Silverlight 解谜游戏 之十一 鼠标的新衣

       本篇我们将对鼠标指针进行美化，也给它穿上好看点的马甲，对于其样式来源可以选择Image 或Path。可以通过微软的 Expression Design 设计出鼠标指针样式

。

   

先看看鼠标指针换上新装的效果：

 

1. 将鼠标指针图片加入Images 文件夹：

2. 在Interactivity 中创建MouseCursor 文件夹，并在其中加入MouseCursorBehavior、NameResolvedEventArgs、NameResolver 类：

3. 在NameResolver 类中，最关键的就是UpdateObjectFromName 方法，它将CursorName 属性与鼠标指针对象结合起来：

private void UpdateObjectFromName(DependencyObject oldobject)  {     DependencyObject resolvedobject = null;     this.Resolvedobject = null;       if (this.NameScopeReferenceElement != null)     {        if (!IsElementLoaded(this.NameScopeReferenceElement))        {            this.NameScopeReferenceElement.Loaded += 
new RoutedEventHandler(this.OnNameScopeReferenceLoaded);            this.PendingReferenceElementLoad = true;            return;        }        if (!string.IsNullOrEmpty(this.Name))        {            FrameworkElement actualNameScopeReferenceElement = 
this.ActualNameScopeReferenceElement;            if (actualNameScopeReferenceElement != null)            {               resolvedobject = actualNameScopeReferenceElement.FindName(this.Name) 
as DependencyObject;            }        }     }     this.HasAttempedResolve = true;     this.Resolvedobject = resolvedobject;     if (oldobject != this.Object)     {        this.OnObjectChanged(oldobject,this.Object);     }  }

4. 在MouseCursorBehavior 类中，存有CursorName、OffsetX、OffsetY 属性，它们将用于在Blend 中对鼠标指针进行设置：

public static readonly DependencyProperty CursorNameProperty =     DependencyProperty.Register("CursorName",typeof(string),typeof(MouseCursorBehavior),new PropertyMetadata(new PropertyChangedCallback(OnCursorNameChanged)));    public static readonly DependencyProperty OffsetXProperty =    DependencyProperty.Register("OffsetX",typeof(double),null);    public static readonly DependencyProperty OffsetYProperty =    DependencyProperty.Register("OffsetY",null);

以及MouseEnter、MouseLeave、MouseMove 事件：

private void Associatedobject_MouseEnter(object sender,MouseEventArgs e)  {     if (!this.IsCursorNameSet)        return;       FrameworkElement cursor = Cursor as FrameworkElement;     cursor.IsHitTestVisible = false;     cursor.Visibility = Visibility.Visible;       if (CursorStack.Count > 0 && CursorStack.Peek() != cursor)     {        CursorStack.Peek().Visibility = Visibility.Collapsed;     }       if (!CursorStack.Contains(cursor))        CursorStack.Push(cursor);       Associatedobject.Cursor = Cursors.None;       this.Associatedobject.MouseMove += new MouseEventHandler(Associatedobject_MouseMove);  }    private void Associatedobject_MouseLeave(object sender,MouseEventArgs e)  {     if (!this.IsCursorNameSet)        return;       FrameworkElement cursor = Cursor as FrameworkElement;     cursor.Visibility = Visibility.Collapsed;       CursorStack.Pop();       if (CursorStack.Count > 0)     {        CursorStack.Peek().Visibility = Visibility.Visible;     }       this.Associatedobject.MouseMove -= new MouseEventHandler(Associatedobject_MouseMove);     Associatedobject.Cursor = null;  }    private void Associatedobject_MouseMove(object sender,MouseEventArgs e)  {     if (!this.IsCursorNameSet)        return;       FrameworkElement cursor = Cursor as FrameworkElement;       Point mousePosition = e.GetPosition(null);     cursor.Margin = new Thickness(mousePosition.X + OffsetX,mousePosition.Y + OffsetY,0);    }

5. 添加好上面三个类并重新编译后，我们回到Blend 中，为UserControl 添加新的Behavior->MouseCursorBehavior：

6. 在LayoutRoot 中添加鼠标指针图片，命名为cursorArrow：

将其放在GameScreen 上方，Left 设为0，Top 设为-50：

7. 选择刚刚添加的MouseCursorBehavior 将CursorName 设为鼠标指针名称cursorArrow，OffsetY 设为50（因为之前它与LayoutRoot有-50的偏差）：

运行程序便可看到新的鼠标指针效果，源代码下载：