android - 使用 ArcGIS 创建离线 map (.mmpk map )

Question

我的目标是创建一个 Android 应用程序，在连接到 Internet 时从 ArcGIS 门户下载 map ，然后离线使用它们。我想使用服务模式，以便以后应用程序可以具有同步功能。我遵循了 ArcGIS 中的教程 here .

我目前卡在下载 map 部分。我希望下载的 map 位于移动 map 包 (.mmpk) 中，但我的下载目录中有一个 package.info 文件，以及一个包含地理数据库和 .mmap 文件的文件夹作为image shown here .根据我的理解，我应该有一个 .mmpk 文件来离线使用它们。

按照教程步骤，我能够(1) 创建离线 map task ，(2) 指定参数，(3) 检查离线功能。但是在步骤(4) 生成并下载离线 map 时，我预计下载的 map 将位于移动 map 包(.mmpk) 中，但事实并非如此；正如我上面提到的图片所示。在步骤(5) 打开并使用离线 map 中，我可以在使用手动传输到设备中的移动 map 包 (.mmpk) 文件时查看离线 map 。我还尝试打开并使用我下载的 (.mmap) 文件，但没有显示 map 。

我的完整代码如下所示:

(1)创建离线 map task

    // Load map from a portal item
    final Portal portal = new Portal("http://www.arcgis.com");
    final PortalItem webmapItem = new PortalItem(portal, "acc027394bc84c2fb04d1ed317aac674");

    // Create map and add it to the view
    myMap = new ArcGISMap(webmapItem);
    mMapView = (MapView) findViewById(R.id.mapView);
    mMapView.setMap(myMap);

    // Create task and set parameters
    final OfflineMapTask offlineMapTask = new OfflineMapTask(myMap);

(2)指定参数

    // Create default parameters
    final ListenableFuture<GenerateOfflineMapParameters> parametersFuture = offlineMapTask.createDefaultGenerateOfflineMapParametersAsync(areaOfInterest);
    parametersFuture.addDoneListener(new Runnable() {
        @Override
        public void run() {
            try {
                final GenerateOfflineMapParameters parameters = parametersFuture.get();

                // Update the parameters if needed
                // Limit maximum scale to 5000 but take all the scales above (use 0 as a MinScale)
                parameters.setMaxScale(5000);

                parameters.setIncludeBasemap(false);

                // Set attachment options
                parameters.setAttachmentSyncDirection(GenerateGeodatabaseParameters.AttachmentSyncDirection.UPLOAD);
                parameters.setReturnLayerAttachmentOption(GenerateOfflineMapParameters.ReturnLayerAttachmentOption.EDITABLE_LAYERS);

                // Request the table schema only (existing features won't be included)
                parameters.setReturnSchemaOnlyForEditableLayers(true);

                // Update the title to contain the region
                parameters.getItemInfo().setTitle(parameters.getItemInfo().getTitle() + " (Central)");

                // Create new item info
                final OfflineMapItemInfo itemInfo = new OfflineMapItemInfo();

                // Override thumbnail with the new image based on the extent
                final ListenableFuture<Bitmap> exportImageFuture = mMapView.exportImageAsync();
                exportImageFuture.addDoneListener(new Runnable() {
                    @Override
                    public void run() {
                        try {

                            Bitmap mapImage = exportImageFuture.get();
                            // Scale to thumbnail size
                            Bitmap thumbnailImage = Bitmap.createScaledBitmap(mapImage, 200, 133, false);
                            // Convert to byte[]
                            ByteArrayOutputStream stream = new ByteArrayOutputStream();
                            thumbnailImage.compress(Bitmap.CompressFormat.JPEG, 50, stream);
                            byte[] thumbnailBytes = stream.toByteArray();
                            stream.close();

                            // Set values to the itemInfo
                            itemInfo.setThumbnailData(thumbnailBytes);
                            itemInfo.setTitle("Water network (Central)");
                            itemInfo.setSnippet(webmapItem.getSnippet()); // Copy from the source map
                            itemInfo.setDescription(webmapItem.getDescription()); // Copy from the source map
                            itemInfo.setAccessInformation(webmapItem.getAccessInformation()); // Copy from the source map
                            itemInfo.getTags().add("Water network");
                            itemInfo.getTags().add("Data validation");

                            // Set metadata to parameters
                            parameters.setItemInfo(itemInfo);

                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                });

