見程式碼

UIButton *btn=[UIButton buttonWithType:UIButtonTypeCustom];

btn.frame = CGRectMake(0, 0, 44, 44);

btn.adjustsImageWhenHighlighted = NO;

[btn setImage:[UIImage imageNamed:imageName] forState:UIControlStateNormal];

[btn addTarget:self action:Action forControlEvents:UIControlEventTouchUpInside];

UIBarButtonItem *item=[[UIBarButtonItem alloc]initWithCustomView:btn];

UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];

negativeSpacer.width = -12;//ios7以後右邊距預設值18px，負數相當於右移，正數左移

self.navigationItem.leftBarButtonItems=@[negativeSpacer,item];