前言
這幾天一直跟開源的抖音demo斗智斗勇,今天跟大家分享的是抖音中或者快手中加載視頻的動畫,這個加載效果還是挺實用,下面話不多說了,來隨著小編一起學習學習吧
上圖看成品
實現原理
首先我創建一個視圖
@interface ViewController ()@property (nonatomic, strong) UIView *playLoadingView;@end@implementation ViewController- (void)viewDidLoad { [super viewDidLoad]; //init player status bar self.playLoadingView = [[UIView alloc]init]; self.playLoadingView.backgroundColor = [UIColor whiteColor]; [self.playLoadingView setHidden:YES]; [self.view addSubview:self.playLoadingView]; //make constraintes [self.playLoadingView mas_makeConstraints:^(MASConstraintMaker *make) { make.center.equalTo(self.view); make.width.mas_equalTo(1.0f); //寬 1 dp make.height.mas_equalTo(0.5f); //高 0.5 dp }]; [self startLoadingPlayAnimation:YES]; //調用動畫代碼}
這里我們可以看到 我們實際上創建的是一個 1pt寬度 0.5 pt的寬度 的視圖
緊接著動畫實現的代碼
- (void)startLoadingPlayAnimation:(BOOL)isStart { if (isStart) { self.playLoadingView.backgroundColor = [UIColor whiteColor]; self.playLoadingView.hidden = NO; [self.playLoadingView.layer removeAllAnimations]; CAAnimationGroup *animationGroup = [[CAAnimationGroup alloc] init]; animationGroup.duration = 0.5; animationGroup.beginTime = CACurrentMediaTime() + 0.5; animationGroup.repeatCount = MAXFLOAT; animationGroup.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; CABasicAnimation *scaleAnimation = [CABasicAnimation animation]; scaleAnimation.keyPath = @"transform.scale.x"; scaleAnimation.fromValue = @(1.0f); scaleAnimation.toValue = @(1.0f * ScreenWidth); CABasicAnimation *alphaAnimation = [CABasicAnimation animation]; alphaAnimation.keyPath = @"opacity"; alphaAnimation.fromValue = @(1.0f); alphaAnimation.toValue = @(0.5f); [animationGroup setAnimations:@[scaleAnimation, alphaAnimation]]; [self.playLoadingView.layer addAnimation:animationGroup forKey:nil]; } else { [self.playLoadingView.layer removeAllAnimations]; self.playLoadingView.hidden = YES; }}
完事 就這幾行代碼 搞定
其實核心的只有4行代碼
CABasicAnimation *scaleAnimation = [CABasicAnimation animation];scaleAnimation.keyPath = @"transform.scale.x";scaleAnimation.fromValue = @(1.0f);scaleAnimation.toValue = @(1.0f * ScreenWidth);
關鍵在scaleAnimation.keyPath = @"transform.scale.x";
這里我們要沿著x做縮放
縮放的得值從 1~屏幕寬度, 當然值多大自己可以控制.
如果@"transform.scale.y"
則是沿著Y軸縮放
當然 如果寫成@"transform.scale"
那就X,Y 一起縮放 大家可以試試.
總結
本篇的動畫技巧是 縮放的 transform.scale.y
從一個點 做layer縮放 就會出現 加載效果.
最后附上demo
好了,以上就是這篇文章的全部內容了,希望本文的內容對大家的學習或者工作具有一定的參考學習價值,如果有疑問大家可以留言交流,謝謝大家對VEVB武林網的支持。
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