Question

我正在创建一个自定义导航按钮，而不是它的默认外观。我能够创建按钮，但我遇到的问题是它的选择器。我想在不同类的方法中添加该按钮的选择器。我将UIViewController作为参数传递，因此我可以修改navigationBar。

-(void)addNavButton:(MyViewController *)vc
{
    UIImage *buttonImg = [UIImage imageNamed:@"back.png"];
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setImage:buttonImg forState:UIControlStateNormal];

    button.frame = CGRectMake(0, 0, buttonImg.size.width, buttonImg.size.height);

    [button addTarget:self action:@selector(vc.popBackNavigation) forControlEvents:UIControlEventTouchUpInside];  //Here is the line where I am having trouble

    UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];
    vc.navigationItem.leftBarButtonItem = customBarItem;
}

我这样做是因为我不想在每个类中添加相同的方法来定义customNavigation项。如果有一个简短的方法或有效的方法，请告诉我

Answer 1

在这种情况下，你需要针对不同的类。

请记住，目标是您要将邮件发送到的对象。所以在这种情况下，选择器是：

@selector(popBackNavigation)

，目标是vc。

，并提供：

[button addTarget:vc action:@selector(popBackNavigation) forControlEvents:UIControlEventTouchUpInside];

Answer 2

希望您正在寻找类似的东西：

@implementation Utility

+ (UIBarButtonItem *)addNavButton:(id)target withSelector:(SEL)selectorMethod
{
    UIImage *buttonImg = [UIImage imageNamed:@"back.png"];
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setImage:buttonImg forState:UIControlStateNormal];
    button.frame = CGRectMake(0, 0, buttonImg.size.width, buttonImg.size.height);
    [button addTarget:target action:selectorMethod forControlEvents:UIControlEventTouchUpInside];      
    UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:button];

    return customBarItem;
}

@end

从viewController中调用此方法，

@implementation Mycontroller

- (void)viewDidLoad
{
   [super viewDidLoad];
   UIBarButtonItem *leftItem = [Utility addNavButton:self withSelector:@selector(backbuttonAction)];
   self.navigationItem.leftBarButtonItem = leftItem;
}

@end

Answer 3

如果您想在应用中自定义此后退按钮，可以将此代码放入AppDelegate

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)options
{
 UIImage *buttonImg = [UIImage imageNamed:@"back.png"];

 [[UIBarButtonItem appearance] setBackButtonBackgroundImage:buttonImg  forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
 // customize the position if needed
 [[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, buttonImg.size.height*2) forBarMetrics:UIBarMetricsDefault];

 return yes;
}

如果没有任何进一步的互动，这将覆盖您应用的默认后退按钮样式。

我可以将选择器添加到其他类吗？

3 个答案: