效果图

加载.gif

instancetype

-(instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        [self creatCircleAnimation];
    }
    return self;
}

creatCircleAnimation

-(void)creatCircleAnimation
{
    self.backgroundColor = [UIColor colorWithWhite:0.8f alpha:0.5f];
    CGFloat x = self.frame.size.width * 0.5;
    CGFloat y = self.frame.size.height * 0.5;
    
    CAShapeLayer *cycleLayer = [CAShapeLayer layer];
    cycleLayer.lineCap = kCALineCapRound;
    cycleLayer.lineJoin = kCALineJoinRound;
    cycleLayer.lineWidth = 5.f;
    cycleLayer.fillColor = [UIColor clearColor].CGColor;
    cycleLayer.strokeColor = [UIColor orangeColor].CGColor;
    cycleLayer.strokeEnd = 0.f;
    cycleLayer.path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(x - kRadius, y - kRadius, kRadius * 2, kRadius * 2)].CGPath;
    [self.layer addSublayer:cycleLayer];
    
    CABasicAnimation *strokeStartAnimation = [CABasicAnimation animationWithKeyPath:@"strokeStart"];
    strokeStartAnimation.fromValue = @(-1);
    strokeStartAnimation.toValue = @(1);
    CABasicAnimation *strokeEndAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    strokeEndAnimation.fromValue = @(0);
    strokeEndAnimation.toValue = @(1.0);
    
    CAAnimationGroup *animationGroup = [CAAnimationGroup new];
    animationGroup.duration = 1.f;
    animationGroup.repeatCount = INFINITY;
    animationGroup.animations = @[strokeStartAnimation,strokeEndAnimation];
    animationGroup.removedOnCompletion = NO;
    [cycleLayer addAnimation:animationGroup forKey:@"animationGroup"];
    
    CALayer *testLayer = [CALayer layer];
    testLayer.backgroundColor = [UIColor clearColor].CGColor;
    testLayer.frame = self.bounds;
    [self.layer addSublayer:testLayer];
    [testLayer addSublayer:cycleLayer];
    
    // [self setAnchorPoint:CGPointMake(0.5, 0.5) forView:self];
    CABasicAnimation *animation = [CABasicAnimation animation];
    animation.keyPath = @"transform.rotation.z";
    animation.duration = 1.f;
    animation.fromValue = @(0);
    animation.toValue = @(2*M_PI);
    animation.repeatCount = INFINITY;
    animation.removedOnCompletion = NO; // 防止点击HOME键再进入的时候，动画停止
    [testLayer addAnimation:animation forKey:nil];
    
    // 添加label
    UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, kRadius * 2 - 20, 25)];
    label.text = @"正在加载···";
    label.textColor = [UIColor orangeColor];
    label.adjustsFontSizeToFitWidth = YES;
    label.center = CGPointMake(x, y);
    [self addSubview:label];
    
}

remove

-(void)removeSelf
{
    [UIView animateWithDuration:0.2f animations:^{
        self.alpha = 0.f;
    }completion:^(BOOL finished) {
        [self removeFromSuperview];
    }];
}

使用

LoadingView *loading = [[LoadingView alloc]initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
[self.view addSubview:loading];