iOS 雷达效果实例详解

@interface CPRadarView : UIView- (void)start;//开始扫描- (void)stop;//停止扫描@end

typedef NS_ENUM(NSUInteger, SectorAnimationStatus) {//扇形视图动画状态 SectorAnimationUnStart, SectorAnimationIsRunning, SectorAnimationIsPaused,};#define CircleGap 15@interface CPRadarView ()@property (nonatomic, strong) CPSectorView sectorView;   //扇形视图@property (nonatomic, assign) SectorAnimationStatus status;@end@implementation CPRadarView- (instancetype)initWithFrame:(CGRect)frame { if(self = [super initWithFrame:frame]) {  [self setupUI];  _status = SectorAnimationUnStart; } return self;}- (void)setupUI { self.backgroundColor = [UIColor whiteColor]; [self addSubview:({  CGRect temp = self.frame;  UIImageView imageView = [[UIImageView alloc] initWithFrame:CGRectMake((temp.size.width - temp.size.width / 3.0) / 2.0, (temp.size.height - temp.size.width / 3.0) / 2.0, temp.size.width / 3.0, temp.size.width / 3.0)];  imageView.layer.cornerRadius = temp.size.width / 6.0;  imageView.layer.masksToBounds = YES;  imageView.image = [UIImage imageNamed:@"hehe.JPG"];  imageView; })]; [self addSubview:({   CGRect temp = self.frame;  _sectorView = [[CPSectorView alloc] initWithRadius:temp.size.width / 6.0 + 4 CircleGap degree:M_PI / 6];  CGRect frame = _sectorView.frame;  frame.origin.x = (self.frame.size.width - frame.size.width) / 2.0;  frame.origin.y = (self.frame.size.height - frame.size.height) / 2.0;  _sectorView.frame = frame;  _sectorView; })];}- (void)start { if (_status == SectorAnimationUnStart) {  _status = SectorAnimationIsRunning;  CABasicAnimation rotationAnimation;  rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];  rotationAnimation.toValue = [NSNumber numberWithFloat: 2 M_PI ];  rotationAnimation.duration = 5;  rotationAnimation.cumulative = YES;  rotationAnimation.removedOnCompletion = NO;  rotationAnimation.repeatCount = MAXFLOAT;  rotationAnimation.fillMode = kCAFillModeForwards;  [_sectorView.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"]; } if (_status == SectorAnimationIsPaused) {  _status = SectorAnimationIsRunning;  [self resumeLayer:_sectorView.layer]; }}- (void)stop { _status = SectorAnimationIsPaused; [self pauseLayer:_sectorView.layer];}/* 暂停动画  @param layer layer /-(void)pauseLayer:(CALayer)layer { CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil]; layer.speed = 0.0; layer.timeOffset = pausedTime;}/* 恢复动画  @param layer layer /- (void)resumeLayer:(CALayer)layer { CFTimeInterval pausedTime = [layer timeOffset]; layer.speed = 1.0; layer.timeOffset = 0.0; layer.beginTime = 0.0; CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime; layer.beginTime = timeSincePause;}/* 主要是用于画同心圆  @param rect rect /- (void)drawRect:(CGRect)rect { CGContextRef context = UIGraphicsGetCurrentContext(); NSArray colors = @[[UIColor colorWithHexString:@"ff4e7d"], [UIColor colorWithHexString:@"fd7293"], [UIColor colorWithHexString:@"fcb8cd"], [UIColor colorWithHexString:@"fde9f2"], [UIColor colorWithHexString:@"fcebf3"]]; CGFloat radius = rect.size.width / 6.0; for (UIColor color in colors) {  CGFloat red, green, blue, alpha;  [color getRed:&red green:&green blue:&blue alpha:&alpha];  CGContextSetRGBStrokeColor(context, red, green, blue, alpha);  CGContextSetLineWidth(context, 1);  CGContextAddArc(context, rect.size.width / 2.0, rect.size.height / 2.0, radius, 0, 2* M_PI, 0);   CGContextDrawPath(context, kCGPathStroke);  radius += CircleGap; }}

@interface CPSectorView : UIView- (instancetype)initWithRadius:(CGFloat)radius degree:(CGFloat)degree;@end

@interface CPSectorView ()@property (nonatomic, assign) CGFloat radius;@property (nonatomic, assign) CGFloat degree;@end@implementation CPSectorView- (instancetype)initWithRadius:(CGFloat )radius degree:(CGFloat)degree { self = [super initWithFrame:CGRectMake(0, 0, 2 radius, 2 radius)]; if (self) {  _degree = degree;  _radius = radius; } self.backgroundColor = [UIColor clearColor]; return self;}- (void)drawRect:(CGRect)rect {// CGContextRef context = UIGraphicsGetCurrentContext();// UIColor *aColor = [UIColor colorWithHexString:@"ff4e7d" alpha:0.5];// CGContextSetRGBStrokeColor(context, 1, 1, 1, 0);// CGPoint center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));// CGContextSetFillColorWithColor(context, aColor.CGColor);//填充颜色//// CGContextMoveToPoint(context, center.x, center.y);// CGContextAddArc(context,center.x, center.y, _radius, _degree / 2.0, -_degree / 2.0, 1);// CGContextClosePath(context);// CGContextDrawPath(context, kCGPathFillStroke); //绘制路径 CGContextRef ctx = UIGraphicsGetCurrentContext(); UIGraphicsBeginImageContext(rect.size); CGContextRef imgCtx = UIGraphicsGetCurrentContext(); CGPoint center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect)); CGContextMoveToPoint(imgCtx, center.x,center.y); CGContextSetFillColor(imgCtx, CGColorGetComponents([UIColor blackColor].CGColor)); CGContextAddArc(imgCtx, center.x, center.y, _radius, _degree / 2.0, -_degree / 2.0, 1); CGContextFillPath(imgCtx);//画扇形遮罩 CGImageRef mask = CGBitmapContextCreateImage(UIGraphicsGetCurrentContext()); UIGraphicsEndImageContext(); CGContextClipToMask(ctx, self.bounds, mask); CGFloat components[8]={  1.0, 0.306, 0.49, 0.5,  //start color(r,g,b,alpha)  0.992, 0.937, 0.890, 0.5  //end color }; //为扇形增加径向渐变色 CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB(); CGGradientRef gradient = CGGradientCreateWithColorComponents(space, components, NULL,2); CGColorSpaceRelease(space),space=NULL;//release CGPoint start = center; CGPoint end = center; CGFloat startRadius = 0.0f; CGFloat endRadius = _radius; CGContextRef graCtx = UIGraphicsGetCurrentContext(); CGContextDrawRadialGradient(graCtx, gradient, start, startRadius, end, endRadius, 0); CGGradientRelease(gradient),gradient=NULL;//release}