iphone - 如何在 Core Plot 中为条形图的外观设置动画？

Question

当第一次使用 Core Plot 显示条形图时，我希望条形向上增长，直到达到正确的高度。

您将如何使用此框架创建这样的动画？

Answer 1

这是我做的:

1. 在我的 viewDidLoad Controller 方法中，我创建了 CPTXYGraph:

   graph = [[CPTXYGraph alloc] initWithFrame:self.view.bounds];
   

2. 我为空图添加了动画:

   CAKeyframeAnimation *scale = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
   

3. 然后在 animationDidStop 委托(delegate)的方法中，我将绘图数据和动画添加到图中:

   CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform.scale.y"];
   [anim setDuration:2.0f];
   
   anim.toValue = [NSNumber numberWithFloat:1.0f];
   anim.fromValue = [NSNumber numberWithFloat:0.0f];
   anim.removedOnCompletion = NO;
   anim.delegate = self;
   anim.fillMode = kCAFillModeForwards;
   
   gPlot.anchorPoint = CGPointMake(0.0, 0.0);
   
   [gPlot addAnimation:anim forKey:@"grow"];
   
   [graph addPlot:gPlot ];// IMPORTANT here I added the plot data to the graph :) .