WPF实现简单的跑马灯效果

技术  /  管理员 发布于 7年前   436

最近项目上要用到跑马灯的效果，和网上不太相同的是，网上大部分都是连续的，而我们要求的是不连续的。

也就是是，界面上就展示4项（展示项数可变），如果有7项要展示的话，则不断的在4个空格里左跳，当然，衔接上效果不是很好看。

然后，需要支持点击以后进行移除掉不再显示的内容。

效果如下：

思路大致如下：

1、最外层用一个ViewBox，为了可以填充调用此控件的地方，这样可以方便自动拉伸

复制代码 代码如下:

<Viewbox x:Name="viewbox_main" Height="{Binding Path=ActualHeight}" Width="{Binding Path=ActualWidth}" MouseLeave="grid_main_MouseLeave" MouseMove="grid_main_MouseMove"  HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Stretch="Fill"/>

2、定义三个变量，一个是Count值，是为了设定要展示的UserControl的个数的，例如默认是4个，如效果图，当然，设置成5的话，就是5个了；一个List<Grid>是为了放入展示控件的列表，一个List<UserControl>是用来放所有要用于跑马灯里的控件的。

3、设置一个Canvas，放入到最外层的Viewbox中，用于跑马灯时候用（这也是常用的跑马灯控件Canvas）

//给Canvas设置一些属性 canvas_board.VerticalAlignment = VerticalAlignment.Stretch; canvas_board.HorizontalAlignment = HorizontalAlignment.Stretch;canvas_board.Width = this.viewbox_main.ActualWidth;canvas_board.Height = this.viewbox_main.ActualHeight;canvas_board.ClipToBounds = true;//用viewbox可以支持拉伸this.viewbox_main.Child = canvas_board;

4、将要循环的Grid放入到Canvas里，这里的Grid的个数，要比展示的个数大一个，也就是Count+1个值，因为滚动的时候，其实是在最外面有一个的，这样保证了循环的走动。至于两个控件之间的Margin这个就是要设置Grid的了，到时候控件是直接扔进Grid里的

//循环将Grid加入到要展示的列表里for (int i = 0; i < Uc_Count + 1; i++){ Grid grid = new Grid(); grid.Width = canvas_board.Width / Uc_Count - 10; grid.Height = canvas_board.Height - 10; grid.Margin = new Thickness(5); this.canvas_board.Children.Add(grid); grid.SetValue(Canvas.TopProperty, 0.0); grid.SetValue(Canvas.LeftProperty, i * (grid.Width + 10)); UcListForShow.Add(grid);}

5、给每个Grid增加一个动画效果，就是向左移动的效果

for (int i = 0; i < UcListForShow.Count; i++){ //设置滚动时候的效果 DoubleAnimationUsingKeyFrames daukf_uc = new DoubleAnimationUsingKeyFrames(); LinearDoubleKeyFrame k1_uc = new LinearDoubleKeyFrame(i * (UcListForShow[i].Width + 10), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2))); LinearDoubleKeyFrame k2_uc = new LinearDoubleKeyFrame((i - 1) * (UcListForShow[i].Width + 10), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2.5))); daukf_uc.KeyFrames.Add(k1_uc); daukf_uc.KeyFrames.Add(k2_uc); storyboard_imgs.Children.Add(daukf_uc); Storyboard.SetTarget(daukf_uc, UcListForShow[i]); Storyboard.SetTargetProperty(daukf_uc, new PropertyPath("(Canvas.Left)"));}

6、滚动的时候，要计算UserControl到底是添加到了哪个Grid里面，也就是哪个控件作为了第一位。

我们设置一个索引值scroll_index，默认的时候，scroll_index=0，这是初始的状态，当滚动起来以后，scroll_index = scroll_index + 1 - Uc_Count;

然后，判断，循环的时候，是否是展示列表的末尾了，如果是的话，则要填充的控件是scroll_index %UcListSum.Count（滚动索引，对总数直接取余数），如果不是的话则是scroll_index++ % UcListSum.Count（滚动索引++，对总数直接取余数）

scroll_index = scroll_index + 1 - Uc_Count;for (int i = 0; i < UcListForShow.Count; i++){ UcListForShow[i].SetValue(Canvas.LeftProperty, i * (UcListForShow[i].Width + 10)); UserControl uc; if (i == UcListForShow.Count - 1) {  uc = UcListSum[scroll_index % UcListSum.Count]; } else {  uc = UcListSum[scroll_index++ % UcListSum.Count]; } if (uc.Parent != null) {  (uc.Parent as Grid).Children.Clear();//将Usercontrol从原来的里面移除掉，要不然会抛错，Usercontrol已属于另一个控件 } UcListForShow[i].Children.Clear(); UcListForShow[i].Children.Add(uc); //将隐藏按钮加入到Grid里 Button btn = new Button(); btn.Style = (dictionary["hidenStyle"] as Style);//从样式文件里读取到Button的样式 btn.Tag = UcListForShow[i].Children;//给Tag赋值，这样方便查找 btn.Click += Btn_Click;//注册隐藏事件 UcListForShow[i].Children.Add(btn);}

