LTRadarView : UIView@property(nonatomic,strong)UIColor *color;@property(nonatomic,strong)UIColor *borderColor;@property(nonatomic,assign)float borderWidth;@property(nonatomic,assign)int pulsingCount;@property(nonatomic,assign)float duration;@property(nonatomic,assign)float repeatCount;@property(nonatomic,strong)CALayer *pulsingLayer;@end
.m文件
////  LTRadarView.m//  raderScan////  Created by mac on 17/2/5.//  Copyright © 2017年 mac. All rights reserved.//#import "LTRadarView.h"#define Angel 15@interface LTRadarButton : UIButton@end@implementation LTRadarButton- (void)removeFromSuperview{    [UIView beginAnimations:@"" context:nil];    [UIView setAnimationDuration:0.5];    self.transform = CGAffineTransformMakeScale(0.2, 0.2);    self.alpha = 0;    [UIView setAnimationDidStopSelector:@selector(callSuperRemoveFromSuperview)];    [UIView commitAnimations];}- (void)callSuperRemoveFromSuperview{    [super removeFromSuperview];}- (id)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    self.alpha = 0;    return self;}- (void)didMoveToWindow{    [super didMoveToWindow];     self.transform = CGAffineTransformMakeScale(0.2, 0.2);    if (self.window) {        [UIView animateWithDuration:0.5 animations:^{            self.transform = CGAffineTransformIdentity;            self.alpha = 1;        }];    }    }@end@implementation LTIndicatiorView- (id)initWithFrame:(CGRect)frame{    if (self = [super initWithFrame:frame]) {        _color = [UIColor greenColor];        _repeatCount = HUGE_VALF;        _borderColor = [UIColor redColor];        _borderWidth = 1.0f;    }    return self;} // Only override drawRect: if you perform custom drawing. // An empty implementation adversely affects performance during animation. - (void)drawRect:(CGRect)rect { // Drawing code          self.backgroundColor = [UIColor whiteColor];     [super drawRect:rect];     self.layer.cornerRadius = self.frame.size.height/2.0f;     self.clipsToBounds = YES;     self.layer.borderColor = [UIColor clearColor].CGColor;     self.layer.borderWidth = 50;     self.layer.masksToBounds = YES;               CGContextRef context = UIGraphicsGetCurrentContext();     for (int i = 0; i < Angel; i++) {         CGFloat alpha = (float)i /(float)600;         CGColorRef shadowColor = [[UIColor greenColor] colorWithAlphaComponent:alpha].CGColor;//計算扇形填充顏色         CGContextSetFillColorWithColor(context, shadowColor);         CGContextMoveToPoint(context, self.center.x, self.center.y);//指定員心         CGFloat startAngle =  (-Angel+i+1.15)/Angel*(float)M_PI;         CGFloat endAngle = (-Angel+i-1.15)/Angel*(float)M_PI;//         NSLog(@"startAngle = %f endAngle = %f ,alpha = %f",startAngle,endAngle,alpha);         CGContextAddArc(context, self.center.x, self.center.y, self.frame.size.height/2.0f,0, 25, 1);//畫一個扇形         CGContextClosePath(context);                  CGContextDrawPath(context, kCGPathFill);//繪制扇形     }          CGContextSetLineWidth(context, 1);//掃描線寬度     CGContextSetStrokeColorWithColor(context, [_color colorWithAlphaComponent:1].CGColor);//掃描線顏色     CGContextMoveToPoint(context, self.center.x, self.center.y);     CGContextAddLineToPoint(context, self.frame.size.height, self.center.y);     CGContextStrokePath(context);          CGContextSetRGBStrokeColor(context,255/255.0, 255/255.0, 255/255.0, 0.1);//最外面圓顏色     CGContextSetLineWidth(context, 10);//線寬度     CGContextAddArc(context, self.center.x, self.center.y, self.frame.size.height/2.0, 0, 2*M_PI, 1);//添加一個圓     CGContextDrawPath(context, kCGPathStroke);//繪制路徑          CGContextStrokePath(context);//顯示繪制               //掃描動畫     CABasicAnimation *rotateAnimation = [CABasicAnimation animation];     rotateAnimation.keyPath = @"transform.rotation.z";     rotateAnimation.toValue = @(2*M_PI);     rotateAnimation.duration = 3;     rotateAnimation.removedOnCompletion = NO;     rotateAnimation.repeatCount = _repeatCount;         [self.layer addAnimation:rotateAnimation forKey:@"rotate_layer"]; }@end@implementation LTRadarView{    NSMutableArray *items;}- (id)initWithFrame:(CGRect)frame{    if (self = [super initWithFrame:frame]) {                items = [NSMutableArray array];        _color = [UIColor redColor];              _borderColor = [UIColor greenColor];        _pulsingCount = 3;        _duration = 3;        _repeatCount = HUGE_VALF;        _borderWidth = 3.0f;    }    return self;}// Only override drawRect: if you perform custom drawing.// An empty implementation adversely affects performance during animation.- (void)drawRect:(CGRect)rect {    // Drawing code    [super drawRect:rect];        self.layer.cornerRadius = self.frame.size.height/2;    self.clipsToBounds = YES;    self.layer.borderColor = [UIColor clearColor].CGColor;    self.layer.borderColor = [UIColor clearColor].CGColor;    self.layer.borderWidth = 50;    self.layer.masksToBounds = YES;        CGContextRef ctx = UIGraphicsGetCurrentContext();    CGContextSetRGBFillColor(ctx, 0/255.0, 0/255.0, 0/255.0, 1);//圓顏色    CGContextSetLineWidth(ctx, 1);//寬度    CGContextAddArc(ctx, self.center.x, self.center.y, self.frame.size.height/2, 0, 2*M_PI, 1);//添加一個圓    CGContextDrawPath(ctx, kCGPathStroke);//繪制    CGContextStrokePath(ctx);//顯示        CALayer *animationLayer = [CALayer layer];    animationLayer.frame = self.layer.frame;    for (int i = 0; i < _pulsingCount; i++) {                CALayer *pulsingLayer = [CALayer layer];        pulsingLayer.frame = CGRectMake(0, 0, rect.size.width, rect.size.height);        pulsingLayer.borderColor = [UIColor clearColor].CGColor;        pulsingLayer.borderWidth = 1;        pulsingLayer.cornerRadius = rect.size.height/2;        pulsingLayer.backgroundColor = [UIColor redColor].CGColor;                CAAnimationGroup *animationGroup = [CAAnimationGroup animation];        animationGroup.fillMode = kCAFillModeBoth;        animationGroup.beginTime = CACurrentMediaTime() + (float) i * _duration / _pulsingCount;        animationGroup.duration = _duration;        animationGroup.repeatCount = HUGE_VALF;        animationGroup.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];        animationGroup.autoreverses = NO;        animationGroup.delegate = self;        animationGroup.removedOnCompletion = NO;                CABasicAnimation *scaleAnimation = [CABasicAnimation animation];        scaleAnimation.keyPath = @"transform.scale";        scaleAnimation.removedOnCompletion = NO;        scaleAnimation.fromValue = @(0.0f);        scaleAnimation.toValue = @1.0f;        scaleAnimation.autoreverses = NO;                        CAKeyframeAnimation *opacityAnimation = [CAKeyframeAnimation animation];        opacityAnimation.keyPath = @"opacity";        opacityAnimation.values = @[@1.0,@0.75,@0.5,@0.25,@0.0];        opacityAnimation.keyTimes = @[@0.0,@0.25,@0.5,@0.75,@1];        opacityAnimation.autoreverses = NO;        opacityAnimation.removedOnCompletion = NO;                animationGroup.animations = @[scaleAnimation,opacityAnimation];        [pulsingLayer addAnimation:animationGroup forKey:@"pulsing"];                [animationLayer addSublayer:pulsingLayer];    }        [self.layer addSublayer:animationLayer];        [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(addOrReplaceItem) userInfo:nil repeats:YES];}- (void)animation:(CALayer *)layer{    CAAnimationGroup *animationGroup = [CAAnimationGroup animation];    animationGroup.fillMode = kCAFillModeBoth;    animationGroup.beginTime = CACurrentMediaTime() + 1 * _duration / _pulsingCount;    animationGroup.duration = _duration;    animationGroup.repeatCount = HUGE_VALF;    animationGroup.