FadeTo动画不起作用。的cocos2d

Question

根据这个代码节点必须慢慢出现，对吧？它不起作用。有什么问题？

   CCNodeColor *_backNode = [CCNodeColor nodeWithColor:[CCColor colorWithRed:0 green:0 blue:0    alpha:1.0f]];
    _backNode.opacity=0;
    [self addChild:_backNode z:5];
  [_backNode runAction:[CCActionFadeTo actionWithDuration:2 opacity:0.9]];

Answer 1

尝试使用alpha = 0并且不设置不透明度：

CCNodeColor *_backNode = [CCNodeColor nodeWithColor:[CCColor colorWithRed:0 
                                                                    green:0
                                                                     blue:0
                                                                    alpha:0.0f]];