【发布时间】：2013-06-28 18:59:49
【问题描述】：
我在此处找到的 bing 地图示例多边形搜索有点问题：
Polygon search is about halfway down this link.
public bool polygonSearch(LocationCollection points, double lat, double lon)
{
MapPolygon poly = new MapPolygon();
int i = 0;
int j = points.Count - 1;
bool inPoly = false;
for (i = 0; i < points.Count; i++)
{
if (points[i].Longitude < lon && points[j].Longitude >= lon || points[j].Longitude < lon && points[i].Longitude >= lon)
{
if (points[i].Latitude + (lon - points[i].Longitude) / (points[j].Longitude - points[i].Longitude) * (points[j].Latitude - points[i].Latitude) < lat)
{
inPoly = !inPoly;
}
}
j = i;
}
return inPoly;
}
我使用ViewportPointToLocation 来获取鼠标坐标并在我的鼠标点击时添加一个图钉。
Point mousePosition = e.GetPosition(myMap);
Microsoft.Maps.MapControl.WPF.Location pinLocation = myMap.ViewportPointToLocation(mousePosition);
// Convert the mouse coordinates to a location on the map
// The pushpin to add to the map.
Pushpin pin = new Pushpin();
pin.Location = pinLocation;
pin.Content = "Cust";
pin.Heading = 0;
// Adds the pushpin to the map
myMap.Children.Add(pin);
这是我使用多边形搜索来查看我是否在多边形内单击的地方。
polygonSearch(polygon.Locations, pin.Location.Latitude, pin.Location.Longitude))
如下图所示，我将标签设置为“在送货区域内”或“客户在区域外”，具体取决于天气多边形搜索返回真或假。
在处理多边形边缘时似乎不起作用。有更多经验的人可以告诉我我哪里错了吗？
下面的完整代码示例：
您需要引用 Microsoft.Maps.MapControl.WPF.dll 才能使其正常工作。
我只做了一个演示，其中包含 bing 地图控制地图、一个告诉我们多边形搜索输出的标签，以及一个允许您在多边形内搜索的复选框。
要制作多边形，只需右键单击要绘制的地图，然后按“退出”即可结束多边形的绘制。然后您可以单击“左键搜索地址”复选框并在多边形内搜索。
正如您将看到的，当我们看到我们在刚刚绘制的多边形内单击时，来自 MSDN 的多边形搜索返回区域外！
MainWindow.xaml
<Window x:Class="PolygonSearch.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:m="clr-namespace:Microsoft.Maps.MapControl.WPF;assembly=Microsoft.Maps.MapControl.WPF"
Title="MainWindow" Height="350" Width="525" KeyDown="Window_KeyDown">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="100*"/>
</Grid.RowDefinitions>
<StackPanel>
<Label Content="Label" Height="28" HorizontalAlignment="Left" Margin="10,10,0,0" Name="lbl_arearsult" Grid.Row="0" VerticalAlignment="Top" />
<CheckBox Content="Search Address by left click" Height="16" HorizontalAlignment="Left" Margin="10,10,0,0" Name="chk_search" VerticalAlignment="Top" />
</StackPanel>
<m:Map x:Name="myMap" Grid.Row="1" CredentialsProvider="your_bing_map_key" Mode="AerialWithLabels" MouseLeftButtonDown="myMap_MouseDown" MouseRightButtonDown="myMap_MouseRightButtonDown" KeyDown="myMap_KeyDown" />
</Grid>
</Window>
MainWindow.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Microsoft.Maps.MapControl.WPF;
namespace PolygonSearch
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
LocationCollection drawPolyPoints = new LocationCollection();
public MainWindow()
{
InitializeComponent();
}
public bool polygonSearch(LocationCollection points, double lat, double lon)
{
MapPolygon poly = new MapPolygon();
int i = 0;
int j = points.Count - 1;
bool inPoly = false;
for (i = 0; i < points.Count; i++)
{
if (points[i].Longitude < lon && points[j].Longitude >= lon || points[j].Longitude < lon && points[i].Longitude >= lon)
