Question

我需要一个可以响应单击/点击和双击/点按的控件。我发现如果我想同时处理单击和双击/点击，我就无法使用TapGestureRecognizer。所以，我试图扩展一个Label控件，添加一个Click事件处理程序。我尝试了以下代码，但事件不会触发。有什么建议？谢谢！

in LabelClickable.cs: ... public class LabelClickable : Label { public event EventHandler Clicked; public virtual void OnClicked() { Clicked?.Invoke(this, EventArgs.Empty); } } ... in MainPage.XAML: ... <local:LabelClickable Text="0" Clicked="Button_Clicked"/> ... and in MainPage.Xaml.cs: ... private void Button_Clicked(object sender, EventArgs e) { //do something; } ...

Answer 1

这是完整的工作解决方案（感谢Jason的建议！）：

public class LabelClickable: Label
{
    public LabelClickable()
    {
        TapGestureRecognizer singleTap = new TapGestureRecognizer()
        {
            NumberOfTapsRequired = 1
        };
        TapGestureRecognizer doubleTap = new TapGestureRecognizer()
        {
            NumberOfTapsRequired = 2
        };
        this.GestureRecognizers.Add(singleTap);
        this.GestureRecognizers.Add(doubleTap);
        singleTap.Tapped += Label_Clicked;
        doubleTap.Tapped += Label_Clicked;
    }

    private static int clickCount;

    private void Label_Clicked(object sender, EventArgs e)
    {
        if (clickCount < 1)
        {
            TimeSpan tt = new TimeSpan(0, 0, 0, 0, 250);
            Device.StartTimer(tt, ClickHandle);
        }
        clickCount++;
    }

    bool ClickHandle()
    {
        if (clickCount > 1)
        {
            Minus1();
        }
        else
        {
            Plus1();
        }
        clickCount = 0;
        return false;
    }

    private void Minus1()
    {
        int value = Convert.ToInt16(Text) - 1;
        if (value < 0)
            value = 0;
        Text = value.ToString();
    }

    private void Plus1()
    {
        Text = (Convert.ToInt16(Text) + 1).ToString();
    }
}

MainPage.xaml上的用法：

<local:LabelClickable Text="0" Grid.Row="0" Grid.Column="0" BackgroundColor="Transparent" FontSize="Large" FontAttributes="Bold" HorizontalTextAlignment="Center"/>

MainPage.xaml.cs上不需要任何其他内容。

兼作单头和双头的魅力！结果是显示计数器的可点击标签;计数器在单击时递增，在双击时递减。

Answer 2

TappedGestureRecognizer sng = new TappedGestureRecognizer();
TappedGestureRecognizer dbl = new TappedGestureRecognizer();
dbl.NumberOfTapsRequired = 2;
sng.Tapped += OnSingleTap;
dbl.Tapped += OnDoubleTap;

// assuming you're within a Control's context
this.GestureRecognizers.Add(sng);
this.GestureRecognizers.Add(dbl);

protected void OnSingleTap(object sender, EventArgs e) {
}

protected void OnDoubleTap(object sender, EventArgs e) {
}

扩展标签控件 - 添加Click事件处理程序

2 个答案: