ios - swift 3 : expression pattern of type 'Int' cannot match values of type 'UnsafeMutableRawPointer'

Question

我正在将一个应用程序迁移到 Swift 3，但 Xcode 对此函数抛出错误:

错误是在 case condition ("contentSize", MyObservationContext)我这样做是为了更新 uiwebview 的内容大小

var MyObservationContext = 0
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    guard let keyPath = keyPath else {
        super.observeValue(forKeyPath: nil, of: object, change: change, context: context)
        return
    }
    switch (keyPath, context) {
    case("contentSize", MyObservationContext):
        webviewHeightConstraint.constant = TextoHtml.scrollView.contentSize.height
    default:
        super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)
    }
}

我愿意接受建议，谢谢。

Answer 1

案例需要

case("contentSize", .some(&MyObservationContext)):

.some 是确保上下文不为nil

& 获取指向 MyObservationContext 的指针，因此它可以将指针与指针进行比较。