如何在當前位置旋轉CALayer？

Question

如何在當前位置旋轉CALayer？

Answer 1

我使用非常相似的代碼，它正在旋轉。

我將弧度賦值爲float並且缺少視圖的賦值以顯示圖層。

 
- (void)spinLayer:(CALayer*)layer { 

    // Create a new spinning animation 
    CAAnimation* spinningAnimation = [self animationForSpinning]; 

    // Assign this animation to the provided layer's opacity attribute. 
    // Any subsequent change to the layer's opacity will 
    // trigger the animation. 
    [layer addAnimation:spinningAnimation forKey:@"opacity"]; 

    // So let's trigger it now 
    layer.opacity = 0.99; 
[self.contentView.layer addSublayer:layer]; 
}