代码中，需要注意的是(uc.Parent as Grid).Children.Clear()，如果不移除的话，则会提示，已经属于另一个，所以，要从parent里面移除掉。

7、Button的隐藏事件，当Button点击以后，则要进行隐藏，其实也就是将总数里面，减除掉不再显示的那一项

private void Btn_Click(object sender, RoutedEventArgs e){ if ((sender as Button).Tag != null) {  UcListSum.Remove((((sender as Button).Tag as UIElementCollection)[0] as UserControl)); } if (UcListSum.Count == Uc_Count)//当列表数和要展示的数目相同的时候，就停止掉动画效果 {  storyboard_imgs.Completed -= Storyboard_imgs_Completed;  storyboard_imgs.Stop();  for (int i = 0; i < Uc_Count; i++)  {   UcListForShow[i].Children.Clear();   if (UcListSum[i].Parent != null)   {    (UcListSum[i].Parent as Grid).Children.Clear();   }   UcListForShow[i].Children.Add(UcListSum[i]);  }  return; }}

所有代码如下：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Media.Imaging;using System.Windows.Navigation;using System.Windows.Shapes;namespace MarqueeUserControl{ /// <summary> /// MarqueeUC.xaml 的交互逻辑 /// </summary> public partial class MarqueeUC : UserControl {  ResourceDictionary dictionary;  public MarqueeUC()  {   InitializeComponent();   //读取样式文件   dictionary = new ResourceDictionary { Source = new Uri("/MarqueeUserControl;component/MarqueeUserControlDictionary.xaml", UriKind.Relative) };  }  #region 属性  private int _uc_Count = 0;  /// <summary>  /// 用来展示几个  /// </summary>  public int Uc_Count  {   get   {    return _uc_Count;   }   set   {    _uc_Count = value;   }  }  private List<Grid> _ucListForShow = new List<Grid>();  /// <summary>  /// 用来展示的控件列表  /// </summary>  private List<Grid> UcListForShow  {   get   {    return _ucListForShow;   }   set   {    _ucListForShow = value;   }  }  private List<UserControl> _ucListSum = new List<UserControl>();  /// <summary>  /// 要添加的控件的列表  /// </summary>  public List<UserControl> UcListSum  {   get   {    return _ucListSum;   }   set   {    _ucListSum = value;   }  }  #endregion  Canvas canvas_board = new Canvas();  Storyboard storyboard_imgs = new Storyboard();  int scroll_index = 0;//滚动索引  double scroll_width;//滚动宽度  void GridLayout()  {   if (Uc_Count == 0)//如果这个值没有赋值的话，则默认显示四个   {    Uc_Count = 4;   }   //给Canvas设置一些属性   canvas_board.VerticalAlignment = VerticalAlignment.Stretch;   canvas_board.HorizontalAlignment = HorizontalAlignment.Stretch;   canvas_board.Width = this.viewbox_main.ActualWidth;   canvas_board.Height = this.viewbox_main.ActualHeight;   canvas_board.ClipToBounds = true;   //用viewbox可以支持拉伸   this.viewbox_main.Child = canvas_board;   //循环将Grid加入到要展示的列表里   for (int i = 0; i < Uc_Count + 1; i++)   {    Grid grid = new Grid();    grid.Width = canvas_board.Width / Uc_Count - 10;    grid.Height = canvas_board.Height - 10;    grid.Margin = new Thickness(5);    this.canvas_board.Children.Add(grid);    grid.SetValue(Canvas.TopProperty, 0.0);    grid.SetValue(Canvas.LeftProperty, i * (grid.Width + 10));    UcListForShow.Add(grid);   }  }  void StoryLoad()  {   for (int i = 0; i < UcListForShow.Count; i++)   {//设置滚动时候的效果    DoubleAnimationUsingKeyFrames daukf_uc = new DoubleAnimationUsingKeyFrames();    LinearDoubleKeyFrame k1_uc = new LinearDoubleKeyFrame(i * (UcListForShow[i].Width + 10), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2)));    LinearDoubleKeyFrame k2_uc = new LinearDoubleKeyFrame((i - 1) * (UcListForShow[i].Width + 10), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2.5)));    daukf_uc.KeyFrames.Add(k1_uc);    daukf_uc.KeyFrames.Add(k2_uc);    storyboard_imgs.Children.Add(daukf_uc);    Storyboard.SetTarget(daukf_uc, UcListForShow[i]);    Storyboard.SetTargetProperty(daukf_uc, new PropertyPath("(Canvas.Left)"));   }   storyboard_imgs.FillBehavior = FillBehavior.Stop;   storyboard_imgs.Completed += Storyboard_imgs_Completed;   storyboard_imgs.Begin();  }  private void Storyboard_imgs_Completed(object sender, EventArgs e)  {   scroll_index = scroll_index + 1 - Uc_Count;   for (int i = 0; i < UcListForShow.Count; i++)   {    UcListForShow[i].SetValue(Canvas.LeftProperty, i * (UcListForShow[i].Width + 10));    UserControl uc;    if (i == UcListForShow.Count - 1)    {     uc = UcListSum[scroll_index % UcListSum.Count];    }    else    {     uc = UcListSum[scroll_index++ % UcListSum.Count];    }    if (uc.Parent != null)    {     (uc.Parent as Grid).Children.Clear();//将Usercontrol从原来的里面移除掉，要不然会抛错，Usercontrol已属于另一个控件    }    UcListForShow[i].Children.Clear();    UcListForShow[i].Children.Add(uc);    //将隐藏按钮加入到Grid里    Button btn = new Button();    btn.Style = (dictionary["hidenStyle"] as Style);//从样式文件里读取到Button的样式    btn.Tag = UcListForShow[i].Children;//给Tag赋值，这样方便查找    btn.Click += Btn_Click;//注册隐藏事件    UcListForShow[i].Children.Add(btn);   }   storyboard_imgs.Begin();  }  private void Btn_Click(object sender, RoutedEventArgs e)  {   if ((sender as Button).Tag != null)   {    UcListSum.Remove((((sender as Button).Tag as UIElementCollection)[0] as UserControl));   }   if (UcListSum.Count == Uc_Count)//当列表数和要展示的数目相同的时候，就停止掉动画效果   {    storyboard_imgs.Completed -= Storyboard_imgs_Completed;    storyboard_imgs.Stop();    for (int i = 0; i < Uc_Count; i++)    {     UcListForShow[i].Children.Clear();     if (UcListSum[i].Parent != null)     {      (UcListSum[i].Parent as Grid).Children.Clear();     }     UcListForShow[i].Children.Add(UcListSum[i]);    }    return;   }  }  public void StartMar()  {   GridLayout();   scroll_width = this.canvas_board.Width;   for (int i = 0; i < UcListForShow.Count; i++)   {    UserControl uc;    if (i == UcListForShow.Count - 1)    {     uc = UcListSum[scroll_index % UcListSum.Count];    }    else    {     uc = UcListSum[scroll_index++ % UcListSum.Count];    }    if (uc.Parent != null)    {     (uc.Parent as Grid).Children.Clear();    }    UcListForShow[i].Children.Clear();    UcListForShow[i].Children.Add(uc);   }   StoryLoad();  }  private void grid_main_MouseLeave(object sender, MouseEventArgs e)  {   if (storyboard_imgs.GetCurrentState() == ClockState.Stopped)//如果是停止的状态，则直接返回，不再起作用   {    return;   }   if (storyboard_imgs.GetIsPaused() == true)//如果是暂停状态的话，则开始   {    storyboard_imgs.Begin();   }  }  private void grid_main_MouseMove(object sender, MouseEventArgs e)  {   if (storyboard_imgs.GetIsPaused() == false)   {    storyboard_imgs.Pause();   }  } }}

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:local="clr-namespace:MarqueeUserControl"> <Style TargetType="Button" x:Key="hidenStyle">  <Setter Property="Background" Value="Transparent"/>  <Setter Property="HorizontalAlignment" Value="Center"/>  <Setter Property="VerticalAlignment" Value="Center"/>  <Setter Property="Width" Value="25"/>  <Setter Property="Height" Value="25"/>  <Setter Property="BorderBrush" Value="Transparent"/>  <Setter Property="BorderThickness" Value="0"/>  <Setter Property="Template"><!--把Image放到Template里作为Content显示，如果是单独给Content设置图片的话，则只有一个按钮显示图片，其他的不显示-->   <Setter.Value>    <ControlTemplate TargetType="{x:Type Button}">     <Border>      <Image Source="hiden.png"/>     </Border>    </ControlTemplate>   </Setter.Value>  </Setter> </Style></ResourceDictionary>

没有解决的问题

想给Button增加鼠标悬停的时候，显示，移除的时候隐藏，但是发现不好使，原因是当MouseOver上去的时候，虽然Visibility的值变了，但是只有到下一次的时候，Button的值才被附上，而此时，已经MouseLeave了，请哪位大神指导一下，看看这个显示和隐藏怎么做。

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