ios - 按下 iOS swift 后更改 UIBarButtonItem 图标

Question

在 viewDidload 方法中，我声明了一个按钮并设置了 RightBarButton...

    let btnFavourite = UIButton(frame: CGRectMake(0,0,30,30))
    btnFavourite.addTarget(self, action: "btnFavourite:", forControlEvents: .TouchUpInside)
    btnFavourite.setImage(UIImage(named: "star"), forState: .Normal)
    btnFavourite.setImage(UIImage(named: "star_filled"), forState: .Highlighted)
    let rightButton = UIBarButtonItem(customView: btnFavourite)
    self.navigationItem.setRightBarButtonItems([rightButton], animated: true)

我如何按下图像“star.png”中的按钮然后更改为“star_filled.png”？然后按按钮从“star_filled.png”到“star.png”？

如何使两个函数像

func btnFavourite()
{
    //clicked the favourite button then image change to star_filled.png
}

fun btnUnfavourite()
{
    //clicked the button then the bar button image change to star.png
}

Answer 1

创建方法，该方法将根据 self.isFavourited 的状态更新您的 Button

var isFavourited = false;//declare this above the viewDidload()

func updateRighBarButton(isFavourite : Bool){
    let btnFavourite = UIButton(frame: CGRectMake(0,0,30,30))
    btnFavourite.addTarget(self, action: "btnFavouriteDidTap", forControlEvents: .TouchUpInside)


    if isFavourite {
         btnFavourite.setImage(UIImage(named: "star_filled"), forState: .Normal)
    }else{
        btnFavourite.setImage(UIImage(named: "star"), forState: .Normal)
    }
    let rightButton = UIBarButtonItem(customView: btnFavourite)
    self.navigationItem.setRightBarButtonItems([rightButton], animated: true)
}



func btnFavouriteDidTap()
{
    //do your stuff
    self.isFavourited = !self.isFavourited;
    if self.isFavourited {
        self.favourite();
    }else{
        self.unfavourite();
    }
    self.updateRighBarButton(self.isFavourited);
}


func favourite()
{
    //do your favourite stuff/logic
}

func unfavourite(){
    //do your unfavourite logic
}

在viewDidload方法中，第一次调用，即

self.updateRighBarButton(self.isFavourited);//first time self.isFavourited will be false