Question

我有一个在视图上执行动画的功能。我想为这个函数实现一个完成处理程序，它将在动画完成后调用。

在ViewController中......

hudView.hide(animated: true, myCompletionHandler: {
    // Animation is complete
})

在HudView类中......

func hide(animated: Bool, myCompletionHandler: () -> Void) {
    if animated {
        transform = CGAffineTransform(scaleX: 0.7, y: 0.7)

        UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [], animations: {
            self.alpha = 0
            self.transform = CGAffineTransform.identity
        }, completion: nil) // I want to run 'myCompletionHandler' in this completion handler
    }
}

我尝试了很多东西，却找不到正确的语法：

}, completion: myCompletionHandler)

将非转义参数'myCompletionHandler'传递给期望的函数 @escaping关闭

}, completion: myCompletionHandler())

无法将'Void'类型的值转换为预期的参数类型'（（Bool） - ＆GT;空隙）？“

}, completion: { myCompletionHandler() })

关闭使用非转义参数'myCompletionHandler'可能允许它逸出

作为一个快速的新手，这些错误消息对我来说并不是很重要，我似乎无法找到正确方法的任何示例。

将myCompletionHandler传递给.animate完成处理程序的正确方法是什么？

Answer 1

如果要将自己的闭包作为输入参数传递给<kendo-grid [kendoGridGroupBinding]="data" [groupable]="true" [sortable]="true" [pageSize]="80" [rowHeight]="35" [height]="460" scrollable="virtual" (groupChange)="groupChange($event)" > <kendo-grid-column field="id" [width]="80" title="ID"></kendo-grid-column> <kendo-grid-column field="firstName" title="First Name" [width]="130"></kendo-grid-column> <kendo-grid-column field="lastName" title="Last Name" [width]="130"></kendo-grid-column> <kendo-grid-column field="city" title="City" [width]="130"></kendo-grid-column> <kendo-grid-column field="title" title="Title" [width]="180"></kendo-grid-column> </kendo-grid> public groupChange(groups: GroupDescriptor[]): void { console.log('groupChange', groups); this.collapseAllGroups(groups); } public collapseAllGroups(groups): void { if (this.grid && groups.length > 0) { for (let i = 0; i < this.data.length; i++) { this.grid.collapseGroup(i.toString()); } this.collapsed = true; } }，则需要匹配闭包的类型，因此UIView.animate的类型必须为myCompletionHandler，就像((Bool) -> ())?。

completion

您可以这样称呼它：

func hide(animated: Bool, myCompletionHandler: ((Bool) -> ())?) {
    if animated {
        transform = CGAffineTransform(scaleX: 0.7, y: 0.7)

        UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [], animations: {
            self.alpha = 0
            self.transform = CGAffineTransform.identity
        }, completion: myCompletionHandler) // I want to run 'myCompletionHandler' in this completion handler
    }
}

Answer 2

这是在UIView.animate中使用完成的方法：

func hide(animated: Bool, myCompletionHandler: () -> Void) {
    if animated {
        transform = CGAffineTransform(scaleX: 0.7, y: 0.7)

        UIView.animate(withDuration: 0.3, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [], animations: {
            self.alpha = 0
            self.transform = CGAffineTransform.identity
        }, completion: { (success) in
            myCompletionHandler()
        })
    }
}

Answer 3

You can create your function as,

func hide(_ animated:Bool, completionBlock:((Bool) -> Void)?){

}

And you can call it as,

self.hide(true) { (success) in
   // callback here     
}

传递函数到完成处理程序

3 个答案: