Add a gesture to a component

[densen2014]

Like https://learn.microsoft.com/en-us/mobile-blazor-bindings/ui/gestures

概述
手势识别器可用于检测用户与应用程序中的视图的交互。

手势识别器附加到控件并指定要响应的手势以及处理响应的事件。支持点击、捏合、平移和滑动等手势。手势可以添加到派生自View或的任何组件中GestureElement。

伪代码:

<ContentView>
    <StackLayout>

        <Label Text="...">
            <TapGestureRecognizer NumberOfTapsRequired="1" OnTapped="@OnLabelTapped" />
            <PanGestureRecognizer OnPanUpdated="@OnLabelPanned" />
            <SwipeGestureRecognizer Direction="SwipeDirection.Left" OnSwiped="@OnLabelSwiped" />
            <SwipeGestureRecognizer Direction="SwipeDirection.Right" OnSwiped="@OnLabelSwiped" />
            <PinchGestureRecognizer OnPinchUpdated="@OnLabelPinched" />
        </Label>

    </StackLayout>
</ContentView>

@code
{
    void OnLabelTapped()
    {
        // TODO: Response to tap gesture

        StateHasChanged();
    }

    void OnLabelPanned(PanUpdatedEventArgs e)
    {
        // TODO: Response to pan gesture

        // Check e.StatusType, e.TotalX, and e.TotalY

        StateHasChanged();
    }

    void OnLabelSwiped(SwipedEventArgs e)
    {
        // TODO: Response to swipe gesture

        // Check e.Direction

        StateHasChanged();
    }

    void OnLabelPinched(PinchGestureUpdatedEventArgs e)
    {
        // TODO: Response to pinch gesture

        // Check e.Scale, e.ScaleOrigin, and e.Status

        StateHasChanged();
    }
}