UITabBar selectionIndicatorImage填充

Question

我UITabBar为此设置了自定义指标图像

UIImage *tabBarSelectedImage = [[UIImage imageNamed:@"tabBar_selected"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)];
[[UITabBar appearance] setSelectionIndicatorImage:tabBarSelectedImage];

并在我的周围获得4px填充tabBarSelectedImage.是否可以将填充设置为0px？这样我tabBarSelectedImage填满了整个空间,没有边框可见？

Answer 1

这是你的问题的解决方案...我实际上并没有这样做...我正在做其他事情,但以下代码将帮助你很多....首先我告诉你我做了什么...

1. 我做了一个类别UITabbar并实现了以下方法

   - (void)recolorItemsWithColor:(UIColor *)color shadowColor:(UIColor *)shadowColor 
   shadowOffset:(CGSize)shadowOffset shadowBlur:(CGFloat)shadowBlur
   {
   CGColorRef cgColor = [color CGColor];
   CGColorRef cgShadowColor = [shadowColor CGColor];
   for (UITabBarItem *item in [self items]) {
   
   if ([item respondsToSelector:@selector(selectedImage)] &&
       [item respondsToSelector:@selector(setSelectedImage:)] &&
       [item respondsToSelector:@selector(_updateView)])
   {
       CGRect contextRect;
       contextRect.origin.x = 0.0f;
       contextRect.origin.y = 0.0f;
   
       //instead of following line you can give our own desired size of contextRect. 
       //just change the method parameters and include a parameter of desired size in it.
       // and this desired size would be the tabbarbutton size...so you will pass the size of 
       // you tabbarbutton here...because on the back of image there is a tabbarbutton and if
       // set the image of button size it will occupy whole the are of button.
   
       contextRect.size = desired size //[[item selectedImage] size];
       // Retrieve source image and begin image context
       UIImage *itemImage = [item image];
       CGSize itemImageSize = [itemImage size];
   
       CGPoint itemImagePosition; 
       itemImagePosition.x = ceilf((contextRect.size.width - itemImageSize.width) / 2);
       itemImagePosition.y = ceilf((contextRect.size.height - itemImageSize.height) / 2);
       UIGraphicsBeginImageContext(contextRect.size);
       CGContextRef c = UIGraphicsGetCurrentContext();
   
       // Setup shadow
       CGContextSetShadowWithColor(c, shadowOffset, shadowBlur, cgShadowColor);
   
       // Setup transparency layer and clip to mask
       CGContextBeginTransparencyLayer(c, NULL);
       CGContextScaleCTM(c, 1.0, -1.0);
       CGContextClipToMask(c, CGRectMake(itemImagePosition.x, -itemImagePosition.y,
       itemImageSize.width, -itemImageSize.height), [itemImage CGImage]);
   
       // Fill and end the transparency layer
       CGContextSetFillColorWithColor(c, cgColor);
       contextRect.size.height = -contextRect.size.height;
       CGContextFillRect(c, contextRect);
       CGContextEndTransparencyLayer(c);
   
   
       // Set selected image and end context
       [item setSelectedImage:UIGraphicsGetImageFromCurrentImageContext()];
       UIGraphicsEndImageContext();
       // Update the view
       [item _updateView];
      }
      }
   
      }
   

   现在我在我的自定义类UITabbarController中调用了上面的方法...我重写了该方法
   -(void)setSelectedIndex:(NSUInteger)selectedIndex并在该方法中执行了以下操作.

     -(void)setSelectedIndex:(NSUInteger)selectedIndex {
          self.selectedViewController = [self.viewControllers objectAtIndex:selectedIndex];
          NSLog(@"selectedIndex:%d, totalCount:%d",selectedIndex,[self.tabBar.subviews count]);
      for (uint i=1; i < [self.tabBar.subviews count]; i++)
      {
         UIView *view = [self.tabBar.subviews objectAtIndex:i];
         NSLog(@"class:%@",NSStringFromClass([view class]));
      if ([NSStringFromClass([view class]) isEqualToString:@"UITabBarButton"])
      {
       //view.frame = CGRectMake(view.frame.origin.x, view.frame.origin.y,  
       view.frame.size.width, self.tabBar.frame.size.height);
         NSLog(@"selectedIndex:%d,i:%d",self.selectedIndex,i);
       if (self.selectedIndex+1==i) {
           [self.tabBar recolorItemsWithColor:[UIColor whiteColor] shadowColor:[UIColor 
                               blackColor] shadowOffset:view.frame.size shadowBlur:0.5];
   
       }
       } 
       }
   
       }
   

您可以优化代码以避免进行类别或子类化......但为此您必须抓住目标C.如果有任何问题,您可以告诉我.干杯

Answer 2

我找到了一种更简单的解决方案：

self.tabBar.frame = CGRectInset(self.tabBar.frame,0,-6);