在Bing Maps Silverlight Control中以及为我们提供了地图图钉控件Pushpin，我曾经在《使用图钉层（Pushpin layer）及地图图层（MapLayer）》一文中介绍过他的使用方法，本篇主要介绍如何自定义图钉标注控件以及对他的一些扩展，比如实现图钉的动态ToolPanel。
关于图钉的UI外观的设计这里就不详细介绍了，通过Blend可以快速的构建UI界面。首先介绍下我的实现思想，通过Path构建图钉标注控件的UI外观，控件整体布局使用Grid布局，分别在Grid容器里设计好图钉UI外观效果和需要动态提示的ToolPanel(使用Border布局设计)，默认将ToolPanel隐藏，在后台代码中通过鼠标事件进行控制其是否出现；另外还布局了一个TextBlock控件，用于出现图钉标注上的内容。下面是定义好的图钉风格的样式：
自定义图钉样式 <Style x:Name="PushpinStyle" TargetType="Controls:PushPinControl"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="Controls:PushPinControl"> <Grid x:Name="grdRoot" Height="Auto" Width="Auto" HorizontalAlignment="Stretch" RenderTransformOrigin="0,0"> <Grid.RenderTransform> <TransformGroup> <ScaleTransform x:Name="_ScaleTransform" ScaleX="1" ScaleY="1"/> <SkewTransform/> <RotateTransform/> <TranslateTransform/> </TransformGroup> </Grid.RenderTransform> <Path Stretch="Fill" Opacity="1" RenderTransformOrigin="0.501,0.281" Data="M0,-250L6.09909264359567, -250C7.86508433137037,-249.883679757668 9.5771753004554,-249.696968148304 11.2361413649071, -249.457603405072 24.5078612249376,-247.542676877067 34.3794798686271, -242.257907887612 41.2465583494687,-237.283319185337 44.6800986937064, -234.796020219885 47.3625022581612,-232.386267374123 49.3432151487858, -230.514059732522 50.3335754087938,-229.577954004373 51.1485091856508, -228.776236246195 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-69.3378901087436,-170.968446571251 -68.0040291139176, -191.492413232913 -66.9110789415046,-208.309331812531 -54.8111481537909, -224.103105568266 -50.508885223533,-228.166399667826 -47.9261288596012, -230.605716191039 -42.6354741589363,-236.115224319832 -34.2414024659624, -241.014917085726 -30.0443655550756,-243.464752007233 -25.0714708225116, -245.762135285075 -19.2732761689687,-247.447058389738 -16.3741806336881, -248.289518545224 -13.2687567063844,-248.978864381863 -9.95082648482475, -249.457595894886 -8.29186423506778,-249.6969603997 -6.57977326598088, -249.883671889854 -4.81378157820587,-250z" StrokeThickness="2.5" HorizontalAlignment="Left" Margin="-18,-63.25,0,0" x:Name="shpPushpin" Width="35" d:LayoutOverrides="Width" Height="63" VerticalAlignment="Top" Cursor="Hand"> <Path.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1"/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </Path.RenderTransform> <Path.Fill> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FFFFF77F" Offset="0"/> <GradientStop Color="#FFFCF14E" Offset="1"/> </LinearGradientBrush> </Path.Fill> </Path> <TextBlock TextWrapping="Wrap" d:LayoutOverrides="Height, GridBox" RenderTransformOrigin="0.51,0.491" VerticalAlignment="Top" TextAlignment="Center" Margin="-15.55,-60,0,0" x:Name="txtTitle" Width="30" FontSize="24" Visibility="Visible" FontFamily="Verdana" HorizontalAlignment="Left" IsHitTestVisible="False" > <TextBlock.RenderTransform> <TransformGroup> <ScaleTransform/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </TextBlock.RenderTransform> </TextBlock> <Border x:Name="ToolPanel" VerticalAlignment="Stretch" Background="#A82D2D2D" CornerRadius="8,8,8,8" Visibility="Collapsed" BorderBrush="#FF626262" BorderThickness="2,2,2,2" ScrollViewer.HorizontalScrollBarVisibility="Visible" RenderTransformOrigin="0.5,0.5" Grid.Row="0" Width="300" Height="200"> <Border.RenderTransform> <TransformGroup> <ScaleTransform/> <SkewTransform/> <RotateTransform/> <TranslateTransform X="20" Y="-75"/> </TransformGroup> </Border.RenderTransform> <StackPanel VerticalAlignment="Top" Margin="5,10, 5, 10"> <Grid Height="29" VerticalAlignment="Top"> <TextBlock Height="25" Width="346" Text="标题内容" TextWrapping="Wrap" Foreground="#FFF0E7E7" FontSize="16" HorizontalAlignment="Left" Margin="12,3,0,1"/> </Grid> <StackPanel VerticalAlignment="Top"> <Border x:Name="ContentBorder" Background="#FF000000" CornerRadius="8,8,8,8" VerticalAlignment="Top" Margin="0,3,0,3" Padding="0,8,0,8" Opacity="0.68" MinHeight="200"> <TextBlock Text="显示内容" Foreground="White" Margin="3" ></TextBlock> </Border> </StackPanel> </StackPanel> </Border> </Grid> </ControlTemplate> </Setter.Value> </Setter></Style>
