Question

我写了自定义控件：

public class ExtendedImage : View
    {
        public string SourceStart { get; set; }
        public string SourceComplete { get; set; }
    }

当我在我的pcl项目中使用它时，我添加了tapGestureRecognizer。此识别器具有可绑定命令：

var image = new ExtendedImage()
    {
        SourceStart = "im1.png"),
        SourceComplete = "im2.png"),
    };
var tap = new TapGestureRecognizer();
tap.SetBinding(TapGestureRecognizer.CommandProperty, "imageCommand");
image.GestureRecognizers.Add(tap);

我有ImageRenderer：

public class iOSImageRenderer : ViewRenderer<ExtendedImage, UIImageView>
    {
        UIImageView image { get; set; }

        string SourceStart { get; set; }

        string SourceComplete { get; set; }

        protected override void OnElementChanged(ElementChangedEventArgs<ExtendedImage> e)
        {
            base.OnElementChanged(e);

            if(e.OldElement != null || this.Element == null)
                return;

            SourceStart = Element.SourceStart;
            SourceComplete = Element.SourceComplete;

            image = new UIImageView(UIImage.FromFile(SourceStart));
            image.UserInteractionEnabled = true;

            SetNativeControl(image);
        }

        public override void TouchesBegan(NSSet touches, UIEvent evt)
        {
            base.TouchesBegan(touches, evt);
            UITouch touch = touches.AnyObject as UITouch;
            if(touch != null)
            {
                image.Image = UIImage.FromFile(SourceComplete);
            }
        }

        public override void TouchesEnded(NSSet touches, UIEvent evt)
        {
            base.TouchesBegan(touches, evt);
            UITouch touch = touches.AnyObject as UITouch;
            if(touch != null)
            {
                image.Image = UIImage.FromFile(SourceStart);
            }
        }
}

可绑定识别器不适用于此解决方案。我有相同的windowsPhone渲染器，它的工作完美。对于Android我还没有检查。我如何在ios渲染器中绑定此命令，或者如何解决此问题？

Answer 1

我怀疑你的TouchesBegan / TouchesEnded妨碍了UITapGestureRecognizer。

您应首先修复TouchesEnded实施，以便调用base.TouchesEnded而不是base.TouchesBegan。

Xamarin表示在ios渲染器中不起作用的绑定

1 个答案: