以编程方式创建后退栏按钮

Question

我正在尝试以编程方式创建一个后退栏按钮，类似于 iOS 7 默认的后退按钮。但是当我将后栏按钮添加到导航项时。雪佛龙加号不见了。我怎样才能做到这一点？

Answer 1

    UIImage* image_back = [UIImage imageNamed:@"leftarrow.png"];
    CGRect backframe = CGRectMake(15, 5, 15,21);
    UIButton *backbutton = [[UIButton alloc] initWithFrame:backframe];
    [backbutton setBackgroundImage:image_back forState:UIControlStateNormal];
    [backbutton addTarget:self action:@selector(Btn_back:)
         forControlEvents:UIControlEventTouchUpInside];
    [backbutton setShowsTouchWhenHighlighted:YES];
    UIBarButtonItem *backbarbutton =[[UIBarButtonItem alloc] initWithCustomView:backbutton];
    self.navigationItem.leftBarButtonItem=backbarbutton;
    [backbutton release];
-(IBAction)Btn_back:(id)sender
{
    [self.navigationController popViewControllerAnimated:YES];

}