如何实现点击地图Marker获取并保存对应咖啡馆信息？

This is a common and straightforward feature to add. Here's a step-by-step guide tailored to your existing code:

1. Create a Model Class to Store Cafe Details #

First, define a simple Cafe class to hold all relevant info for each cafe. This makes it easy to attach and retrieve data from markers:

public class Cafe {
    private String name;
    private String address;
    private double latitude;
    private double longitude;
    private String placeId;

    // Constructor
    public Cafe(String name, String address, double latitude, double longitude, String placeId) {
        this.name = name;
        this.address = address;
        this.latitude = latitude;
        this.longitude = longitude;
        this.placeId = placeId;
    }

    // Getters (add setters if needed later)
    public String getName() { return name; }
    public String getAddress() { return address; }
    public double getLatitude() { return latitude; }
    public double getLongitude() { return longitude; }
    public String getPlaceId() { return placeId; }
}

2. Attach Cafe Data to Markers During Parsing #

In your parseLocationResult method (where you add markers to the map), create a Cafe object for each result and attach it to the marker using setTag(). Here's how that might look:

private void parseLocationResult(JSONObject result) throws JSONException {
    JSONArray results = result.getJSONArray("results");
    for (int i = 0; i < results.length(); i++) {
        JSONObject place = results.getJSONObject(i);
        
        // Parse cafe details from the API response
        String name = place.getString("name");
        String address = place.getString("vicinity");
        double lat = place.getJSONObject("geometry").getJSONObject("location").getDouble("lat");
        double lng = place.getJSONObject("geometry").getJSONObject("location").getDouble("lng");
        String placeId = place.getString("place_id");

        // Create a Cafe object with parsed data
        Cafe cafe = new Cafe(name, address, lat, lng, placeId);

        // Add blue marker to the map
        MarkerOptions markerOptions = new MarkerOptions()
                .position(new LatLng(lat, lng))
                .title(name)
                .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_BLUE));

        Marker marker = mMap.addMarker(markerOptions);
        marker.setTag(cafe); // Attach the Cafe object to the marker
    }
}

3. Handle Marker Clicks to Display Info #

Set an OnMarkerClickListener on your GoogleMap instance to detect clicks. Retrieve the attached Cafe object and display its info (e.g., in a dialog or bottom sheet):

// Initialize this after getting your GoogleMap instance (e.g., in onMapReady)
mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
    @Override
    public boolean onMarkerClick(Marker marker) {
        // Get the Cafe object from the marker's tag
        Cafe selectedCafe = (Cafe) marker.getTag();
        
        if (selectedCafe != null) {
            // Show cafe details in a dialog with a save option
            AlertDialog.Builder builder = new AlertDialog.Builder(YourActivity.this);
            builder.setTitle(selectedCafe.getName())
                    .setMessage("Address: " + selectedCafe.getAddress())
                    .setPositiveButton("Save", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            // Save the selected cafe
                            saveSelectedCafe(selectedCafe);
                            Toast.makeText(YourActivity.this, "Cafe saved successfully!", Toast.LENGTH_SHORT).show();
                        }
                    })
                    .setNegativeButton("Close", null)
                    .show();
        }
        return true; // Consume the click event to override default map behavior
    }
});

4. Save the Selected Cafe Information #

Choose a storage method based on your needs. Here are two common options:

Option A: Save to SharedPreferences (for persistent, simple data) #

private void saveSelectedCafe(Cafe cafe) {
    SharedPreferences prefs = getSharedPreferences("CafeStorage", MODE_PRIVATE);
    SharedPreferences.Editor editor = prefs.edit();
    
    editor.putString("saved_name", cafe.getName());
    editor.putString("saved_address", cafe.getAddress());
    editor.putFloat("saved_lat", (float) cafe.getLatitude());
    editor.putFloat("saved_lng", (float) cafe.getLongitude());
    editor.putString("saved_place_id", cafe.getPlaceId());
    
    editor.apply(); // Commit changes
}

// Retrieve saved cafe later:
private Cafe getSavedCafe() {
    SharedPreferences prefs = getSharedPreferences("CafeStorage", MODE_PRIVATE);
    String name = prefs.getString("saved_name", null);
    if (name == null) return null;
    
    String address = prefs.getString("saved_address", "");
    double lat = prefs.getFloat("saved_lat", 0);
    double lng = prefs.getFloat("saved_lng", 0);
    String placeId = prefs.getString("saved_place_id", "");
    
    return new Cafe(name, address, lat, lng, placeId);
}

Option B: Use a Singleton (for in-memory storage during app session) #

public class SavedCafeManager {
    private static SavedCafeManager instance;
    private Cafe savedCafe;

    private SavedCafeManager() {}

    public static synchronized SavedCafeManager getInstance() {
        if (instance == null) {
            instance = new SavedCafeManager();
        }
        return instance;
    }

    public void saveCafe(Cafe cafe) {
        this.savedCafe = cafe;
    }

    public Cafe getSavedCafe() {
        return savedCafe;
    }
}

// Usage in the click listener:
SavedCafeManager.getInstance().saveCafe(selectedCafe);

// Retrieve anywhere in the app:
Cafe savedCafe = SavedCafeManager.getInstance().getSavedCafe();

Quick Notes for Your Existing Code #

• Ensure your parseLocationResult method has access to your GoogleMap instance (mMap in the examples above).
• Double-check that you've initialized Google Maps correctly in your activity/fragment and have the necessary location permissions enabled.

内容的提问来源于stack exchange，提问作者newbieHere