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];    animationGroup.autoreverses = NO;    animationGroup.delegate = self;    animationGroup.removedOnCompletion = NO;        CABasicAnimation *scaleAnimation = [CABasicAnimation animation];    scaleAnimation.keyPath = @"transform.scale";    scaleAnimation.removedOnCompletion = NO;    scaleAnimation.fromValue = @(0.0f);    scaleAnimation.toValue = @1.0f;    scaleAnimation.autoreverses = NO;            CAKeyframeAnimation *opacityAnimation = [CAKeyframeAnimation animation];    opacityAnimation.keyPath = @"opacity";    opacityAnimation.values = @[@1.0,@0.75,@0.5,@0.25,@0.0];    opacityAnimation.keyTimes = @[@0.0,@0.25,@0.5,@0.75,@1];    opacityAnimation.autoreverses = NO;    opacityAnimation.removedOnCompletion = NO;        animationGroup.animations = @[scaleAnimation,opacityAnimation];    [layer addAnimation:animationGroup forKey:@"pulsing"];        }#define RandomColor [UIColor colorWithRed:arc4random_uniform(256)/255.0 green:arc4random_uniform(256)/255.0 blue:arc4random_uniform(256)/255.0 alpha:1.0]/* 生成一個在圓里面的坐標(biāo) 生成的坐標(biāo)要圍繞中心的綠點（圓心），讓我們重新翻開數(shù)學(xué)課本，看看高中數(shù)學(xué)對三角函數(shù)的定義： 在一個平面直角坐標(biāo)系中，以原點為圓心，1 為半徑畫一個圓，這個圓交 x 軸于 A 點。以 O 為旋轉(zhuǎn)中心，將 A 點逆時針旋轉(zhuǎn)一定的角度α至 B 點，設(shè)此時 B 點的坐標(biāo)是(x,y)，那么此時 y 的值就叫做α的正弦，記作 sinα；此時 x 的值就叫做α的余弦，記作 cosα；y 與 x 的比值 y/x 就叫做α的正切，記作 tanα。  任意角三角函數(shù) 正弦sinθ=y/r, 余弦cosθ=x/r,正切tanθ=y/x,余切cotθ=x/y,正割secθ=r/x,余割cscθ=r/y 銳角三角函數(shù) 正弦sinA=a/c, 余弦cosA=b/c,正切tanA=a/b,余切cotA=b/a,正割secA=c/b,余割cscA=c/a  還有一個很重要的公式：圓的參數(shù)方程：以點O（a，b）為圓心，以r為半徑的圓的參數(shù)方程是 x=a+r*cosθ, y=b+r*sinθ, （其中θ為參數(shù)） 到這里為止，思路就清晰了，以下是generateCenterPointInRadar的方法實現(xiàn)： */- (CGPoint)generateCenterPointInRadar{    float  angle = arc4random() % 360;//隨機(jī)一個角度    float radius = arc4random() % (int)((self.bounds.size.width - 44)/2);//隨機(jī)一個半徑， 這里減去44是因為要把這個view顯示在圓里面，如果不減44，則有可能會顯示在圓外面    double x = cos(angle) * radius;//計算隨機(jī)出現(xiàn)的一個角度的x坐標(biāo) x=a+r*cosθ r = radius, θ = angle ,a ＝ 圓心的x坐標(biāo)    double y = sin(angle) * radius;//計算隨機(jī)出現(xiàn)的一個角度的y坐標(biāo) y=b+r*sinθ r = radius, θ = angle ,b ＝ 圓心的y坐標(biāo)    return CGPointMake(x + self.bounds.size.width / 2, y + self.bounds.size.height / 2);//x y 分別加個圓心的坐標(biāo)即self.center.x.y}- (void)addOrReplaceItem{    int maxCount = 10;        LTRadarButton *radarButton = [LTRadarButton buttonWithType:UIButtonTypeCustom];    radarButton.frame = CGRectMake(0, 0, 44, 44);    radarButton.backgroundColor = RandomColor;    radarButton.layer.cornerRadius = 44/2;        do {        CGPoint center = [self generateCenterPointInRadar];        radarButton.center = CGPointMake(center.x, center.y);    } while ([self itemFrameIntersectsInOtherItem:radarButton.frame]);            [self addSubview:radarButton];    [items addObject:radarButton];        if (items.count > maxCount)    {        UIView * view = [items firstObject];        [view removeFromSuperview];        [items removeObject:view];    }}/* 我們現(xiàn)在在生成每個item的center的時候，沒有和已有的item進(jìn)行比較，這是一個比較耗性能的操作，如果你的itemSize過大，maxCount過多，這甚至能導(dǎo)致死循環(huán)，如果是那樣的話，你可能在對itemSize以及maxCount做出限制的同時，也對循環(huán)的數(shù)量也進(jìn)行控制，如果在生成一個item的center的時候，進(jìn)行了過多的循環(huán)，就可以視為進(jìn)入死循環(huán)了，在這種情況下，你只能重新計算已有的centers。這里不考慮這種極端情況，因為目前的itemSize和maxCount的配合，不會出現(xiàn)死循環(huán)。 我們添加一個itemFrameIntersectsInOtherItem私有方法來判斷是否和之前生成的center有了重疊： */- (BOOL)itemFrameIntersectsInOtherItem:(CGRect)frame{    for (UIView *item in items)    {        if (CGRectIntersectsRect(item.frame, frame))        {            return YES;        }    }    return NO;}@end