我在listBox中有图像集合
<ListBox Name="lb" HorizontalAlignment="Center" VerticalAlignment="Center" Grid.Row="0" ScrollViewer.HorizontalScrollBarVisibility="Auto"
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding}" >
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Center" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="Visibility" Value="Collapsed" />
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Visibility" Value="Visible"/>
</Trigger>
</Style.Triggers>
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<Image Source="{Binding}" Width="150" Height="100"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
只有一个可见项目。
如何滑动或滚动图像？或者如果我将光标拖到左侧或右侧的可见图像上，如何管理应该选择的项目？
答案 0 :(得分：0)
我在过去的项目中实现了类似的东西
以下是一些代码。它或多或少会按预期工作，但您可以随时根据需要进行调整
这实现了通过滚动到所需位置来使所选项目进行查看的行为，并实现向左或向右滑动项目/图像。
列表框/ ItemsControl （绑定不重要，但对动态项很有用）
<ItemsControl ItemsSource="{Binding}">
<i:Interaction.Behaviors>
<behavior:BringSelectionToViewBehavior SelectedItem="{Binding CurrentPage,Mode=TwoWay}" />
</i:Interaction.Behaviors>
<ItemsControl.Template>
<ControlTemplate TargetType="{x:Type ItemsControl}">
<ScrollViewer HorizontalScrollBarVisibility="Hidden"
VerticalScrollBarVisibility="Hidden">
<ItemsPresenter />
</ScrollViewer>
</ControlTemplate>
</ItemsControl.Template>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"
IsItemsHost="True" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
<强> BringSelectionToViewBehavior.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Animation;
using System.Windows.Media;
using System.Windows.Threading;
using System.Windows.Input;
using Microsoft.Expression.Interactivity;
namespace MyProject.Behaviors
{
public class BringSelectionToViewBehavior : Behavior<ItemsControl>
{
Queue<Point> velocityPoints = new Queue<Point>(4);
Point PreviousPoint { get; set; }
DispatcherTimer valocityTimer = new DispatcherTimer();
public object SelectedItem
{
get { return GetValue(SelectedItemProperty); }
set { SetValue(SelectedItemProperty, value); }
}
// Using a DependencyProperty as the backing store for SelectedItem. This enables animation, styling, binding, etc...
public static readonly DependencyProperty SelectedItemProperty =
DependencyProperty.Register("SelectedItem", typeof(object), typeof(BringSelectionToViewBehavior), new UIPropertyMetadata(null, OnSelectedItemChanged));
protected override void OnAttached()
{
base.OnAttached();
AssociatedObject.AddHandler(ItemsControl.SizeChangedEvent, (SizeChangedEventHandler)OnWidthChanged);
AssociatedObject.LayoutUpdated += new EventHandler(AssociatedObject_LayoutUpdated);
AssociatedObject.ReleaseMouseCapture();
valocityTimer.Interval = TimeSpan.FromMilliseconds(20);
valocityTimer.Tick += valocityTimer_Tick;
}
ItemsPresenter itemsPresenter;
void AssociatedObject_LayoutUpdated(object sender, EventArgs e)
{
if (itemsPresenter == null)
{
itemsPresenter = AssociatedObject.FindChildrenByType<ItemsPresenter>().ToList().First();
AssociatedObject.MouseMove += AssociatedObject_MouseMove;
itemsPresenter.AddHandler(UIElement.MouseLeftButtonDownEvent, new MouseButtonEventHandler(ItemPresenter_MouseLeftButtonDown), false);
itemsPresenter.AddHandler(UIElement.MouseLeftButtonUpEvent, new MouseButtonEventHandler(ItemPresenter_MouseLeftButtonUp), true);
}
}
public void OnWidthChanged(object s, SizeChangedEventArgs e)
{
Dispatcher.BeginInvoke((Action<ItemsControl, object>)QueueAnimation, DispatcherPriority.Render, new[] { AssociatedObject, SelectedItem });
}
private void QueueAnimation(ItemsControl control, object item)
{
BringItemToView(item);
}
