iOS 圓的放大動畫效果

標籤：

第一步：建立一個View，將這個View添加到當前的控制器

如：

CGFloat timeW = self.view.bounds.size.width;timeAnimation * timean = [[timeAnimation alloc]initWithFrame:CGRectMake(0,0,timeW,timeW)];    　timean.center = CGPointMake(self.view.bounds.size.width*0.5, self.view.bounds.size.height *0.5);[self.view addSubview:timean];

第二步：在View的.m檔案中添加如下代碼

#define PI 3.14159265358979323846

#define kradius self.bounds.size.width*0.1

-(instancetype)initWithFrame:(CGRect)frame{    if (self = [super initWithFrame:frame]) {        self.frame = frame;        self.backgroundColor = [UIColor clearColor];    }    return self;}- (void)drawRect:(CGRect)rect {    CGContextRef context = UIGraphicsGetCurrentContext();        [self greenRound:context];    self.alpha = 0.5;    [self test];}-(void)test{    // 2.建立縮放動畫對象    CABasicAnimation *scale = [CABasicAnimation animation];    scale.keyPath = @"transform.scale";    scale.fromValue =[NSNumber numberWithFloat:0.0];    scale.toValue =[NSNumber numberWithFloat:1.0];    CABasicAnimation *scale1 = [CABasicAnimation animation];    scale1.keyPath = @"opacity";    scale1.fromValue =[NSNumber numberWithFloat:1.0];    scale1.toValue =[NSNumber numberWithFloat:0.0];    // 4.將所有的動畫添加到動畫組中    CAAnimationGroup *group = [CAAnimationGroup animation];    group.animations = @[scale,scale1];    group.duration =.6;    group.repeatCount = HUGE_VALF;    group.removedOnCompletion = NO;    group.fillMode = kCAFillModeForwards;    [self.layer addAnimation:group forKey:nil];}/**畫綠色的圓*/-(void)greenRound:(CGContextRef)context{    CGContextSetRGBStrokeColor(context, 33/255.0, 177/255.0, 75/255.0, 1);//畫筆線的顏色    CGContextSetLineWidth(context, 4.0);//線的寬度    // x,y為圓點座標，radius半徑，startAngle為開始的弧度，endAngle為 結束的弧度，clockwise 0為順時針，1為逆時針。    CGContextAddArc(context, self.bounds.size.width *0.5,self.bounds.size.height*0.5,self.bounds.size.width*0.21, 0, 2*PI, 0); //添加一個圓    CGContextDrawPath(context, kCGPathStroke); //繪製路徑}

 

iOS 圓的放大動畫效果