界面控件DevExpress WinForms - 如何实现地图搜索功能？-控件新闻-慧都网

界面控件DevExpress WinForms - 如何实现地图搜索功能？

翻译|使用教程|编辑：龚雪|2022-09-20 09:59:43.987|阅读 144 次

概述：本文将为大家介绍使用DevExpress WinForms控件开发地图应用时如何实现搜索功能，欢迎下载相关产品体验！

启用搜索

执行以下操作以在Map控件中启用搜索：

创建一个信息层并将其添加到地图中，信息层提供了表示从地图控件中的搜索服务获得的 GIS 数据的矢量元素。
创建BingSearchDataProvider 或OsmSearchDataProvider实例并将其分配给InformationLayer.DataProvider属性。
使用BingMapDataProviderBase.BingKey 属性为Bing Data Provider指定Bing Maps key。

下面的代码片段显示了如何执行此操作。

private void Form1_Load(object sender, System.EventArgs e) {
// ...

InformationLayer infoLayer = new InformationLayer();
map.Layers.Add(infoLayer);
BingSearchDataProvider searchProvider = new BingSearchDataProvider();
infoLayer.DataProvider = searchProvider;
searchProvider.BingKey = yourBingKey;
}

VB.NET

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
' ....

Dim infoLayer As New InformationLayer()
map.Layers.Add(infoLayer)
Dim searchProvider As New BingSearchDataProvider()
infoLayer.DataProvider = searchProvider
searchProvider.BingKey = yourBingKey
End Sub

您还可以自定义搜索结果计数：

private void Form1_Load(object sender, System.EventArgs e) {
// ...
searchProvider.SearchOptions.ResultsCount = 5;
}

VB.NET

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
' ....
searchProvider.SearchOptions.ResultsCount = 5
End Sub

当Map控件包含提供搜索数据的信息层时，Map控件会自动调用其内置的搜索面板（MapControl.ShowSearchPanel默认设置为 true）。

使用自定义 UI

Map控件提供带有附加参数的搜索功能，例如国家地区或邮政编码。使用这种方法，您可以构建自定义搜索面板以从搜索服务中获取额外的搜索结果。

注意：将MapControl.ShowSearchPanel属性设置为 false 以在使用此方法时禁用默认搜索面板。

要开始搜索位置，请调用BingSearchDataProvider.Search或 OsmSearchDataProvider.Search方法。

例如，应用程序的 UI 包含一个名为“tbKeywords”的文本框和一个名为“btnSearch”的按钮。要开始搜索，请单击调用以下 Search 方法重载的 Search 按钮：

private void OnClick(object sender, EventArgs e) {
searchProvider.Search(tbKeywords.Text);
}

VB.NET

Private Sub OnClick(ByVal sender As Object, ByVal e As EventArgs) Handles btnSearch.Click
searchProvider.Search(tbKeywords.Text)
End Sub

搜索结果

要获取搜索结果，请处理BingSearchDataProvider.SearchCompleted或OsmSearchDataProvider.SearchCompleted事件。

SearchCompleted 事件处理程序参数的SearchCompletedEventArgs.RequestResult提供SearchRequestResult后代类实例来存储搜索结果。

结果包含与搜索位置关联的显示名称、地址和地理坐标（纬度和经度）。

Form1.cs

void OnSearchCompleted(object sender, BingSearchCompletedEventArgs e) {
if(e.Cancelled) return;
if(e.RequestResult.ResultCode != RequestResultCode.Success) {
meResult.Text = "The Bing Search service does not work for this location.";
return;
}

StringBuilder resultList = new StringBuilder("");
int resCounter = 1;
foreach(BingLocationInformation resultInfo in e.RequestResult.SearchResults) {
resultList.Append(String.Format("Result {0}: \r\n", resCounter));
resultList.Append(String.Format("Name: {0}\r\n", resultInfo.DisplayName));
resultList.Append(String.Format("Address: {0}\r\n", resultInfo.Address.FormattedAddress));
resultList.Append(String.Format("Confidence level: {0}\r\n", resultInfo.Confidence));
resultList.Append(String.Format("Geographic coordinates: {0}\r\n", resultInfo.Location));
resultList.Append(String.Format("Match code: {0}\r\n", resultInfo.MatchCode));
resultList.Append(String.Format("______________________________\r\n"));
resCounter++;
}
meResult.Text = resultList.ToString();
}

Form1.vb

Private Sub OnSearchCompleted(ByVal sender As Object, ByVal e As BingSearchCompletedEventArgs)
If e.Cancelled Then
Return
End If
If e.RequestResult.ResultCode <> RequestResultCode.Success Then
meResult.Text = "The Bing Search service does not work for this location."
Return
End If

Dim resultList As New StringBuilder("")
Dim resCounter As Integer = 1
For Each resultInfo As BingLocationInformation In e.RequestResult.SearchResults
resultList.Append(String.Format("Result {0}: " & ControlChars.CrLf, resCounter))
resultList.Append(String.Format("Name: {0}" & ControlChars.CrLf, resultInfo.DisplayName))
resultList.Append(String.Format("Address: {0}" & ControlChars.CrLf, resultInfo.Address.FormattedAddress))
resultList.Append(String.Format("Confidence level: {0}" & ControlChars.CrLf, resultInfo.Confidence))
resultList.Append(String.Format("Geographic coordinates: {0}" & ControlChars.CrLf, resultInfo.Location))
resultList.Append(String.Format("Match code: {0}" & ControlChars.CrLf, resultInfo.MatchCode))
resultList.Append(String.Format("______________________________" & ControlChars.CrLf))
resCounter += 1
Next resultInfo
meResult.Text = resultList.ToString()
End Sub

“New York”关键字的搜索结果如下图所示。