处理点击事件

请选择平台： Android iOS JavaScript

让数据地图项响应 click 事件，并将其用于 根据用户互动更改地图项的外观。

编写点击事件处理脚本

当地图项图层上发生点击事件时，Maps SDK for Android 会将 FeatureClickEvent 对象传递给事件处理脚本。

使用 FeatureClickEvent.getFeatures() 方法获取特征列表 所受点击次数的影响

处理地图项图层事件

请按照以下步骤处理数据集图层上的事件。在本课中， 例如，您要对表示 所选地图项。

注意 ：在此示例中，数据集的 globalid 属性包含一个唯一的 每个多边形的标识符。然后，您可以检查多边形的 globalid 以便仅将蓝色样式应用于该多边形。

致电后 FeatureLayer.setFeatureStyle(), 样式工厂函数用于设置 数据集。要在事件处理脚本中更新数据集的样式，您必须 调用 FeatureLayer.setFeatureStyle() 以在所有数据集上设置更新后的样式 功能。

1. 按照 开始 以创建新的地图 ID 和地图样式。请务必启用数据集 地图项图层。

2. 确保您的类实现了 FeatureLayer.OnFeatureClickListener。

3. 通过调用 FeatureLayer.addOnFeatureClickListener()。

   Kotlin

   private var datasetLayer: FeatureLayer? = null
   // The globalid of the clicked dataset feature.
   var lastGlobalId: String? = null
   
   override fun onMapReady(googleMap: GoogleMap) {
     // Get the DATASET feature layer.
     datasetLayer = googleMap.getFeatureLayer(FeatureLayerOptions.Builder()
       .featureType(FeatureType.DATASET)
       // Specify the dataset ID.
       .datasetId(YOUR_DATASET_ID)
       .build())
   
     // Register the click event handler for the Datasets layer.
     datasetLayer?.addOnFeatureClickListener(this)
   
     // Apply default style to all features on load to enable clicking.
     styleDatasetsLayer()
   }
   
   // Define the click event handler to set lastGlobalId to globalid of selected feature.
   override fun onFeatureClick(event: FeatureClickEvent) {
     // Get the dataset feature affected by the click.
     val clickFeatures: MutableList<Feature> = event.features
     lastGlobalId = null
     if (clickFeatures.get(0) is DatasetFeature) {
         lastGlobalId = ((clickFeatures.get(0) as DatasetFeature).getDatasetAttributes().get("globalid"))
         // Remember to reset the Style Factory.
         styleDatasetsLayer()
     }
   }
   

   Java

   private FeatureLayer datasetLayer;
   // The globalid of the clicked dataset feature.
   String lastgobalid = null;
   
   @Override
   public void onMapReady(GoogleMap map) {
   
     // Get the DATASET feature layer.
     datasetLayer = map.getFeatureLayer(new FeatureLayerOptions.Builder()
       .featureType(FeatureType.DATASET)
       // Specify the dataset ID.
       .datasetId(YOUR_DATASET_ID)
       .build());
   
     // Register the click event handler for the Datasets layer.
     datasetLayer.addOnFeatureClickListener(this);
   
     // Apply default style to all features on load to enable clicking.
     styleDatasetsLayer();
   }
   
   @Override
   // Define the click event handler.
   public void onFeatureClick(FeatureClickEvent event) {
     // Get the dataset feature affected by the click.
     List<Feature> clickFeatures = event.getFeatures();
     lastgobalid = null;
     if (clickFeatures.get(0) instanceof DatasetFeature) {
         lastgobalid = ((DatasetFeature) clickFeatures.get(0)).getDatasetAttributes().get("globalid");
         // Remember to reset the Style Factory.
         styleDatasetsLayer();
     }
   }
   

4. 对选定地图项应用蓝色填充颜色，将绿色填充所有其他地图项 功能。只有可见地图项可供点击。

   Kotlin

   // Set fill and border for all features.
   private fun styleDatasetsLayer() {
       // Create the style factory function.
       val styleFactory = FeatureLayer.StyleFactory { feature: Feature ->
   
       // Check if the feature is an instance of DatasetFeature.
       if (feature is DatasetFeature) {
         val globalIDs: MutableMap<String, String> = feature.getDatasetAttributes()
         // Determine globalid attribute.
         val globalID = globalIDs!!["globalid"]
         // Set default colors to to green.
         var fillColor = 0x800000ff
         var strokeColor = 0xff0000ff
         if (globalID == lastGlobalId) {
           // Color selected area blue.
           fillColor = 0x8000ff00
           strokeColor = 0xff00ff00
         }
         return@StyleFactory FeatureStyle.Builder()
             .fillColor(fillColor)
             .strokeColor(strokeColor)
             .build()
       }
       return@StyleFactory null
     }
   
     // Apply the style factory function to the dataset feature layer.
     datasetLayer?.setFeatureStyle(styleFactory)
   }
   

   Java

   // Set default green fill and border for all features.
   private void styleDatasetsLayer() {
     // Create the style factory function.
     FeatureLayer.StyleFactory styleFactory = (Feature feature) -> {
   
     // Check if the feature is an instance of DatasetFeature.
     if (feature instanceof DatasetFeature) {
   
       // Check if "globalid" attribute of feature is the "globalid" of clicked feature.
       Map<String, String> globalIDs = ((DatasetFeature) feature).getDatasetAttributes();
       String globalID = globalIDs.get("globalid");
       // Set default colors to green.
       int fillColor = 0x4000ff00;
       int strokeColor = 0xff00ff00;
       if (Objects.equals(globalID, lastgobalid)) {
         // Color selected area blue.
         fillColor = 0x400000ff;
         strokeColor = 0xff0000ff;
       }
       return new FeatureStyle.Builder()
         .fillColor(fillColor)
         .strokeColor(strokeColor)
         .strokeWidth(2)
         .build();
       }
       return null;
     };
   
     // Apply the style factory function to the feature layer.
     datasetLayer.setFeatureStyle(styleFactory);
   }