iOS 雷达效果实例详解

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：

1. 底部一个呈现用户头像的uiimageview
2. 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
3. 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！