Silverlight中最干净的单击+双击处理？

时间：2009-08-13 20:27:39

标签： silverlight-3.0 double-click

我一直在寻找各种处理双击的方法，然后作者对一些代码进行单击处理。现在Silverlight 3中是否有一个标准，每个人都用它来处理列表框中的单击和双击？

6 个答案:

答案 0 :(得分：10)

如果使用Reactive Extensions (Rx)库，支持双击的代码要简单得多：

Observable.FromEvent<MouseButtonEventArgs>(myControl, "MouseLeftButtonDown").TimeInterval().Subscribe(evt =>
        {
            if (evt.Interval.TotalMilliseconds <= 300)
            {
                // Do something on double click
            }
        });

答案 1 :(得分：2)

轻松写一次使用.... 

 import YourProject.Utils; //must for using extentions

 button1.AddDoubleClickHandler((s, e) =>
            {
                Debug.WriteLine("You can use this DoubleClick extention method
                           for any UIElement in SL !");
            });

//这是我的工具

namespace YourProject.Utils
{
public class DoubleClick
{

    public DoubleClick()
    {
        this._lastClick = DateTime.Now;
    }

    private  TimeSpan DoubleClickThreshold = TimeSpan.FromMilliseconds(450);
    private  DateTime _lastClick;

    public event MouseButtonEventHandler MouseDoubleClick;

    public void DoubleClicked(object sender, MouseButtonEventArgs e)
    {
        if (DateTime.Now - this._lastClick <= DoubleClickThreshold)
        {
            MouseDoubleClick(sender, e);
        }
        this._lastClick = DateTime.Now;
    }

    internal void AddHandler(UIElement ctl)
    {
        ctl.AddHandler(UIElement.MouseLeftButtonUpEvent, new MouseButtonEventHandler(this.DoubleClicked), true);
    }
}

public static class DoubleClickExtentions
{
    public static void AddDoubleClickHandler(this UIElement ctl, MouseButtonEventHandler MouseDoubleClick)
    {
        DoubleClick doubleClick = new DoubleClick();
        doubleClick.MouseDoubleClick += MouseDoubleClick;

        doubleClick.AddHandler(ctl);
    }
}
}

答案 2 :(得分：1)

我喜欢这种方法： http://www.domagoj.pavlesic.com/DoubleClick-in-Silverlight

优点：您可以单击，双击和单击延迟事件（因此您可以确定，不会出现双击）。

答案 3 :(得分：0)

我已经实施了一种干净的方式来根据以下文章的方法注册DoubleClick事件：

http://yinyangme.com/blog/post/The-simplest-way-to-detect-DoubleClick-in-Silverlight.aspx http://www.domagoj.pavlesic.com/DoubleClick-in-Silverlight

要使用它，您只需要通过扩展方法注册/取消注册处理程序：

element.AddDoubleClickHandler(Element_DoubleClick);
element.RemoveDoubleClickHandler(Element_DoubleClick);

以下是代码：

    using System;
using System.Windows;
using System.Windows.Input;

namespace System.Windows
{
    public class DoubleClickHelper
    {
        private const long DoubleClickSpeed = 500;
        private const double MaxMoveDistance = 10;

        private static long lastClickTicks = 0;
        private static Point lastPosition;
        private static WeakReference lastSender;

        internal static bool IsDoubleClick(object sender, MouseButtonEventArgs e)
        {
            Point position = e.GetPosition(null);
            long clickTicks = DateTime.Now.Ticks;
            long elapsedTicks = clickTicks - lastClickTicks;
            long elapsedTime = elapsedTicks / TimeSpan.TicksPerMillisecond;
            bool quickClick = (elapsedTime <= DoubleClickSpeed);
            bool senderMatch = (lastSender != null && sender.Equals(lastSender.Target));

            if (senderMatch && quickClick && DoubleClickHelper.Distance(position, lastPosition) <= MaxMoveDistance)
            {
                // Double click!
                lastClickTicks = 0;
                lastSender = null;
                return true;
            }

            // Not a double click
            lastClickTicks = clickTicks;
            lastPosition = position;
            if (!quickClick)
                lastSender = new WeakReference(sender);
            return false;
        }

        private static double Distance(Point pointA, Point pointB)
        {
            double x = pointA.X - pointB.X;
            double y = pointA.Y - pointB.Y;
            return Math.Sqrt(x * x + y * y);
        }

        public bool HasHandlers { get { return this.MouseDoubleClick != null; } }

        private WeakReference target;

        public event MouseButtonEventHandler MouseDoubleClick;
        private void OnMouseDoubleClick(MouseButtonEventArgs args)
        {
            if (this.MouseDoubleClick != null && this.target.IsAlive)
                this.MouseDoubleClick(this.target.Target, args);
        }

        public DoubleClickHelper(FrameworkElement target)
        {
            this.target = new WeakReference(target);

            target.MouseLeftButtonDown += target_MouseLeftButtonDown;
        }

        void target_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            if (DoubleClickHelper.IsDoubleClick(sender, e))
                this.OnMouseDoubleClick(e);
        }
    }