public static void OnSelectedItemChanged(DependencyObject s, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue == null)
return;
BringSelectionToViewBehavior behavior = s as BringSelectionToViewBehavior;
if (!behavior.valocityOverride.HasValue)
behavior.BringItemToView(e.NewValue);
}
private void BringItemToView(object item, EasingMode easeMode = EasingMode.EaseInOut)
{
if (item == null || AssociatedObject == null)
return;
FrameworkElement element = AssociatedObject.ItemContainerGenerator.ContainerFromItem(item) as FrameworkElement;
BringElementToView(element, easeMode);
}
private void BringElementToView(FrameworkElement element, EasingMode easeMode)
{
if (element == null)
return;
ScrollViewer scrollViewer = element.FindAncestorByType<ScrollViewer>();
if (scrollViewer != null)
{
Point relativePoint = element.TransformToAncestor(scrollViewer).Transform(new Point(0, 0));
ScrollToPosition(scrollViewer, relativePoint.X, relativePoint.Y, easeMode);
}
else
{
element.BringIntoView();
}
}
private void ScrollToPosition(ScrollViewer viewer, double x, double y, EasingMode easeMode)
{
Storyboard sb = new Storyboard();
if (y != 0)
{
DoubleAnimation vertAnim = new DoubleAnimation();
//if (applyEase)
vertAnim.EasingFunction = new CubicEase() { EasingMode = easeMode };
vertAnim.From = viewer.VerticalOffset;
vertAnim.By = y;
vertAnim.Duration = GetAnimationDuration(y);
sb.Children.Add(vertAnim);
Storyboard.SetTarget(vertAnim, viewer);
Storyboard.SetTargetProperty(vertAnim, new PropertyPath(BringSelectionToViewBehavior.VerticalOffsetProperty));
}
if (x != 0)
{
DoubleAnimation horzAnim = new DoubleAnimation();
horzAnim.From = viewer.HorizontalOffset;
horzAnim.By = x;
horzAnim.Duration = GetAnimationDuration(x);
horzAnim.EasingFunction = new CubicEase() { EasingMode = easeMode };
sb.Children.Add(horzAnim);
Storyboard.SetTarget(horzAnim, viewer);
Storyboard.SetTargetProperty(horzAnim, new PropertyPath(BringSelectionToViewBehavior.HorizontalOffsetProperty));
}
//overrideDuretion = false;
sb.Completed += new EventHandler(sb_Completed);
sb.Begin();
}
void sb_Completed(object sender, EventArgs e)
{
((sender as ClockGroup).Timeline as Storyboard).Remove();
valocityOverride = null;
}
double? valocityOverride;
private Duration GetAnimationDuration(double distanceToTravel)
{
double animTime = Math.Abs(distanceToTravel) * .7;
if (valocityOverride.HasValue && valocityOverride > 50)
{
animTime = Math.Abs(distanceToTravel) * (valocityOverride.Value / 1000);
}
if (animTime > 1500)
animTime = 1500;
if (animTime < 250)
animTime = 250;
return new Duration(TimeSpan.FromMilliseconds(animTime));
}
public static double GetVerticalOffset(DependencyObject obj)
{
return (double)obj.GetValue(VerticalOffsetProperty);
}
public static void SetVerticalOffset(DependencyObject obj, double value)
{
obj.SetValue(VerticalOffsetProperty, value);
}
// Using a DependencyProperty as the backing store for VerticalOffset. This enables animation, styling, binding, etc...
public static readonly DependencyProperty VerticalOffsetProperty =
DependencyProperty.RegisterAttached("VerticalOffset", typeof(double), typeof(BringSelectionToViewBehavior), new PropertyMetadata(new PropertyChangedCallback(OnVerticalChanged)));
public static double GetHorizontalOffset(DependencyObject obj)
{
return (double)obj.GetValue(HorizontalOffsetProperty);
}
public static void SetHorizontalOffset(DependencyObject obj, double value)
{
obj.SetValue(HorizontalOffsetProperty, value);
}
// Using a DependencyProperty as the backing store for HorizontalOffset. This enables animation, styling, binding, etc...
