WPF实现背景灯光随鼠标闪动效果

本文实例为大家分享了wpf实现背景灯光随鼠标闪动的具体代码，供大家参考，具体内容如下

实现效果如下：

思路：将容器分割成组合三角形path，鼠标移动时更新每个三角形的填充颜色。

步骤：

1、窗体xaml

只需放置一个canvas。

<canvas x:name="container" width="400" height="400"></canvas>

2、交互逻辑

/// <summary>
/// mainwindow.xaml 的交互逻辑
/// </summary>
 public partial class mainwindow : window
 {
  private point lastmouseposition = new point(0, 0);//鼠标位置
  private int trianglelength = 100;//三角形边长
 
  public mainwindow()
  {
   initializecomponent();
   this.loaded += mainwindow_loaded;
   compositiontarget.rendering += updatetriangle;
   this.container.previewmousemove += updatelastmouseposition;
  }
 
  private void mainwindow_loaded(object sender, routedeventargs e)
  {
   //将长方形容易划分成组合三角形
   int horizontalcount = (int)(this.container.actualwidth / trianglelength);
   int verticalcount = (int)(this.container.actualheight / trianglelength);
   for (int i = 0; i < horizontalcount; i++)
   {
    for (int j = 0; j < verticalcount; j++)
    {
     path trianglepath1 = new path();
     var g1 = new streamgeometry();
     using (streamgeometrycontext context = g1.open())
     {
      context.beginfigure(new point(i * trianglelength, j * trianglelength), true, true);
      context.lineto(new point(i * trianglelength, (j + 1) * trianglelength), true, false);
      context.lineto(new point((i + 1) * trianglelength, (j + 1) * trianglelength), true, false);
     }
     trianglepath1.data = g1;
     trianglepath1.fill = new solidcolorbrush(color.fromargb(255, 247, 18, 65));
     this.container.children.add(trianglepath1);
 
     path trianglepath2 = new path();
     var g2 = new streamgeometry();
     using (streamgeometrycontext context = g2.open())
     {
      context.beginfigure(new point(i * trianglelength, j * trianglelength), true, true);
      context.lineto(new point((i + 1) * trianglelength, j * trianglelength), true, false);
      context.lineto(new point((i + 1) * trianglelength, (j + 1) * trianglelength), true, false);
     }
     trianglepath2.data = g2;
     trianglepath2.fill = new solidcolorbrush(color.fromargb(255, 247, 18, 65));
     this.container.children.add(trianglepath2);
    }
   }
  }
 
  private void updatetriangle(object sender, eventargs e)
  {
   //获取子控件
   list<path> childlist = getchildobjects<path>(this.container);
   for (int i = 0; i < childlist.count; i++)
   {
    for (int j = 1; j < childlist.count; j++)
    {
     string si = childlist[i].data.tostring();
     string si1 = midstrex(si, "m", "l");
     string si2 = midstrex(si, "l", " ");
     string si3 = midstrex(si, " ", "z");
     string sj = childlist[j].data.tostring();
     string sj1 = midstrex(sj, "m", "l");
     string sj2 = midstrex(sj, "l", " ");
     string sj3 = midstrex(sj, " ", "z");
     //左右三角形判断
     if (si1 == sj1 && si3 == sj3)
     {
      double x = childlist[i].data.bounds.x + (1 - math.pow(2, 0.5) / 2) * trianglelength - lastmouseposition.x;
      double y = childlist[i].data.bounds.y + (1 - math.pow(2, 0.5) / 2) * trianglelength - lastmouseposition.y;
      double rradio = 1 - math.pow(x * x + y * y, 0.5) / math.pow(this.container.actualwidth * this.container.actualwidth + this.container.actualheight * this.container.actualheight, 0.5);
      childlist[j].fill = new solidcolorbrush(color.fromargb((byte)(255 * rradio), 247, 18, 65));
      x = childlist[j].data.bounds.topright.x - (1 - math.pow(2, 0.5) / 2) * trianglelength - lastmouseposition.x;
      rradio = 1 - math.pow(x * x + y * y, 0.5) / math.pow(this.container.actualwidth * this.container.actualwidth + this.container.actualheight * this.container.actualheight, 0.5);
      childlist[i].fill = new solidcolorbrush(color.fromargb((byte)(255 * rradio), 247, 18, 65));
      break;
     }
    }
   }
  }
 
  private void updatelastmouseposition(object sender, mouseeventargs e)
  {
   lastmouseposition = e.getposition(this.container);
  }
 
  /// <summary>
  /// 获得所有子控件
  /// </summary>
  private list<t> getchildobjects<t>(system.windows.dependencyobject obj) where t : system.windows.frameworkelement
  {
   system.windows.dependencyobject child = null;
   list<t> childlist = new list<t>();
   for (int i = 0; i < visualtreehelper.getchildrencount(obj); i++)
   {
    child = visualtreehelper.getchild(obj, i);
    if (child is t)
    {
     childlist.add((t)child);
    }
    childlist.addrange(getchildobjects<t>(child));
   }
   return childlist;
  }
 
  /// <summary>
  /// 截取两个指定字符中间的字符串
  /// </summary>
  public static string midstrex(string sourse, string startstr, string endstr)
  {
   string result = string.empty;
   int startindex, endindex;
   try
   {
    startindex = sourse.indexof(startstr);
    if (startindex == -1)
     return result;
    string tmpstr = sourse.substring(startindex + startstr.length);
    endindex = tmpstr.indexof(endstr);
    if (endindex == -1)
     return result;
    result = tmpstr.remove(endindex);
   }
   catch (exception ex)
   {
   }
   return result;
  }
}

说明：当组合三角形过多时，会有明显卡顿，需要优化色彩更新方法。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。