ios - 集中中央标签栏按钮

Question

怎么做？中央标签栏按钮的圆顶效果？这是圆顶图像在规则中央形状的选项卡按钮顶部的简单投影吗？还是还有什么？

Answer 1

您可以通过

    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];

请检查以下链接:
http://idevrecipes.com/2010/12/16/raised-center-tab-bar-button/

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