public static readonly DependencyProperty HorizontalOffsetProperty =
DependencyProperty.RegisterAttached("HorizontalOffset", typeof(double), typeof(BringSelectionToViewBehavior), new PropertyMetadata(new PropertyChangedCallback(OnHorizontalChanged)));
private static void OnVerticalChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ScrollViewer viewer = d as ScrollViewer;
viewer.ScrollToVerticalOffset((double)e.NewValue);
}
private static void OnHorizontalChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
ScrollViewer viewer = d as ScrollViewer;
viewer.ScrollToHorizontalOffset((double)e.NewValue);
}
void valocityTimer_Tick(object sender, EventArgs e)
{
Point currentPoint = Mouse.GetPosition(AssociatedObject);
velocityPoints.Enqueue(currentPoint);
if (velocityPoints.Count > 4)
velocityPoints.Dequeue();
}
private void AssociatedObject_MouseMove(object sender, MouseEventArgs e)
{
if (itemsPresenter.IsMouseCaptured)
{
Point CurrentPoint = e.GetPosition(AssociatedObject);
Vector offset = PreviousPoint - CurrentPoint;
PreviousPoint = CurrentPoint;
if (offset.X != 0)
{
Viewer.ScrollToHorizontalOffset(Viewer.HorizontalOffset + offset.X);
}
}
}
public ScrollViewer Viewer { get; set; }
/// <summary>
/// Handles the MouseLeftButtonDown event of the ItemPresenter control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="System.Windows.Input.MouseButtonEventArgs"/> instance containing the event data.</param>
private void ItemPresenter_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
//Viewer.ApplyAnimationClock(BringSelectionToViewBehavior.HorizontalOffsetProperty, null);
Border bd = (e.OriginalSource as FrameworkElement).FindAncestorByType<Border>();
if (bd == null || (bd != null && bd.Name != "GripBarElement"))
{
Viewer = AssociatedObject.FindChildrenByType<ScrollViewer>().ToList().First();
PreviousPoint = e.GetPosition(AssociatedObject);
itemsPresenter.CaptureMouse();
velocityPoints.Clear();
valocityTimer.Start();
}
}
private double CalculateMouseSpeed()
{
if (velocityPoints.Count > 1)
{
Point first = velocityPoints.Dequeue();
return velocityPoints.Aggregate<Point, Point, double>(first, (s, pt) => new Point(s.X, pt.X), pt => pt.X - pt.Y);
}
return 0;
}
/// <summary>
/// Handles the MouseLeftButtonUp event of the ItemPresenter control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="System.Windows.Input.MouseButtonEventArgs"/> instance containing the event data.</param>
private void ItemPresenter_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
if (itemsPresenter.IsMouseCaptured)
{
if (Viewer == null)
return;
valocityTimer.Stop();
itemsPresenter.ReleaseMouseCapture();
double MouseSpeed = CalculateMouseSpeed() / 3;
double newtotal = 5 * MouseSpeed;
double newOffset = Viewer.HorizontalOffset + newtotal;
double maxOffset = itemsPresenter.ActualWidth - (itemsPresenter.ActualWidth / AssociatedObject.Items.Count);
if (newOffset < 0)
{
newtotal += 0 - newOffset;
}
else if (newOffset > maxOffset)
{
newtotal -= newOffset - maxOffset;
}
newOffset = Viewer.HorizontalOffset + newtotal;
int newIndex = (int)System.Math.Round(newOffset / (itemsPresenter.ActualWidth / AssociatedObject.Items.Count));
object objToSet = AssociatedObject.ItemsSource.OfType<object>().ElementAt(newIndex);
if (objToSet != null)
{
valocityOverride = MouseSpeed;
if (!object.Equals(SelectedItem, objToSet))
SelectedItem = objToSet;
BringItemToView(objToSet, EasingMode.EaseOut);
}
}
}
}
}
试一试，看看这是否可以解决您的问题。