iOS8 自訂navigationbar 以及 UIBarButtonItem 邊距問題

iOS8 自訂navigationbar 以及 UIBarButtonItem 邊距問題

一。自訂navigationbar

 

- (void)initNavigationBar{    [self.navigationController setNavigationBarHidden:YES];    UINavigationBar *bar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, 320, 32)];    [bar setBackgroundImage:[UIImage imageNamed:@zhuche_bar2.png] forBarMetrics:UIBarMetricsDefault];     UINavigationItem *item = [[UINavigationItem alloc] initWithTitle:nil];    UIButton *left = [UIButton buttonWithType:UIButtonTypeCustom];    [left setFrame:CGRectMake(0, 2, 28, 28)];    [left setImage:[UIImage imageNamed:@zhuche_back.png] forState:UIControlStateNormal];    [left addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];    UIBarButtonItem *leftButton = [[UIBarButtonItem alloc] initWithCustomView:left];    [item setLeftBarButtonItem:leftButton];    [bar pushNavigationItem:item animated:NO];    [self.view addSubview:bar];}- (void)back{    [self.navigationController popViewControllerAnimated:YES];}

雖然可以解決自訂navigationbar的問題，左右按鈕都可以替換，但是如果放在UITableViewController中，自訂的navigationbar會隨著scrollview的滑動而滑動，不會像系統內建的navigationbar一樣始終保持在螢幕最上方。那麼我們可以有第二種解決方式，修改原來的navigationbar，其實就是改一下leftBarButtonItem或者rightBarButtonItem在navigationbar上面的位置：修改UIBarButtonItem 的邊距。

二。修改UIBarButtonItem 的邊距

@interface UINavigationItem (margin)@end@implementation UINavigationItem (margin)#if __IPHONE_OS_VERSION_MAX_ALLOWED > __IPHONE_6_1- (void)setLeftBarButtonItem:(UIBarButtonItem *)_leftBarButtonItem{    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)    {        UIBarButtonItem *negativeSeperator = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];        negativeSeperator.width = -16;//此處修改到邊界的距離，請自行測試                if (_leftBarButtonItem)        {            [self setLeftBarButtonItems:@[negativeSeperator, _leftBarButtonItem]];        }        else        {            [self setLeftBarButtonItems:@[negativeSeperator]];        }                   }    else    {        [self setLeftBarButtonItem:_leftBarButtonItem animated:NO];    }}- (void)setRightBarButtonItem:(UIBarButtonItem *)_rightBarButtonItem{    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)    {        UIBarButtonItem *negativeSeperator = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];        negativeSeperator.width = -12;//此處修改到邊界的距離，請自行測試                if (_rightBarButtonItem)        {            [self setRightBarButtonItems:@[negativeSeperator, _rightBarButtonItem]];        }        else        {            [self setRightBarButtonItems:@[negativeSeperator]];        }            }    else    {        [self setRightBarButtonItem:_rightBarButtonItem animated:NO];    }}#endif@end

以上代碼可以放置在主視圖控制器的.m檔案裡面，@implementation ViewController的上面。