如何在longpress上显示弹出菜单？

Question

如何在longpress用户上显示自定义弹出页面？每个选项都必须有一个新闻事件。

我没有看到与此相关的话题，但是它们没有帮助。

这是我的代码：

for (int l = 1; l < ustkatmasasayisi; l++)
{
    var buttonustkat = new Button
    {
        Text = l.ToString(),
        HeightRequest = 45,
        WidthRequest = 45,
        Margin = 5,
        CornerRadius = 100,
    };
    buttonustkat.Clicked += ustkatbuton;
    ustkat.Children.Add(buttonustkat);
}

---

async void ustkatbuton(object o, EventArgs args)
{
    secilenmasa = buttonustkat.Text;
    secilenkonum = "Üst kat";
    await Navigation.PushModalAsync(new menu());
}

我必须在buttonustkat上设置longpress事件

Answer 1

您可以使用自定义渲染器

形式

创建自定义按钮

using System;

using Xamarin.Forms;
namespace App13
{
    public class MyButton:Button
    {
        public  EventHandler LongPress { get; set; }
    }
}

在iOS中

using System;

using UIKit;

using App13;
using App13.iOS;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(MyButton), typeof(MyButtonRenderer))]
namespace App13.iOS
{
    public class MyButtonRenderer:ButtonRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
        {
            base.OnElementChanged(e);

            if(Control!=null)
            {
                var longPress = new UILongPressGestureRecognizer(()=> {

                    var myButton = Element as MyButton;
                    myButton.LongPress?.Invoke(myButton, new EventArgs());
                
                });

                Control.AddGestureRecognizer(longPress);
            }
        }
    }
}

在Android中

using System;

using Android.Content;

using App13;
using App13.Droid;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly:ExportRenderer(typeof(MyButton),typeof(MyButtonRenderer))]
namespace App13.Droid
{
    public class MyButtonRenderer : ButtonRenderer
    {
        public MyButtonRenderer(Context context) : base(context)
        {
        }

        protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Button> e)
        {
            base.OnElementChanged(e);

            if(Control!=null)
            {
                Control.LongClick += Control_LongClick;
            }
        }

        private void Control_LongClick(object sender, LongClickEventArgs e)
        {
            var mybutton = Element as MyButton;
            mybutton.LongPress?.Invoke(mybutton,new EventArgs());
        }
    }
}

那么您就可以处理长按事件

var buttonustkat = new MyButton
    {
        Text = l.ToString(),
        HeightRequest = 45,
        WidthRequest = 45,
        Margin = 5,
        CornerRadius = 100,
    };
buttonustkat..LongPress += Button_LongPress;

private void Button_LongPress(object sender, EventArgs e)
{
            
}