*C#(WPF)--矩阵拖动和矩阵动画（拖动展开，不足动画效果）

OStack程序员社区-中国程序员成长平台 › 门户 › 编程› C++›C++教程

原作者: [db:作者] 来自: [db:来源] 收藏邀请

最近在研发新的项目，遇到了一个桌面模式下的难点--展开动画。之前动画这方面没做过，也许很多人开始做的时候也会遇到相关问题，因此我把几个重点及实际效果图总结展示出来：

我的开发环境是在VS2017下进行的，这个工具条主要功能是：一个工具条，可进行拖拉。可进行拖拉展开，可在拖动之后不足展开并反向继续展开剩下的部分；

一、【拖动】拖动的核心代码是通过矩阵进行定位和拖动的，定位是以父容器为模板的。以下是核心代码（及效果图）：

 1         /// <summary>
 2         ///  这里TitleBar代指最顶上的操作Bar
 3         ///  桌面模式下默认展开工具栏-动画
 4         /// </summary>
 5         private void DesktopToolWindowClick()
 6         {
 7 
 8 
 9             //添加行为
10             var behaviors = System.Windows.Interactivity.Interaction.GetBehaviors(this);
11             behaviors.Clear();
12 
13             behaviors = System.Windows.Interactivity.Interaction.GetBehaviors(this);
14             behaviors.Clear();
15 
16 
17             //添加拖拉事件
18             this._OnMouse = new MoveInContainerBehavior(MoveInContainerBehavior.MoveModes.Free, new Rect(0, 0, WindowsWidth, WindowsHeight));
19             behaviors.Add(this._OnMouse);
20         }
21 
22         /// <summary>
23         /// 加载用户控件的时候订阅事件
24         /// </summary>
25         private void _OnRegisterUserControl()
26         {
27 
28             //订阅鼠标按下控件的事件;
29             _OnMouse.MouseLeftButtonDown += new MoveInContainerBehavior.MouseLeftButtonDownEventHandler(_OnMouseDownEvent);
30             //订阅鼠标拖动控件的事件;
31             _OnMouse.MouseMove += new MoveInContainerBehavior.MouseMoveEventHandler(_OnMouseMoveEvent);
32             //订阅鼠标释放控件的事件;
33             _OnMouse.MouseLeftButtonUp += new MoveInContainerBehavior.MouseLeftButtonUpEventHandler(_OnMouseReleseEvent);
34 
35         }
36 
37         /// <summary>
38         /// 用该事件控制弹窗位置
39         /// </summary>
40         /// <param name="sender"></param>
41         /// <param name="e"></param>
42         private void _ToolBar_Opened(object sender, EventArgs e)
43         {
44             //计算出控件移动的距离
45             var Windows_Lengh = _UserControl_XEnd + this.PopMenu.ActualWidth;
46             if (this._UserControl.ActualWidth + Windows_Lengh >= WindowsWidth)
47             {
48                 this._ToolBar.Placement = System.Windows.Controls.Primitives.PlacementMode.Left;
49                 this._ToolBar.HorizontalOffset = -5;
50             }
51             else
52             {
53                 this._ToolBar.Placement = System.Windows.Controls.Primitives.PlacementMode.Right;
54                 this._ToolBar.HorizontalOffset = 5;
55             }
56         }

二、【拖拉改变样式】通过样式库调用可以在动画开始的时候就更换主题样式通过backup更改样式而不是UI直接改变，以下是核心代码（及效果图）：

 1         #region 更改样式为【展开时候的样式】
 2             this._GridMain.Margin = new Thickness(0, -46, 0, 0);
 3             this._GridRowsF.Height = new GridLength(47);
 4             this.TitleBar.Background = new SolidColorBrush((Color)ColorConverter.ConvertFromString("#4a94ff"));
 5             this.TitleBar.Opacity = 1;
 6             this.TitleBar.Margin = new Thickness(-7, -3, -7, 0);
 7             this.Circle_Bar.Stroke = Brushes.White;
 8             this.Circle_Bar.Margin = new Thickness(0, -3, 0, 0);
 9             this._UserControl.Style = this.FindResource("Style.UserControl.PresentationMode.Desktop.Expand.UserControlStyles") as Style;
10             #endregion

