C# 持续时间是一种类型,但用作变量

本文关键字:类型 变量 一种 持续时间 | 更新日期: 2023-09-27 18:34:37

我正在遵循O'Reilly Media的"大脑友好指南:Head First C#"一书的步骤

并且遇到了此错误'Windows.UI.Xaml.Duration' is a 'type' but is used like a 'variable'

插入此代码时Duration = new Duration(TimeSpan.FromSeconds(random.Next(4, 6)));

想知道为什么我会收到此错误,我该怎么做才能解决它?

下面是书中描述的完整代码方法,如果它有帮助,如果它只是造成混乱并使用户难以阅读文本,我将删除该方法。

private void AnimateEnemy(ContentControl enemy, double from, double to, string propertyToAnimate)
        {
            Storyboard storyboard = new Storyboard() { AutoReverse = true, RepeatBehavior = RepeatBehavior.Forever };
            DoubleAnimation animation = new DoubleAnimation();
            {
                From = from;
                To = to;
                Duration = new Duration(TimeSpan.FromSeconds(random.Next(4, 6)))
           };
            Storyboard.SetTarget(animation, enemy);
            Storyboard.SetTargetProperty(animation, propertyToAnimate);
            storyboard.Children.Add(animation);
            storyboard.Begin();
            }

C# 持续时间是一种类型,但用作变量

编译器试图告诉您,您不能使用类型Duration的名称来命名匿名类型的字段,因为您的初始值设定项语法不正确:您在 new DoubleAnimation() 后放置了一个分号,因此初始值设定项的其余部分被视为独立的代码块。

这是正确的语法:

DoubleAnimation animation = new DoubleAnimation {
    From = from,
    To = to,
    Duration = new Duration(TimeSpan.FromSeconds(random.Next(4, 6)))
};

我删除了new DoubleAnimation后的括号,因为调用了默认构造函数。我还用逗号替换了分号以符合 C# 语法。

正如Jesse指出的,你应该去掉分号,用逗号代替它们:

private void AnimateEnemy(ContentControl enemy, double from, double to, string propertyToAnimate)
        {
            Storyboard storyboard = new Storyboard() { AutoReverse = true, RepeatBehavior = RepeatBehavior.Forever };
            DoubleAnimation animation = new DoubleAnimation()
            {
                From = from,
                To = to,
                Duration = new Duration(TimeSpan.FromSeconds(random.Next(4, 6)))
            };
                Storyboard.SetTarget(animation, enemy);
                storyboard.SetTargetProperty(animation, propertyToAnimate);
                storyboard.Children.Add(animation);
                storyboard.Begin();
            }