動畫按鈕背景圖片

Question

我嘗試爲按鈕背景圖像創建動畫，但不知道我應該怎麼做才能獲得像這樣的gif一樣的結果。我需要從上到下做這個背景變化。謝謝你的幫助！

Answer 1

儘量做到這樣

CALayer *layer = [CALayer layer]; 
layer.frame = CGRectMake(0, self.view.bounds.size.height, self.view.bounds.size.width, self.view.bounds.size.height); 
layer.backgroundColor = [UIColor blueColor].CGColor; 
[self.view.layer addSublayer:layer]; 

CABasicAnimation *animation = [CABasicAnimation animation]; 
animation.keyPath = @"position.y"; 
animation.byValue = @(-self.view.bounds.size.height); 
animation.duration = 1; 

animation.fillMode = kCAFillModeForwards; 
animation.removedOnCompletion = NO; 
[layer addAnimation:animation forKey:@"Splash"];