三、【拖拉展开-边缘充足】进行一个动画那就是直接按照自定义的动画时间进行展开，以下是核心代码（及效果图）使用GridLengthAnimation动画类自行百度，下面是经过二次编译的类调用方法：

 1             #region 尝试展开工具条--向下展开
 2             GridLengthAnimation ExpandAnimate = new GridLengthAnimation();
 3             ExpandAnimate.From = new GridLength(0, GridUnitType.Pixel);
 4             ExpandAnimate.To = new GridLength(_GridRowsSLength, GridUnitType.Pixel);
 5             ExpandAnimate.Duration = TimeSpan.FromSeconds(0.3);
 6             ExpandAnimate.AutoReverse = false;
 7             this._GridMain.RowDefinitions[1].BeginAnimation(RowDefinition.HeightProperty, ExpandAnimate);
 8 
 9 
10 
11 
12             #endregion

四、【拖拉展开-边缘不足】进行两个动画 1-先展开到边缘动画 2-再反弹反方向展开动画，以下是核心代码（及效果图）：

 1  #region 先往下展开，展开结束之后再启用往上增加动画
 2             GridLengthAnimation ExpandAnimate = new GridLengthAnimation();
 3             ExpandAnimate.From = new GridLength(0, GridUnitType.Pixel);
 4             ExpandAnimate.To = new GridLength(WindowsHeight - ParentPoint.Y - 68, GridUnitType.Pixel);
 5             ExpandAnimate.Duration = TimeSpan.FromSeconds(0.15);
 6             ExpandAnimate.AutoReverse = false;
 7             ExpandAnimate.Completed += StartMatrixExpandAnimate_Completed;
 8             this._GridMain.RowDefinitions[1].BeginAnimation(RowDefinition.HeightProperty, ExpandAnimate);
 9 
10             #endregion
11 
12  /// <summary>
13         /// 当展开动画结束之后开始执行反向动画
14         /// </summary>
15         /// <param name="sender"></param>
16         /// <param name="e"></param>
17         private void StartMatrixExpandAnimate_Completed(object sender, EventArgs e)
18         {
19             //删除动画
20             this._GridMain.RowDefinitions[1].BeginAnimation(RowDefinition.HeightProperty, null);
21 
22             #region 向上移动动画
23             // 1-向上移动
24             Storyboard storyboard = new Storyboard();
25             storyboard.FillBehavior = FillBehavior.Stop;
26             MatrixTransform matrixTransformOfOwner = this.RenderTransform as MatrixTransform;
27             if (matrixTransformOfOwner == null)
28             {
29                 matrixTransformOfOwner = new MatrixTransform(this.RenderTransform.Value);
30                 this.RenderTransform = matrixTransformOfOwner;
31             }
32             this._oldTransform = this.RenderTransform;
33             Matrix matrixOfOwner = this.RenderTransform.Value;
34             Matrix fromMatrix = matrixOfOwner;
35             Matrix toMatrix = new Matrix();
36             toMatrix.OffsetX = ParentPoint.X;
37             toMatrix.OffsetY = WindowsHeight - _GridRowsSLength - 68;
38 
39             MatrixAnimation matrixAnimation = new MatrixAnimation(fromMatrix, toMatrix, TimeSpan.FromSeconds(0.3));
40             matrixAnimation.Completed += (s, ex) => { UnlockProperty(toMatrix); };
41 
42             Storyboard.SetTarget(matrixAnimation, this);
43             Storyboard.SetTargetProperty(matrixAnimation, new PropertyPath("(UIElement.RenderTransform).(MatrixTransform.Matrix)"));
44 
45             storyboard.Children.Add(matrixAnimation);
46             storyboard.Begin();
47 
48             #endregion
49 
50 
51 
52         }