iOS实现雷达扫描效果

本文实例为大家分享了ios实现雷达扫描的具体代码，供大家参考，具体内容如下

#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;
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。