【Silverlight】Bing Maps开发应用与技巧二：自定义图钉标注控件和动态ToolPanel-阿里云开发者社区

　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 51.7942001036199,-228.166407297221 56.0964631917223,
                          -224.103097789728 68.1963801884179,-208.309435634954 69.289336364603,
                          -191.492424677005 70.6231971699074,-170.968460931381 68.290878635012,
                          -158.519576085084 59.6252929380878,-143.46295614065 52.4136905999628,
                          -130.932641056522 38.9633656169578,-121.172558189545 25.9663459471247,
                          -99.9756667119496 22.717070324265,-94.6763733347819 19.5096780307535,
                          -85.8535122559554 16.5262691191198,-75.6002242070549 15.0345529933047,
                          -70.4735161130636 13.5988258504601,-64.9891717094285 12.2418500593682,
                          -59.4087874394669 8.8494006958964,-45.4578438671403 0.658368923825747,
                          -0.264830522697093 0.658368923825747,-0.264830522697093L0.658368923825747,
                          -0.264830522697093C0.658368923825747,-0.264830522697093 -6.20713033738298,
                          -39.8775058725022 -10.9565428086754,-59.4087721806768 -13.6705143479304,
                          -70.5696227914182 -16.6994467050881,-81.3462113972954 -19.8613212892067,
                          -89.645756433626 -21.4422436994774,-93.7955199281247 -23.0564059677924,
                          -97.3260283129902 -24.6810425111283,-99.9756667119496 -37.6780541099905,
                          -121.172569912188 -51.1284623692131,-130.932797619228 -58.3399704286158,
                          -143.462940881861 -67.0055167526496,-158.519492415143 -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" Margin ="-28.398,-30.999,0,0" Width ="35" Height ="30.754" VerticalAlignment ="Top"
                          Fill ="#59000000" HorizontalAlignment ="Left" d:LayoutOverrides ="Width, Height" IsHitTestVisible ="False" >
                         < Path.RenderTransform >
                             < TransformGroup >
                                 < ScaleTransform ScaleX ="1" ScaleY ="1" />
                                 < SkewTransform AngleX ="-57.547" AngleY ="0" />
                                 < RotateTransform Angle ="0" />
                                 < TranslateTransform X ="45.252" Y ="0" />
                             </ TransformGroup >
                         </ Path.RenderTransform >
                     </ Path >
                     < Path Stretch ="Fill" Stroke ="#FF000000" 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 51.7942001036199,
                          -228.166407297221 56.0964631917223,-224.103097789728 68.1963801884179,
                          -208.309435634954 69.289336364603,-191.492424677005 70.6231971699074,
                          -170.968460931381 68.290878635012,-158.519576085084 59.6252929380878,
                          -143.46295614065 52.4136905999628,-130.932641056522 38.9633656169578,
                          -121.172558189545 25.9663459471247,-99.9756667119496 22.717070324265,
                          -94.6763733347819 19.5096780307535,-85.8535122559554 16.5262691191198,
                          -75.6002242070549 15.0345529933047,-70.4735161130636 13.5988258504601,
                          -64.9891717094285 12.2418500593682,-59.4087874394669 8.8494006958964,
                          -45.4578438671403 0.658368923825747,-0.264830522697093 0.658368923825747,
                          -0.264830522697093L0.658368923825747,-0.264830522697093C0.658368923825747,
                          -0.264830522697093 -6.20713033738298,-39.8775058725022 -10.9565428086754,
                          -59.4087721806768 -13.6705143479304,-70.5696227914182 -16.6994467050881,
                          -81.3462113972954 -19.8613212892067,-89.645756433626 -21.4422436994774,
                          -93.7955199281247 -23.0564059677924,-97.3260283129902 -24.6810425111283,
                          -99.9756667119496 -37.6780541099905,-121.172569912188 -51.1284623692131,
                          -130.932797619228 -58.3399704286158,-143.462940881861 -67.0055167526496,
                          -158.519492415143 -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。

本文转自 beniao 51CTO博客，原文链接：http://blog.51cto.com/beniao/300734，如需转载请自行联系原作者

【Silverlight】Bing Maps开发应用与技巧二：自定义图钉标注控件和动态ToolPanel

热门文章

最新文章

相关电子书