接下来要做的就是实现图标注控件的定义以及动态控制ToolPanel控件的显示与否了，主要思路就是通过引用上面定义的样式，以模板的方式从样式里获取到相应的控件元素进行动态控制，详细见如下代码：
/// <summary>/// 自定义图钉控件/// </summary>public class PushPinControl : ContentControl{ private string Text; public PushPinControl(String text) { //设置图钉标注控件的标注内容 this.Text = text == "" ? "M" : text; DefaultStyleKey = typeof(PushPinControl); //为当前对象引用样式，从全局资源里读取 this.Style = Application.Current.Resources["PushpinStyle"] as Style; } public override void OnApplyTemplate() { base.OnApplyTemplate(); //从样式模板中获取TextBlock控件 var textBlock = GetTemplateChild("txtTitle") as TextBlock; textBlock.Text = this.Text; //从样式模板中获取ToolPanel(既Border布局实现的，详细见样式的定义)控件 var ToolPanelBorder = GetTemplateChild("ToolPanel") as Border; //通过事件动态控制ToolPanel的显示和隐藏 this.MouseEnter += (mes, meo) => { ToolPanelBorder.Visibility = Visibility.Visible; }; this.MouseLeave += (mls, mlo) => { ToolPanelBorder.Visibility = Visibility.Collapsed; }; }}
到这里就成功的完成了图钉标注控件的自定义了，接下来看看如何使用这个自定义的图钉标注控件，详见如下代码块：
private void AddPushPin(){ //添加Bing Maps Silverlight Control自带的图钉 //var pushpin = new Pushpin(); //pushpin.Location = new Location(29.5076372217973, 106.489384971208); //添加自定义的图钉 var pushpin = new PushPinControl("D"); MapLayer.AddChild(pushpin, new Location(29.5076372217973, 106.489384971208));}
或许会有人问道，如何动态的实现ToolPanel里显示的内容？要实现这个功能也是非常简单的，首先我们来分析下上面定义的样式里对ToolPanel部分的定义：
<Border x:Name="ToolPanel" VerticalAlignment="Stretch" Background="#A82D2D2D" CornerRadius="8,8,8,8" Visibility="Collapsed" BorderBrush="#FF626262" BorderThickness="2,2,2,2" ScrollViewer.HorizontalScrollBarVisibility="Visible" RenderTransformOrigin="0.5,0.5" Grid.Row="0" Width="300" Height="200"> <Border.RenderTransform> <TransformGroup> <ScaleTransform/> <SkewTransform/> <RotateTransform/> <TranslateTransform X="20" Y="-75"/> </TransformGroup> </Border.RenderTransform> <StackPanel VerticalAlignment="Top" Margin="5,10, 5, 10"> <Grid Height="29" VerticalAlignment="Top"> <TextBlock Height="25" Width="346" Text="标题内容" TextWrapping="Wrap" Foreground="#FFF0E7E7" FontSize="16" HorizontalAlignment="Left" Margin="12,3,0,1"/> </Grid> <StackPanel VerticalAlignment="Top"> <Border x:Name="ContentBorder" Background="#FF000000" CornerRadius="8,8,8,8" VerticalAlignment="Top" Margin="0,3,0,3" Padding="0,8,0,8" Opacity="0.68" MinHeight="200"> <TextBlock Text="显示内容" Foreground="White" Margin="3" ></TextBlock> </Border> </StackPanel> </StackPanel></Border>
使用了Border进行圆角布局，在其内部通过StackPanel垂直布局实现了ToolPanel的的标题和内容两大部分，内容部分并通过Border进行设计，取名为ContentBorder，这是为了实现动态呈现显示内容而设计，整体Border通过TranslateTransform进行一个偏移的处理，也就是让ToolPanel始终显示在图钉标注的右边相应的位置，详细见本文前面提供的截图。
从上面的实现知道ToolPanel是在鼠标的MouseEnter事件执行的时候才会显示的，当鼠标离开就会将其可见性设置为隐藏。了解了这个原理后就可以想到，是否可以从MouseEnter事件中通过某种方法去处理？事件是个非常强大的技术点，这里我们就可以通过事件，将显示内容的Border容器派发处理，通过事件的监听来动态更新其显示内容。首先需要扩展一个事件类：
public delegate void PushpinContentChangedHandler(object sender,PushpinContentChangedEvantAgrs e);public class PushpinContentChangedEvantAgrs : EventArgs{ public Border ContentBorder { get; set; } public PushpinContentChangedEvantAgrs() { } public PushpinContentChangedEvantAgrs(Border ContentBorder) { this.ContentBorder = ContentBorder; }}
接下来为自定义的图钉标注类定义一个事件，事件类型就为上面所定义好的委托类型，传递的事件为PushpinContentChangedEventArgs.
/// <summary>/// 自定义图钉控件/// </summary>public class PushPinControl : ContentControl{ public event PushpinContentChangedHandler ContentChangedEvent;
现在需要做的就是在当前对象的MouseEnter事件中去触发这个事件，将样式里所定义好的用于显示内容的Border对象获取出来，通过事件参数传递派发出去，让事件监听段可以通过该事件获取事件参数进行ToolPanel内容的呈现更新。所有我们需要改写PushPinControl的OnApplyTemplate方法：
public override void OnApplyTemplate(){ base.OnApplyTemplate(); //从样式模板中获取TextBlock控件 var textBlock = GetTemplateChild("txtTitle") as TextBlock; textBlock.Text = this.Text; //从样式模板中获取ToolPanel(既Border布局实现的，详细见样式的定义)控件 var ToolPanelBorder = GetTemplateChild("ToolPanel") as Border; //获取内容Border对象，通过事件将该对象派发出去，在使用段可以通过监听这个事件而获取到内容Border var ContentBorder = GetTemplateChild("ContentBorder") as Border; //通过事件动态控制ToolPanel的显示和隐藏 this.MouseEnter += (mes, meo) => { ToolPanelBorder.Visibility = Visibility.Visible; if (ContentChangedEvent != null) { ContentChangedEvent(this, new PushpinContentChangedEvantAgrs(ContentBorder)); } }; this.MouseLeave += (mls, mlo) => { ToolPanelBorder.Visibility = Visibility.Collapsed; };}
通过ContentChangedEvent事件的监听动态的去改变ToolPanel里的显示内容就可以达到我们的目的了，比如我们动态的将ToolPanel里的显示内容更改为一张图片，上面使用自定义图钉标注的代码将变成下面这样的。
private void AddPushPin(){ //添加Bing Maps Silverlight Control自带的图钉 //var pushpin = new Pushpin(); //pushpin.Location = new Location(29.5076372217973, 106.489384971208); //添加自定义的图钉 var pushpin = new PushPinControl("D"); pushpin.ContentChangedEvent += (sender, o) => { //构造Image对象 用于显示在ToolPanel中 var image = new Image { Width = 100, Height = 100, Margin = new Thickness(8) }; image.Source = new BitmapImage(new Uri("Resources/Smbecker.png", UriKind.RelativeOrAbsolute)); Border border = o.ContentBorder; border.Child = image; }; MapLayer.AddChild(pushpin, new Location(29.5076372217973, 106.489384971208));}
之前有网友问到如何实现可拖拽的图钉标注控件，鉴于篇幅的原因这里就不做介绍，不清楚的朋友可以留言讨论。本篇就介绍到这里，欢迎大家前来交流、讨论、拍砖。
更多学习资料：
MSDN:http://msdn.microsoft.com/en-us/library/ee681890.aspx
官方：http://www.microsoft.com/maps
中国Bing Maps:http://cn.bing.com/ditu/
官方SDK：http://www.microsoft.com/maps/isdk/silverlight/
版权说明
本文属原创文章，欢迎转载且注明文章出处，其版权归作者和博客园共有。
作 者：Beniao 微软Bing Maps开发QQ群：75662563
文章出处：http://beniao.cnblogs.com/ 或 http://www.cnblogs.com/
转载于:https://www.cnblogs.com/beniao/archive/2010/04/19/1712453.html
