向导航栏添加刷新按钮

Question

大家好我很痛苦的时候试图让这个导航栏包含一个刷新按钮,如果你可以看看下面的代码,然后提供一些帮助这是我的原始代码以及我发现刷新的UIBarbutton片段谷歌上另一个用户项目的按钮.我遇到了以下错误:

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self.tableView setBackgroundView:nil];
    self.tableView.backgroundColor = [ColorHelper charcoalBackgroundImage];
    UIBarButtonItem *refresh = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh target:self action:@selector(refresh:)];
    self.navigationItem.leftBarButtonItem = refresh;
    // [button release]; remove this line if you're using ARC
}
- (void) refresh
{

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

Answer 1

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self.tableView setBackgroundView:nil];
    self.tableView.backgroundColor = [ColorHelper charcoalBackgroundImage];

    UIBarButtonItem *button = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh target:self action:@selector(refresh:)];
    self.navigationItem.rightBarButtonItem = button;
}

将此方法写为此,因为您在调用中传递UIBarButton对象.

- (void) refresh:(id)sender
{

}

要么

UIBarButtonItem *button = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh target:self action:@selector(refresh)];