在 java android google map 中显示和更新标记的图标

Question

我以github上的代码（不是我的代码）为例 https://github.com/mitchtabian/Google-Maps-2018/tree/displaying-trip-duration-of-polylines-end

这是我的问题：

• 假设有一些用户（标记）。
• 我想把marker的图标换成网上的另一张图片，但是不行。

我有两个问题：

1. onBeforeClusterItemRendered() 方法不显示图像。 如果我像原始示例一样使用资源中的图像，那么它可以工作。

2. setUpdateMarker() 方法仅更改一个标记上的两个图像，而不是显示每个标记上的图像。

   @Override protected void onBeforeClusterItemRendered(ClusterMarker item, 
   MarkerOptions markerOptions) {
       super.onBeforeClusterItemRendered(item, markerOptions);
       Bitmap mIcon = null ;
       try {
           InputStream in = new URL(item.getIconPath()).openStream();
           mIcon = BitmapFactory.decodeStream(in);
           imageView.setImageBitmap(mIcon);
           Bitmap icon = iconGenerator.makeIcon();
           markerOptions.icon(
              BitmapDescriptorFactory.fromBitmap(icon)).title(item.getTitle());
       } catch (Exception e) {
           e.printStackTrace();
       } 
   } 
   
   public void setUpdateMarker(ClusterMarker clusterMarker) {
       marker = getMarker(clusterMarker);
       if (marker != null) {
           marker.setPosition(clusterMarker.getPosition());
           new DownloadImageTask().execute(clusterMarker.getIconPath());
       } 
   }
   
   private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
   
       @Override
       protected Bitmap doInBackground(String... urls) {
           Bitmap mIcon = null;
           try {
               InputStream in = new URL(urls[0]).openStream();
               mIcon = BitmapFactory.decodeStream(in);
           } catch (Exception e) {
               e.printStackTrace();
           }
           return mIcon;
       }
   
       @Override
       protected void onPostExecute(Bitmap result) {
           if (marker!=null && result != null) {
               Bitmap resizedBitmap = Bitmap.createScaledBitmap(result, 
                   markerWidth, 
                   markerHeight,
                   false);
               marker.setIcon(
                   BitmapDescriptorFactory.fromBitmap(resizedBitmap));
           }
       } 
   }
   

更新：我也展示了这个类的构造函数：

public class MyClusterManagerRenderer extends DefaultClusterRenderer<ClusterMarker> {
    private static final String TAG = " ClusterManagerRenderer";
    private final IconGenerator iconGenerator;
    private final ImageView imageView;
    private final int markerWidth;
    private final int markerHeight;
    private final int padding;
    private Marker marker;


    public MyClusterManagerRenderer(Context context, GoogleMap googleMap,
                                    ClusterManager<ClusterMarker> clusterManager) {

        super(context, googleMap, clusterManager);

        // initialize cluster item icon generator
        iconGenerator = new IconGenerator(context.getApplicationContext());
        imageView = new ImageView(context.getApplicationContext());
        markerWidth = (int) context.getResources().getDimension(R.dimen.custom_marker_image);
        markerHeight = (int) context.getResources().getDimension(R.dimen.custom_marker_image);
        imageView.setLayoutParams(new ViewGroup.LayoutParams(markerWidth, markerHeight));
        padding = (int) context.getResources().getDimension(R.dimen.custom_marker_padding);
        imageView.setPadding(padding, padding, padding, padding);
        iconGenerator.setContentView(imageView);

    }

Answer 1

您可以在 onClusterItemRendered() 方法中使用您的方法。看看这个答案https://stackoverflow.com/a/34029984/7917629

@Override
    protected void onClusterItemRendered(ClusterMarker item, final Marker marker) {
        String imageUrl = item.getImageUri();

        // here you can call your background task
        // or some other option like Glide
        // you put your icon as: 
        // marker.setIcon(BitmapDescriptorFactory.fromBitmap(resizedBitmap));
    }

------ 在此处更新如何使用 glide（我的版本 4.7.1）

   @Override
    protected void onClusterItemRendered(EventMarker clusterItem, final Marker marker) {
        String imageUrl = clusterItem.getImageUri();

        if (imageView != null && imageUrl != null && !imageUrl.isEmpty()) {
            Glide.with(mContext.getApplicationContext())
                    .load(imageUrl)
                    .apply(new RequestOptions()
                            .optionalCircleCrop()
                            .placeholder(R.mipmap.default_event_cover_rounded)
                            .error(R.mipmap.default_event_cover_rounded)
                            .diskCacheStrategy(DiskCacheStrategy.ALL))
                    .into(new SimpleTarget<Drawable>() {
                        @Override
                        public void onResourceReady(@NonNull Drawable resource, @Nullable Transition<? super Drawable> transition) {
                            imageView.setImageDrawable(resource);
                            Bitmap icon = iconGenerator.makeIcon();
                            try {
                                marker.setIcon(BitmapDescriptorFactory.fromBitmap(icon));
                            } catch (Exception e) {
                                Log.d("TAG", "onResourceReady: " + e.getMessage());
                            }
                        }
                    });
        }
    }

您可以通过以下方式更新您的图标： 在 CustomClusterRender 顶部定义一些 Map<String, Marker> markers，在构造函数中对其进行初始化。在你这个marker.setIcon 之后用一些键添加你的标记。添加 markers.put(clusterItem.getId(), marker); 您的自定义集群必须具有唯一的 ID。你的方法将是

public void updateMarker(final String id, String imgUrl) {
        if (markers.size() > 0) {
            if (iconImage != null) {
                Glide.with(mContext.getApplicationContext())
                        .load(imgUrl)
                        .apply(new RequestOptions()
                                .optionalCircleCrop()
                                .placeholder(R.mipmap.default_event_cover_rounded)
                                .error(R.mipmap.default_event_cover_rounded)
                                .diskCacheStrategy(DiskCacheStrategy.ALL))
                        .into(new SimpleTarget<Drawable>() {
                            @Override
                            public void onResourceReady(@NonNull Drawable resource, @Nullable Transition<? super Drawable> transition) {
                                iconImage.setImageDrawable(resource);
                                Bitmap icon = iconGenerator.makeIcon();
                                try {
                                    markers.get(id).setIcon(BitmapDescriptorFactory.fromBitmap(icon));
                                } catch (Exception e) {
                                    Log.d("TAG_SNAP", "onResourceReady: " + e.getMessage() + markers.get(id).getTitle());
                                }
                            }
                        });
            }
        }