{
if (points[i].Latitude + (lon - points[i].Longitude) / (points[j].Longitude - points[i].Longitude) * (points[j].Latitude - points[i].Latitude) < lat)
{
inPoly = !inPoly;
}
}
j = i;
}
return inPoly;
}
private void myMap_KeyDown(object sender, KeyEventArgs e)
{
if (e.Key == System.Windows.Input.Key.Escape)
{
MapPolygon polygon = new MapPolygon();
polygon.Fill = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Colors.Blue);
polygon.Stroke = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Colors.Green);
polygon.StrokeThickness = 5;
polygon.Opacity = 0.7;
polygon.Locations = drawPolyPoints;
polygon.Tag = "1388_q3_polygon_5";
myMap.Children.Add(polygon);
//drawPolyPoints.Clear();
for (int p = 0; p < myMap.Children.Count; p++)
{
object entity = myMap.Children[p];
if (entity is Microsoft.Maps.MapControl.WPF.Pushpin)
{
if (((Microsoft.Maps.MapControl.WPF.Pushpin)entity).Content.ToString() == "Vertice")
myMap.Children.Remove(((Microsoft.Maps.MapControl.WPF.Pushpin)entity));
}
}
}
}
private void myMap_MouseDown(object sender, MouseButtonEventArgs e)
{
if (chk_search.IsChecked == true)
{
Point mousePosition = e.GetPosition(myMap);
Microsoft.Maps.MapControl.WPF.Location pinLocation = myMap.ViewportPointToLocation(mousePosition);
// Convert the mouse coordinates to a location on the map
// The pushpin to add to the map.
Pushpin pin = new Pushpin();
pin.Location = pinLocation;
pin.Content = "Cust";
pin.Heading = 0;
// Adds the pushpin to the map
myMap.Children.Add(pin);
bool inArea = false;
for (int p = 0; p < myMap.Children.Count; p++)
{
object entity = myMap.Children[p];
if (entity is Microsoft.Maps.MapControl.WPF.MapPolygon)
{
if (polygonSearch(((Microsoft.Maps.MapControl.WPF.MapPolygon)entity).Locations, pin.Location.Latitude, pin.Location.Longitude))
{
string[] quadAttributes = ((Microsoft.Maps.MapControl.WPF.MapPolygon)entity).Tag.ToString().Split('_');
lbl_arearsult.Content = "Within delivery area ";
inArea = true;
break;
}
else
{
inArea = false;
}
}
}
if (inArea != true)
lbl_arearsult.Content = "Customer out of area. ";
}
}
private void myMap_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
Point mousePosition = e.GetPosition(myMap);
Microsoft.Maps.MapControl.WPF.Location pinLocation = myMap.ViewportPointToLocation(mousePosition);
// Convert the mouse coordinates to a location on the map
// The pushpin to add to the map.
Pushpin pin = new Pushpin();
pin.Location = pinLocation;
pin.Content = "Vertice";
// Adds the pushpin to the map
myMap.Children.Add(pin);
drawPolyPoints.Add(pin.Location);
}
private void Window_KeyDown(object sender, KeyEventArgs e)
{
myMap_KeyDown(sender, e);
}
}
}
注意：此设计仅适用于创建 1 个要搜索的多边形，但您仍然可以直观地看到我的多边形搜索失败的地方。
编辑：
非常感谢 KeyboardP，我们发现如果您完全放大，然后绘制多边形，然后搜索，则不存在该问题。但是如果我们绘制它，然后缩放，我们会看到同样的问题。
我还调试并确认 LocationCollection 多边形在不同缩放级别上是相同的
列表项
【问题讨论】：
-
没人注意到这个问题吗？
-
能否向我们提供您的 polygonSearch 方法的内容（如果您担心隐私，可以省略实际的纬度）？我们无法对看不到的一段代码进行故障排除。
-
现在要在此处添加完整的代码示例，感谢您抽出宝贵时间。
-
@mech 我添加了一个演示
-
@ChrisBuckler 它是完全起作用还是仅在它不靠近边缘时起作用？