ios - 如何检查按钮是否有此图像

Question

我想检查 myButton 是否有命名图像。

我试过了，没用

if (myButton.currentImage?.isEqual(UIImage(named: "ButtonAppuyer.png")) != nil){
        print("YES")
    } else {
        print("NO")
    }

这也行不通

if myButton.currentImage?.isEqual(UIImage(named: "ButtonAppuyer.png")){
        print("YES")
    } else {
        print("NO")
    }

Answer 1

这是我在 Swift 3.0 中的想法。

if let myButtonImage = myButton.image(for: .normal),
    let buttonAppuyerImage = UIImage(named: "ButtonAppuyer.png"),
    UIImagePNGRepresentation(myButtonImage) == UIImagePNGRepresentation(buttonAppuyerImage)
{
    print("YES")
} else {
    print("NO")
}

这可以清理很多。

extension UIButton {
    func hasImage(named imageName: String, for state: UIControlState) -> Bool {
        guard let buttonImage = image(for: state), let namedImage = UIImage(named: imageName) else {
            return false
        }

        return UIImagePNGRepresentation(buttonImage) == UIImagePNGRepresentation(namedImage)
    }
}

然后使用它

if myButton.hasImage(named: "ButtonAppuyer.png", for: .normal) {
    print("YES")
} else {
    print("NO")
}