本篇内容介绍了“iOS实现雷达扫描效果的方法步骤”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
#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;//计算扇形填充颜色
CGContextSetFillColorWithColor(context, shadowColor);
CGContextMoveToPoint(context, self.center.x, self.center.y);//指定员心
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);//画一个扇形
CGContextClosePath(context);
CGContextDrawPath(context, kCGPathFill);//绘制扇形
}
CGContextSetLineWidth(context, 1);//扫描线宽度
CGContextSetStrokeColorWithColor(context, [_color colorWithAlphaComponent:1].CGColor);//扫描线颜色
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);//最外面圆颜色
CGContextSetLineWidth(context, 10);//线宽度
CGContextAddArc(context, self.center.x, self.center.y, self.frame.size.height/2.0, 0, 2*M_PI, 1);//添加一个圆
CGContextDrawPath(context, kCGPathStroke);//绘制路径
CGContextStrokePath(context);//显示绘制
//扫描动画
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);//圆颜色
CGContextSetLineWidth(ctx, 1);//宽度
CGContextAddArc(ctx, self.center.x, self.center.y, self.frame.size.height/2, 0, 2*M_PI, 1);//添加一个圆
CGContextDrawPath(ctx, kCGPathStroke);//绘制
CGContextStrokePath(ctx);//显示
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]
/*
生成一个在圆里面的坐标
生成的坐标要围绕中心的绿点（圆心），让我们重新翻开数学课本，看看高中数学对三角函数的定义：
在一个平面直角坐标系中，以原点为圆心，1 为半径画一个圆，这个圆交 x 轴于 A 点。以 O 为旋转中心，将 A 点逆时针旋转一定的角度α至 B 点，设此时 B 点的坐标是(x,y)，那么此时 y 的值就叫做α的正弦，记作 sinα；此时 x 的值就叫做α的余弦，记作 cosα；y 与 x 的比值 y/x 就叫做α的正切，记作 tanα。
任意角三角函数 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
锐角三角函数 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
还有一个很重要的公式：圆的参数方程：以点O（a，b）为圆心，以r为半径的圆的参数方程是 x=a+r*cosθ, y=b+r*sinθ, （其中θ为参数）
到这里为止，思路就清晰了，以下是generateCenterPointInRadar的方法实现：
*/
- (CGPoint)generateCenterPointInRadar
{
float angle = arc4random() % 360;//随机一个角度
float radius = arc4random() % (int)((self.bounds.size.width - 44)/2);//随机一个半径， 这里减去44是因为要把这个view显示在圆里面，如果不减44，则有可能会显示在圓外面
double x = cos(angle) * radius;//计算随机出现的一个角度的x坐标 x=a+r*cosθ r = radius, θ = angle ,a ＝ 圆心的x坐标
double y = sin(angle) * radius;//计算随机出现的一个角度的y坐标 y=b+r*sinθ r = radius, θ = angle ,b ＝ 圆心的y坐标
return CGPointMake(x + self.bounds.size.width / 2, y + self.bounds.size.height / 2);//x y 分别加个圆心的坐标即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];
}
}
/*
我们现在在生成每个item的center的时候，没有和已有的item进行比较，这是一个比较耗性能的操作，如果你的itemSize过大，maxCount过多，这甚至能导致死循环，如果是那样的话，你可能在对itemSize以及maxCount做出限制的同时，也对循环的数量也进行控制，如果在生成一个item的center的时候，进行了过多的循环，就可以视为进入死循环了，在这种情况下，你只能重新计算已有的centers。这里不考虑这种极端情况，因为目前的itemSize和maxCount的配合，不会出现死循环。
我们添加一个itemFrameIntersectsInOtherItem私有方法来判断是否和之前生成的center有了重叠：
*/
- (BOOL)itemFrameIntersectsInOtherItem:(CGRect)frame
{
for (UIView *item in items)
{
if (CGRectIntersectsRect(item.frame, frame))
{
return YES;
}
}
return NO;
}“iOS实现雷达扫描效果的方法步骤”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注亿速云网站，小编将为大家输出更多高质量的实用文章！
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