Xamarin表单向左滑动/向右滑动手势-Java 学习之路

我想通过说我对移动开发，Xamarin，C＃， . Net完全陌生而言 .

我正在努力使用Xamarain Forms创建一个移动应用程序，并且遇到了无法使用滑动手势的问题，至少根据我看到的文档 .

我找到了这个网站：http://arteksoftware.com/gesture-recognizers-with-xamarin-forms/

这描述了如何为IOS / Android添加一些额外的手势，以便在表单的上下文中访问 . 在我尝试遵循这一点之前，我想看看是否有其他人已经在Xamarin Forms应用程序中实现了滑动以及它们是如何实现的 .

我的目标是必须有一个水平堆栈布局 . 此布局包含7个按钮，每个按钮反映当前一周的一天 . 在堆栈布局上向左滑动会将按钮的文本更改为上一周 . 向右滑动会将按钮的文本更改为下周 .

所以我也尝试使用MVVM和XAML . 那么我可以分开向左滑动和向右滑动动作吗？我想使用ICommand根据滑动的方向将某个参数传递给函数 .

任何这个或任何建议的例子将不胜感激 .

6 回答

基于@Ranjith Kumar的解决方案，我想出了以下内容：

public delegate void SwipedEventHandler(ISwipeListener sender, SwipedEventArgs e);

public class SwipedEventArgs : EventArgs
{
    readonly double _x;
    public double X => _x;

    readonly double _y;
    public double Y => _y;

    readonly View _view;
    public View View => _view;

    public SwipedEventArgs(View view, double x, double y)
    {
        _view = view;
        _x = x;
        _y = y;
    }
}

public interface ISwipeListener
{
    event SwipedEventHandler SwipedDown;

    event SwipedEventHandler SwipedLeft;

    event SwipedEventHandler SwipedNothing;

    event SwipedEventHandler SwipedRight;

    event SwipedEventHandler SwipedUp;

    double TotalX
    {
        get;
    }

    double TotalY
    {
        get;
    }
}

public class SwipeListener : PanGestureRecognizer, ISwipeListener
{
    public event SwipedEventHandler SwipedDown;

    public event SwipedEventHandler SwipedLeft;

    public event SwipedEventHandler SwipedNothing;

    public event SwipedEventHandler SwipedRight;

    public event SwipedEventHandler SwipedUp;

    double _totalX = 0, _totalY = 0;

    public double TotalX => _totalX;

    public double TotalY => _totalY;

    readonly View _view;

    public SwipeListener(View view) : base()
    {
        _view = view;
        _view.GestureRecognizers.Add(this);
        PanUpdated += OnPanUpdated;
    }

    void OnPanUpdated(object sender, PanUpdatedEventArgs e)
    {
        switch (e.StatusType)
        {
            case GestureStatus.Running:
                try
                {
                    _totalX = e.TotalX;
                    _totalY = e.TotalY;
                }
                catch (Exception exception)
                {
                    Debug.WriteLine(exception.Message);
                }
                break;

            case GestureStatus.Completed:
                if (_totalX < 0 && Math.Abs(_totalX) > Math.Abs(_totalY))
                {
                    OnSwipedLeft(_totalX, _totalY);
                }
                else if (_totalX > 0 && _totalX > Math.Abs(_totalY))
                {
                    OnSwipedRight(_totalX, _totalY);
                }
                else if (_totalY < 0 && Math.Abs(_totalY) > Math.Abs(_totalX))
                {
                    OnSwipedUp(_totalX, _totalY);
                }
                else if (_totalY > 0 && _totalY > Math.Abs(_totalX))
                {
                    OnSwipedDown(_totalX, _totalY);
                }
                else OnSwipedNothing(_totalX, _totalY);
                break;

        }
    }

    protected virtual void OnSwipedDown(double x, double y)
        => SwipedDown?.Invoke(this, new SwipedEventArgs(_view, x, y));

    protected virtual void OnSwipedLeft(double x, double y)
        => SwipedLeft?.Invoke(this, new SwipedEventArgs(_view, x, y));

    protected virtual void OnSwipedNothing(double x, double y)
        => SwipedNothing?.Invoke(this, new SwipedEventArgs(_view, x, y));

    protected virtual void OnSwipedRight(double x, double y)
        => SwipedRight?.Invoke(this, new SwipedEventArgs(_view, x, y));

    protected virtual void OnSwipedUp(double x, double y)
        => SwipedUp?.Invoke(this, new SwipedEventArgs(_view, x, y));
}

缺点是，只有在执行滑动后才能执行任何操作 .

回复于 2024-04-20T19:51:38+08:00

6

如果您使用Xamarin Forms，那么这是一个很好的可能性），MR.Gestures支持所有Xamarin.Forms视图上的所有触摸手势 . 我成功地使用它并且非常满意它 . 它的成本非常合理10欧元，并且具有出色的文档 .

如果您在Xamarin Forms中支持，请考虑投票this suggestion at UserVoice .

