在导航栏上添加自定义后退按钮

Question

我试图在导航栏上添加自定义后退按钮,但它不起作用我的代码

-(void)addLeftButton
{
    UIImage *buttonImage = [UIImage imageNamed:@"btn_back.png"];

    UIButton *aButton = [UIButton buttonWithType:UIButtonTypeCustom];

    [aButton setBackgroundImage:buttonImage forState:UIControlStateNormal];

    aButton.frame = CGRectMake(0.0, 0.0, buttonImage.size.width,   buttonImage.size.height);

    UIBarButtonItem *aBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:aButton];

   [aButton addTarget:self action:nil forControlEvents:UIControlEventTouchUpInside];

   self.navigationItem.backBarButtonItem = aBarButtonItem;
}  

请告诉我这段代码有什么问题

Answer 1

试试这个.

-(void)addLeftButton
{
     UIImage *buttonImage = [UIImage imageNamed:@"btn_back.png"];

     UIButton *aButton = [UIButton buttonWithType:UIButtonTypeCustom];

     [aButton setBackgroundImage:buttonImage forState:UIControlStateNormal];

     aButton.frame = CGRectMake(0.0, 0.0, buttonImage.size.width,   buttonImage.size.height);

     UIBarButtonItem *aBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:aButton];

     [aButton addTarget:self action:nil forControlEvents:UIControlEventTouchUpInside];

     [self.navigationItem setLeftBarButtonItem:aBarButtonItem];
}