iOS 改变左右侧距离

• (void) initNavBar
  {
  UIButton *addBtn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 24, 24)];
  [addBtn setImage:[UIImage imageNamed:@"NewBack"] forState:UIControlStateNormal];
  [addBtn setContentHorizontalAlignment:UIControlContentHorizontalAlignmentLeft];
  [addBtn addTarget:self action:@selector(backBtnAction:) forControlEvents:UIControlEventTouchUpInside];
  UIBarButtonItem *leftBar = [[UIBarButtonItem alloc]initWithCustomView:addBtn];
  UIBarButtonItem *space = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
  space.width = 0.0f;
  if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 11.0){
  //改变文字
  // addBtn.contentEdgeInsets = UIEdgeInsetsMake(0, -50,0, 0);
  //改变图片
  addBtn.imageEdgeInsets = UIEdgeInsetsMake(0, -17,0, 0);
  }else{
  space.width = -17.0f;
  }
  NSArray *leftBarButtonItems = [NSArray arrayWithObjects: space, leftBar,nil ];
  [self.navigationItem setLeftBarButtonItems:leftBarButtonItems];

}