回复于 2024-04-20T19:51:38+08:00

不需要第三方库..无需支付..只需添加这两个类并实现您的滑动监听器

Step 1: Copy paste these two classes

SwipeListener.cs

using System;
using Xamarin.Forms;

namespace SwipeLib
{
public class SwipeListener : PanGestureRecognizer
{
    private ISwipeCallBack mISwipeCallback;
    private double translatedX = 0, translatedY = 0;

    public SwipeListener(View view, ISwipeCallBack iSwipeCallBack)
    {
        mISwipeCallback = iSwipeCallBack;
        var panGesture = new PanGestureRecognizer();
        panGesture.PanUpdated += OnPanUpdated;
        view.GestureRecognizers.Add(panGesture);
    }

    void OnPanUpdated(object sender, PanUpdatedEventArgs e)
    {

        View Content = (View)sender;

        switch (e.StatusType) {

            case GestureStatus.Running:

                try {
                    translatedX = e.TotalX;
                    translatedY = e.TotalY;
                } catch (Exception err) {
                    System.Diagnostics.Debug.WriteLine("" + err.Message);
                }
                break;

            case GestureStatus.Completed:

                System.Diagnostics.Debug.WriteLine("translatedX : " + translatedX);
                System.Diagnostics.Debug.WriteLine("translatedY : " + translatedY);

                if (translatedX < 0 && Math.Abs(translatedX) > Math.Abs(translatedY)) {
                    mISwipeCallback.onLeftSwipe(Content);
                } else if (translatedX > 0 && translatedX > Math.Abs(translatedY)) {
                    mISwipeCallback.onRightSwipe(Content);
                } else if (translatedY < 0 && Math.Abs(translatedY) > Math.Abs(translatedX)) {
                    mISwipeCallback.onTopSwipe(Content);
                } else if (translatedY > 0 && translatedY > Math.Abs(translatedX)) {
                    mISwipeCallback.onBottomSwipe(Content);
                } else {
                    mISwipeCallback.onNothingSwiped(Content);
                }

                break;

        }
    }

}
}

ISwipeCallBack.cs

using System;
using Xamarin.Forms;
namespace SwipeLib
{  
public interface ISwipeCallBack
{

    void onLeftSwipe(View view);
    void onRightSwipe(View view);
    void onTopSwipe(View view);
    void onBottomSwipe(View view);
    void onNothingSwiped(View view);
}
}

Step 2: From your Xamarin forms pass the view & also interface obj. Then you get result

在我的情况下，我通过了标签

SwipeListener swipeListener = new SwipeListener(lbl_swipe, this);

Step 3: Implement the ISwipeCallBack interface

public partial class SwipeLibPage : ContentPage, ISwipeCallBack

示例项目 - > https://github.com/rranjithkumar100/Xamarin-Swipe-Library

回复于 2024-04-20T19:51:38+08:00

您可以随时查看this简单演示 . 并使用如下：

GestureFrame gi = new GestureFrame
        {
            HorizontalOptions = LayoutOptions.FillAndExpand,
            VerticalOptions = LayoutOptions.FillAndExpand,
            BackgroundColor = Color.FromHex("bf3122"),
        };

        gi.SwipeDown += (s, e) =>
        {
            DisplayAlert("Gesture Info", "Swipe Down Detected", "OK");
            ViewModel.SampleCommand.Execute("Swipe Down Detected");
        };

        gi.SwipeTop += (s, e) =>
        {
            DisplayAlert("Gesture Info", "Swipe Top Detected", "OK");
            ViewModel.SampleCommand.Execute("Swipe Top Detected");
        };

        gi.SwipeLeft += (s, e) =>
        {
            DisplayAlert("Gesture Info", "Swipe Left Detected", "OK");
            ViewModel.SampleCommand.Execute("Swipe Left Detected");
        };

        gi.SwipeRight += (s, e) =>
        {
            DisplayAlert("Gesture Info", "Swipe Right Detected", "OK");
            ViewModel.SampleCommand.Execute("Swipe Right Detected");
        };

        this.Content = gi;

回复于 2024-04-20T19:51:38+08:00

0
也许这可以帮助某人 .

我遇到了一个问题：有一个带有scrollview和grid的ContentPage . 我需要做的就是处理向左/向右滑动手势 . 在搜索了google / stackoverflow / github之后，我找到了一个名为XamarinFormsGestures的Nuget包 . 这对我帮助很大 . 所有指令都在链接内 . 有我的代码：
```
Vapolia.Lib.Ui.Gesture.SetSwipeLeftCommand(scrollviewgrid, 
new Command(() => { OnLeftSwipe(); })); // What's going on when left swiped.
Vapolia.Lib.Ui.Gesture.SetSwipeRightCommand(scrollviewgrid, 
new Command(() => { OnRightSwipe(); })); // What's going on when right swiped.
```
回复于 2024-04-20T19:51:38+08:00
10

您可以使用Vapolia的NuGet包"XamarinFormsGesture"（doc available here） . 它免费且易于使用 .

可在iOS和Android上使用，但它仅适用于物理设备（不适用于模拟器） .

回复于 2024-04-20T19:51:38+08:00

Xamarin表单向左滑动/向右滑动手势

6 回答

相关问题