wpf-118765-controls-and-libraries-map-control-examples-gis-data-searching-how-to-implement-a-custom-search-provider.md
This example demonstrates how to create a custom search provider.
To do this, design a class that inherits the InformationDataProviderBase class and implement the CreateData method in it. Then, design a class that inherits the IInformationData interface and override its IInformationData.OnDataResponse event. Implement the Search method to provide custom search logic.
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:CustomSearchProvider"
xmlns:dxm="http://schemas.devexpress.com/winfx/2008/xaml/map"
x:Class="CustomSearchProvider.MainWindow"
mc:Ignorable="d"
Title="MainWindow" Height="503" Width="521">
<Grid>
<dxm:MapControl x:Name="mapControl">
<dxm:ImageLayer>
<dxm:OpenStreetMapDataProvider/>
</dxm:ImageLayer>
<dxm:InformationLayer x:Name="infoLayer"/>
</dxm:MapControl>
</Grid>
</Window>
using DevExpress.Xpf.Map;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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;
namespace CustomSearchProvider {
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window {
public MainWindow() {
InitializeComponent();
infoLayer.DataProvider = new SearchProvider();
}
}
public class SearchProvider : InformationDataProviderBase, ISearchPanelRequestSender {
protected new SearchData Data { get { return (SearchData)base.Data; } }
public IEnumerable<LocationInformation> Addresses { get { return Data.Addresses; } }
public override bool IsBusy {
get { return false; }
}
protected override IInformationData CreateData() {
return new SearchData();
}
public void SearchByString(string keyword) {
Data.Search(keyword);
}
public override void Cancel() {
throw new NotImplementedException();
}
protected override MapDependencyObject CreateObject() {
return new SearchProvider();
}
}
public class SearchData : IInformationData {
readonly List<LocationInformation> addresses = new List<LocationInformation>();
public IEnumerable<LocationInformation> Addresses { get { return addresses; } }
public event EventHandler<RequestCompletedEventArgs> OnDataResponse;
RequestCompletedEventArgs CreateEventArgs() {
MapItem[] items = new MapItem[addresses.Count];
for (int i = 0; i < items.Length; i++)
items[i] = new MapPushpin() { Location = addresses[i].Location, Information = addresses[i].Address.FormattedAddress, Text = (i + 1).ToString() };
return new RequestCompletedEventArgs(items, null, false, null);
}
protected void RaiseChanged() {
if (OnDataResponse != null)
OnDataResponse(this, CreateEventArgs());
}
public void Search(string keyword) {
Random rnd = new Random(DateTime.Now.Millisecond);
addresses.Clear();
int length = keyword.Length;
for (int i = 0; i < length; i++) {
LocationInformation info = new LocationInformation();
string address = keyword + " " + i.ToString();
info.Address = new Address(address);
info.Location = new GeoPoint(rnd.Next(180) - 90, rnd.Next(360) - 180);
info.DisplayName = address;
addresses.Add(info);
}
RaiseChanged();
}
}
public class Address : AddressBase {
public Address(string address) {
this.FormattedAddress = address;
}
protected override MapDependencyObject CreateObject() {
return new Address(this.FormattedAddress);
}
}
}
Imports System
Imports System.Collections.Generic
Imports System.Configuration
Imports System.Data
Imports System.Linq
Imports System.Threading.Tasks
Imports System.Windows
Namespace CustomSearchProvider
''' <summary>
''' Interaction logic for App.xaml
''' </summary>
Partial Public Class App
Inherits Application
End Class
End Namespace
<Application x:Class="CustomSearchProvider.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:CustomSearchProvider"
StartupUri="MainWindow.xaml">
<Application.Resources>
</Application.Resources>
</Application>
Imports DevExpress.Xpf.Map
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Text
Imports System.Threading.Tasks
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Navigation
Imports System.Windows.Shapes
Namespace CustomSearchProvider
''' <summary>
''' Interaction logic for MainWindow.xaml
''' </summary>
Partial Public Class MainWindow
Inherits Window
Public Sub New()
InitializeComponent()
infoLayer.DataProvider = New SearchProvider()
End Sub
End Class
Public Class SearchProvider
Inherits InformationDataProviderBase
Implements ISearchPanelRequestSender
Protected Shadows ReadOnly Property Data() As SearchData
Get
Return CType(MyBase.Data, SearchData)
End Get
End Property
Public ReadOnly Property Addresses() As IEnumerable(Of LocationInformation) Implements ISearchPanelRequestSender.Addresses
Get
Return Data.Addresses
End Get
End Property
Public Overrides ReadOnly Property IsBusy() As Boolean
Get
Return False
End Get
End Property
Protected Overrides Function CreateData() As IInformationData
Return New SearchData()
End Function
Public Sub SearchByString(ByVal keyword As String) Implements ISearchPanelRequestSender.SearchByString
Data.Search(keyword)
End Sub
Public Overrides Sub Cancel()
Throw New NotImplementedException()
End Sub
Protected Overrides Function CreateObject() As MapDependencyObject
Return New SearchProvider()
End Function
End Class
Public Class SearchData
Implements IInformationData
Private ReadOnly addresses_Renamed As New List(Of LocationInformation)()
Public ReadOnly Property Addresses() As IEnumerable(Of LocationInformation)
Get
Return addresses_Renamed
End Get
End Property
Public Event OnDataResponse As EventHandler(Of RequestCompletedEventArgs) Implements IInformationData.OnDataResponse
Private Function CreateEventArgs() As RequestCompletedEventArgs
Dim items(addresses_Renamed.Count - 1) As MapItem
For i As Integer = 0 To items.Length - 1
items(i) = New MapPushpin() With { _
.Location = addresses_Renamed(i).Location, _
.Information = addresses_Renamed(i).Address.FormattedAddress, _
.Text = (i + 1).ToString() _
}
Next i
Return New RequestCompletedEventArgs(items, Nothing, False, Nothing)
End Function
Protected Sub RaiseChanged()
RaiseEvent OnDataResponse(Me, CreateEventArgs())
End Sub
Public Sub Search(ByVal keyword As String)
Dim rnd As New Random(Date.Now.Millisecond)
addresses_Renamed.Clear()
Dim length As Integer = keyword.Length
For i As Integer = 0 To length - 1
Dim info As New LocationInformation()
Dim address As New String(keyword & " " & i.ToString())
info.Address = New Address(address)
info.Location = New GeoPoint(rnd.Next(180) - 90, rnd.Next(360) - 180)
info.DisplayName = address
addresses_Renamed.Add(info)
Next i
RaiseChanged()
End Sub
End Class
Public Class Address
Inherits AddressBase
Public Sub New(ByVal address As String)
Me.FormattedAddress = address
End Sub
Protected Overrides Function CreateObject() As MapDependencyObject
Return New Address(Me.FormattedAddress)
End Function
End Class
End Namespace