ios - 集中中央标签栏按钮

Question

这是怎么做的？中央标签栏按钮的圆顶效果？它是圆顶图像在规则中心形状的标签按钮顶部的简单投影吗？或者还有什么？

Answer 1

您可以通过以下方式实现这一目标，

    UIButton* button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.frame = CGRectMake(0.0, 0.0, buttonImage.size.width, buttonImage.size.height);
    [button setBackgroundImage:buttonImage forState:UIControlStateNormal];
    [button setBackgroundImage:highlightImage forState:UIControlStateHighlighted];

    CGFloat heightDifference = buttonImage.size.height - self.tabBar.frame.size.height;
    if (heightDifference < 0)
      button.center = self.tabBar.center;
    else
    {
      CGPoint center = self.tabBar.center;
      center.y = center.y - heightDifference/2.0;
      button.center = center;
    }

    [self.view addSubview:button];

请检查这些链接：http: //idevrecipes.com/2010/12/16/raised-center-tab-bar-button/

您将在https://github.com/boctor/idev-recipes/tree/master/RaisedCenterTabBar获得完整的源代码