    public static class DoubleClickExtension
    {
        public static DoubleClickHelper GetDoubleClickHelper(DependencyObject obj)
        {
            return (DoubleClickHelper)obj.GetValue(DoubleClickHelperProperty);
        }
        public static void SetDoubleClickHelper(DependencyObject obj, DoubleClickHelper value)
        {
            obj.SetValue(DoubleClickHelperProperty, value);
        }
        public static readonly DependencyProperty DoubleClickHelperProperty =
            DependencyProperty.RegisterAttached("DoubleClickHelper", typeof(DoubleClickHelper), typeof(DoubleClickExtension), new PropertyMetadata(null));

        public static void AddDoubleClickHandler(this FrameworkElement target, MouseButtonEventHandler handler)
        {
            DoubleClickHelper helper = target.GetValue(DoubleClickHelperProperty) as DoubleClickHelper;
            if (helper == null)
            {
                helper = new DoubleClickHelper(target);
                target.SetValue(DoubleClickHelperProperty, helper);
            }

            helper.MouseDoubleClick += handler;
        }

        public static void RemoveDoubleClickHandler(this FrameworkElement target, MouseButtonEventHandler handler)
        {
            DoubleClickHelper helper = target.GetValue(DoubleClickHelperProperty) as DoubleClickHelper;
            if (helper == null) return;

            helper.MouseDoubleClick -= handler;
            if(!helper.HasHandlers)
                target.SetValue(DoubleClickHelperProperty, null);           

        }
    }
 }

答案 4 :(得分：0)

Silverlight 5中有一种更简单的方法，它支持MouseButtonEventArgs.ClickCount。因此，您可以附加一个普通的MouseLeftButtonDown处理程序，并检查：

private void OnMouseLeftButtonDown(object sender, MouseButtonEventArgs args)
{
    if (args.ClickCount == 1)
        return;

    // handle double-click
}

答案 5 :(得分：-1)

这是我为控件实现的类，以及下面的第二个派生类，用于树视图（Silverlight Toolkit）。只需使用您要检查双击的控件实例化它，并为DoubleClicked事件添加处理程序。它使用计时器来尝试模拟双击事件。如果您认为它会更好地工作，您可以更改延迟。

Public Class DoubleClickHelper
Public Event DoubleClicked(ByVal sender As FrameworkElement)
Private WithEvents UI As FrameworkElement

Sub New(ByRef UI As FrameworkElement)
    Me.UI = UI
    UI.AddHandler(UIElement.MouseLeftButtonDownEvent, New MouseButtonEventHandler(AddressOf UI_MouseLeftButtonDown), True)
    InitTimer()
End Sub

Public Delay As Single = 0.2
Private _dblclick As Boolean = False
Private _timer As New System.Windows.Threading.DispatcherTimer()
Protected Property DoubleClick() As Boolean
    Get
        Return _dblclick
    End Get
    Set(ByVal value As Boolean)
        _dblclick = value
        InitTimer()
    End Set
End Property

Private Sub InitTimer()
    RemoveHandler _timer.Tick, AddressOf timer_Tick
    _timer.Stop()
    _timer = New System.Windows.Threading.DispatcherTimer()
    _timer.Interval = TimeSpan.FromSeconds(Delay)
    AddHandler _timer.Tick, AddressOf timer_Tick
    _timer.Start()
End Sub
Protected Overridable Sub timer_Tick(ByVal sender As Object, ByVal e As EventArgs)
    DoubleClick = False
End Sub

Protected Overridable Sub UI_MouseLeftButtonDown(ByVal sender As Object, ByVal e As System.Windows.Input.MouseButtonEventArgs) Handles UI.MouseLeftButtonDown
    If DoubleClick Then
        HandleDoubleClick(sender)
    Else
        HandleFirstClick(sender)
    End If
End Sub

Protected Overridable Sub HandleDoubleClick(ByVal sender As FrameworkElement)
    RaiseEvent DoubleClicked(sender)
End Sub

Protected Overridable Sub HandleFirstClick(ByVal sender As FrameworkElement)
    DoubleClick = True
End Sub

结束班

Public Class TreeViewItemDoubleClickHelper
Inherits DoubleClickHelper

Private SameSelection As Boolean = False
Private WithEvents TreeView As TreeView = Nothing

Public Sub New(ByVal TreeView As TreeView)
    MyBase.New(TreeView)
    Me.TreeView = TreeView
End Sub

'This event happens after MouseLeftButtonDown
Private Sub TreeView_SelectedItemChanged(ByVal sender As Object, ByVal e As System.Windows.RoutedPropertyChangedEventArgs(Of Object)) Handles TreeView.SelectedItemChanged
    SameSelection = e.OldValue Is e.NewValue
End Sub

Protected Overrides Sub UI_MouseLeftButtonDown(ByVal sender As Object, ByVal e As System.Windows.Input.MouseButtonEventArgs)
    'MyBase.UI_MouseLeftButtonDown(sender, e)
    If DoubleClick Or SameSelection Then
        HandleDoubleClick(sender)
        SameSelection = False
        DoubleClick = False
    Else
        HandleFirstClick(sender)
    End If
End Sub

结束班

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