UIBarButtonItem*negativeSpacer=[[UIBarButtonItemalloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpacetarget:nilaction:nil];negativeSpacer.width=-10;UIButton*back2=[UIButtonbuttonWithType:UIButtonTypeSystem];[back2setFrame:CGRectMake(0,0,100*0.5,40*0.5)];[back2setBackgroundImage:[UIImagep_w_picpathNamed:@"back"]forState:UIControlStateNormal];UIBarButtonItem*back=[[UIBarButtonItemalloc]initWithCustomView:back2];self.navigationItem.leftBarButtonItems=@[negativeSpacer,back];