如何在UIToolbar上爲小尺寸類隱藏UIBarbuttonItem？

Question

很遺憾UIToolbar不支持UIBarbuttonItem元素的大小分類。如何在UIToolbar上隱藏UIBarbuttonItem的小尺寸課程？

Answer 1

首先，補充一點：

- (void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection { 
    [super traitCollectionDidChange:previousTraitCollection]; 
    if ((self.traitCollection.verticalSizeClass != previousTraitCollection.verticalSizeClass) 
     || (self.traitCollection.horizontalSizeClass != previousTraitCollection.horizontalSizeClass)) { 
     [self setupToolbar:self.traitCollection.horizontalSizeClass]; 
    } 
} 

，然後重新創建工具欄項目：

if (horizontalSizeClass == UIUserInterfaceSizeClassCompact) { 
     mainItems = [NSArray arrayWithObjects:..., nil]; 
    } else { 
     mainItems = [NSArray arrayWithObjects:..., nil]; 
    } 
    [mainToolbar setItems:mainItems animated:NO];