Question

我试图创建一个闪烁的BoxView。我创建了一个BlinkingBoxView，它扩展了BoxView并添加了一个名为＆＃34; Blink＆＃34;的布尔属性。所以我想要的是，每次Blink改变并且它的值是真的，我想开始闪烁动画，如果值为false则停止动画。

我需要在C＃代码中执行此操作，还是只能像WPF一样使用XAML？

这是我的尝试...

public class BlinkingBoxView : BoxView
{
    public BlinkingBoxView() 
        : base()
    {

    }

    public static readonly BindableProperty BlinkProperty = BindableProperty.Create<BlinkingBoxView, bool>(w => w.Blink, default(bool), BindingMode.TwoWay);

    public bool Blink
    {
        get { return (bool)GetValue(BlinkProperty); }
        set 
        {
            SetValue(BlinkProperty, value);

            var blinkAnimation = new Animation(d => this.FadeTo(0, 750, Easing.Linear)).WithConcurrent(new Animation(d => this.FadeTo(1, 750, Easing.Linear)));

            if (this.Blink)
                this.Animate("Blink", blinkAnimation);
        }
    }
}

Answer 1

您应该使用- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { tabBarController.delegate = self; return YES; } - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController { NSLog(@"Selected tab bar button!"); }覆盖来捕获属性更改：

OnPropertyChanged

您可以在XAML中使用它，与其他任何public class BlinkingBoxView : BoxView { volatile bool isBlinking; public static readonly BindableProperty BlinkProperty = BindableProperty.Create<BlinkingBoxView, bool>(w => w.Blink, default(bool), BindingMode.OneWay); public bool Blink { get { return (bool)GetValue(BlinkProperty); } set { SetValue(BlinkProperty, value); } } public static readonly BindableProperty BlinkDurationProperty = BindableProperty.Create<BlinkingBoxView, uint>(w => w.BlinkDuration, 500, BindingMode.OneWay); public uint BlinkDuration { get { return (uint)GetValue(BlinkDurationProperty); } set { SetValue(BlinkDurationProperty, value); } } protected override void OnPropertyChanged(string propertyName) { base.OnPropertyChanged(propertyName); if (propertyName == BlinkProperty.PropertyName) { SetBlinking(Blink); } if (propertyName == BlinkDurationProperty.PropertyName) { if (isBlinking) { SetBlinking(false); SetBlinking(Blink); } } } void SetBlinking(bool shouldBlink) { if (shouldBlink && !isBlinking) { isBlinking = true; var blinkAnimation = new Animation(((d) => { Opacity = d; }), 0f, 1f, Easing.SinInOut); this.Animate("BlinkingBoxViewBlink", blinkAnimation, length: BlinkDuration, repeat: () => isBlinking); } else if (!shouldBlink && isBlinking) { isBlinking = false; } } }一样。

Xamarin形成BoxView动画

1 个答案: