iOS雷达效果
这段时间新app开始了，有个产品需求是做一个类似如下效果的雷达图：
中间的图片是用户头像，然后需要展示一个雷达扫描的效果。
分析下雷达图的大致构成：
底部一个呈现用户头像的UIImageView 几个颜色渐变的同心圆，这些同心圆。 只需要在雷达视图的drawRect方法里画就可以了 盖在最上层的一个扇形，且扇形的圆心和雷达图视图的圆心是同一个点。扫描效果就是让这个扇形绕圆心转，因此把这个扇形抽成一个单独的类比较好。
同时这个雷达图应该提供两个接口：开始动画，暂停动画。因此雷达图的.h文件暴露出来的接口如下：
@interface CPRadarView : UIView - (void)start;//开始扫描 - (void)stop;//停止扫描 @end
.m文件实现如下：
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; } }
其中CPSectorView 是定义的扇形视图，它什么都没干，只是将这个扇形画出来，其.h文件如下：
@interface CPSectorView : UIView - (instancetype)initWithRadius:(CGFloat)radius degree:(CGFloat)degree; @end
radius 表示扇形的半径，degree表示扇形的弧度。其m文件如下：
@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 }
如果对扇形不做径向颜色渐变直接用注释的代码即可。具体代码就不解释了，注释和函数名字都很清晰。
以上就是对IOS 雷达效果的资料整理，后续继续补充相关资料，谢谢大家对本站的支持！
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