处理点击事件

请选择平台： Android iOS JavaScript

您可以让地图项图层响应用户 click 事件，以获取所点击边界的地点 ID 和地图项类型。下面这个示例地图展示了“国家/地区”图层的边界，该地图使用了事件处理脚本，用于为所点击的与所选国家/地区相关联的多边形应用样式。

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 获取点击的纬度和经度坐标，以及受点击影响的地图项列表。

处理地图项图层事件

如需处理地图项图层上的事件，请按以下步骤操作。在此示例中，您将为“Country”地图项图层定义点击事件处理脚本，以便对表示所选国家/地区的多边形应用红色填充。

当您调用 FeatureLayer.setFeatureStyle() 时，样式工厂函数会为地图项图层中的所有地图项设置样式。如需在事件处理脚本中更新地图项的样式，您必须调用 FeatureLayer.setFeatureStyle() 以便为所有地图项设置更新后的样式。

  1. 按照开始使用中的步骤创建新的地图 ID 和地图样式（如果您尚未执行此操作）。请务必启用国家/地区地图项图层。

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

  3. 通过调用 FeatureLayer.addOnFeatureClickListener() 为特征点击事件注册事件处理脚本。

    Java

    private FeatureLayer countryLayer;
    
@Override
public void onMapReady(GoogleMap map) {
    
  // Get the COUNTRY feature layer.
  countryLayer = map.getFeatureLayer(new FeatureLayerOptions.Builder()
    .featureType(FeatureType.COUNTRY)
    .build());
    
  // Register the click event handler for the Country layer.
  countryLayer.addOnFeatureClickListener(this);
    
  // Apply default style to all countries on load to enable clicking.
  styleCountryLayer();
}
    
// Set default fill and border for all countries to ensure that they respond
// to click events.
private void styleCountryLayer() {
  FeatureLayer.StyleFactory styleFactory = (Feature feature) -> {
    return new FeatureStyle.Builder()
      // Set the fill color for the country as white with a 10% opacity.
      .fillColor(Color.argb(0.1, 0, 0, 0))
      // Set border color to solid black.
      .strokeColor(Color.BLACK)
      .build();
  };
    
  // Apply the style factory function to the country feature layer.
  countryLayer.setFeatureStyle(styleFactory);
}

    Kotlin

    private var countryLayer: FeatureLayer? = null
    
override fun onMapReady(googleMap: GoogleMap) {
  // Get the COUNTRY feature layer.
  countryLayer = googleMap.getFeatureLayer(FeatureLayerOptions.Builder()
    .featureType(FeatureType.COUNTRY)
    .build())
    
  // Register the click event handler for the Country layer.
  countryLayer?.addOnFeatureClickListener(this)
    
  // Apply default style to all countries on load to enable clicking.
  styleCountryLayer()
}
    
// Set default fill and border for all countries to ensure that they respond
// to click events.
private fun styleCountryLayer() {
  val styleFactory = FeatureLayer.StyleFactory { feature: Feature ->
    return@StyleFactory FeatureStyle.Builder()
      // Set the fill color for the country as white with a 10% opacity.
      .fillColor(Color.argb(0.1f, 0f, 0f, 0f))
      // Set border color to solid black.
      .strokeColor(Color.BLACK)
      .build()
  }
    
  // Apply the style factory function to the country feature layer.
  countryLayer?.setFeatureStyle(styleFactory)
}

  4. 为所选国家/地区应用红色的填充颜色。只有可见地图项可供点击。

    Java

    @Override
// Define the click event handler.
public void onFeatureClick(FeatureClickEvent event) {
    
  // Get the list of features affected by the click using
  // getPlaceIds() defined below.
  List<String> selectedPlaceIds = getPlaceIds(event.getFeatures());
    
  if (!selectedPlaceIds.isEmpty()) {
    FeatureLayer.StyleFactory styleFactory = (Feature feature) -> {
      // Use PlaceFeature to get the placeID of the country.
      if (feature instanceof PlaceFeature) {
        if (selectedPlaceIds.contains(((PlaceFeature) feature).getPlaceId())) {
          return new FeatureStyle.Builder()
              // Set the fill color to red.
              .fillColor(Color.RED)
              .build();
        }
      }
      return null;
    };
    
    // Apply the style factory function to the feature layer.
    countryLayer.setFeatureStyle(styleFactory);
  }
}
    
// Get a List of place IDs from the FeatureClickEvent object.
private List<String> getPlaceIds(List<Feature> features) {
  List<String> placeIds = new ArrayList<>();
  for (Feature feature : features) {
    if (feature instanceof PlaceFeature) {
        placeIds.add(((PlaceFeature) feature).getPlaceId());
    }
  }
  return placeIds;
}

    Kotlin

    // Define the click event handler.
override fun onFeatureClick(event: FeatureClickEvent) {
    
  // Get the list of features affected by the click using
  // getPlaceIds() defined below.
  val selectedPlaceIds = getPlaceIds(event.getFeatures())
  if (!selectedPlaceIds.isEmpty()) {
      val styleFactory = FeatureLayer.StyleFactory { feature: Feature ->
          // Use PlaceFeature to get the placeID of the country.
          if (feature is PlaceFeature) {
              if (selectedPlaceIds.contains((feature as PlaceFeature).getPlaceId())) {
                  return@StyleFactory FeatureStyle.Builder()
                      // Set the fill color to red.
                      .fillColor(Color.RED)
                      .build()
              }
          }
          return@StyleFactory null
      }
    
      // Apply the style factory function to the feature layer.
      countryLayer?.setFeatureStyle(styleFactory)
  }
}
    
// Get a List of place IDs from the FeatureClickEvent object.
private fun getPlaceIds(features: List<Feature>): List<String> {
  val placeIds: MutableList<String> = ArrayList()
  for (feature in features) {
      if (feature is PlaceFeature) {
          placeIds.add((feature as PlaceFeature).getPlaceId())
      }
  }
  return placeIds
}