(3) 检查离线能力

                final ListenableFuture<OfflineMapCapabilities> offlineMapCapabilitiesFuture =
                        offlineMapTask.getOfflineMapCapabilitiesAsync(parameters);
                offlineMapCapabilitiesFuture.addDoneListener(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            OfflineMapCapabilities offlineMapCapabilities = offlineMapCapabilitiesFuture.get();
                            if (offlineMapCapabilities.hasErrors()) {
                                // Handle possible errors with layers
                                for (java.util.Map.Entry<Layer, OfflineCapability> layerCapability :
                                        offlineMapCapabilities.getLayerCapabilities().entrySet()) {
                                    if (!layerCapability.getValue().isSupportsOffline()) {
                                        showMessage(layerCapability.getKey().getName() + " cannot be taken offline.");
                                        showMessage("Error : " + layerCapability.getValue().getError().getMessage());
                                    }
                                }

                                // Handle possible errors with tables
                                for (java.util.Map.Entry<FeatureTable, OfflineCapability> tableCapability :
                                        offlineMapCapabilities.getTableCapabilities().entrySet()) {
                                    if (!tableCapability.getValue().isSupportsOffline()) {
                                        showMessage(tableCapability.getKey().getTableName() + " cannot be taken offline.");
                                        showMessage("Error : " + tableCapability.getValue().getError().getMessage());
                                    }
                                }
                            } else {
                                // All layers and tables can be taken offline!
                                showMessage("All layers are good to go!");
                            }
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                });

(4)生成并下载离线 map

                String mExportPath = String.valueOf(getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS)) + File.separator + "New";
                showMessage(mExportPath);

                // Create and start a job to generate the offline map
                final GenerateOfflineMapJob generateOfflineJob =
                        offlineMapTask.generateOfflineMap(parameters, mExportPath);

                // Show that job started
                final ProgressBar progressBarOffline = (ProgressBar) findViewById(R.id.progressBarOffline);
                progressBarOffline.setVisibility(View.VISIBLE);

                generateOfflineJob.start();
                generateOfflineJob.addJobDoneListener(new Runnable() {
                    @Override
                    public void run() {

                        // Generate the offline map and download it
                        GenerateOfflineMapResult result = generateOfflineJob.getResult();

                        if (!result.hasErrors()) {

                            showMessage("no error");
                            mobileMapPackage = result.getMobileMapPackage();
                            // Job is finished and all content was generated
                            showMessage("Map " + mobileMapPackage.getItem().getTitle() +
                                    " saved to " + mobileMapPackage.getPath());

                            // Show offline map in a MapView
                            mMapView.setMap(result.getOfflineMap());

                            // Show that job completed
                            progressBarOffline.setVisibility(View.INVISIBLE);
                        } else {

                            showMessage("error");
                            // Job is finished but some of the layers/tables had errors
                            if (result.getLayerErrors().size() > 0) {
                                for (java.util.Map.Entry<Layer, ArcGISRuntimeException> layerError : result.getLayerErrors().entrySet()) {
                                    showMessage("Error occurred when taking " + layerError.getKey().getName() + " offline.");
                                    showMessage("Error : " + layerError.getValue().getMessage());
                                }
                            }
                            if (result.getTableErrors().size() > 0) {
                                for (java.util.Map.Entry<FeatureTable, ArcGISRuntimeException> tableError : result.getTableErrors().entrySet()) {
                                    showMessage("Error occurred when taking " + tableError.getKey().getTableName() + " offline.");
                                    showMessage("Error : " + tableError.getValue().getMessage());
                                }
                            }
                            // Show that job completed
                            progressBarOffline.setVisibility(View.INVISIBLE);
                        }
                    }
                });

(5)打开并使用离线 map

// Create the mobile map package
    final MobileMapPackage mapPackage = new MobileMapPackage(mobileMapPackage.getPath());
    // Load the mobile map package asynchronously
    mapPackage.loadAsync();

    // Add done listener which will invoke when mobile map package has loaded
    mapPackage.addDoneLoadingListener(new Runnable() {
        @Override
        public void run() {
            // Check load status and that the mobile map package has maps
            if(mapPackage.getLoadStatus() == LoadStatus.LOADED && mapPackage.getMaps().size() > 0){
                // Cdd the map from the mobile map package to the MapView
                mMapView.setMap(mapPackage.getMaps().get(0));
            }else{
                // Log an issue if the mobile map package fails to load
                showMessage(mapPackage.getLoadError().getMessage());
            }
        }
    });

我的代码中的 showMessage() 正在显示 Toast。

public void showMessage(String message) {
    Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
}

我担心如果我的 .mmpk 预期是错误的，或者我的步骤在某处出错，因为我还没有完全理解整个过程。这是我第一次在 Android 中使用 ArcGIS map 。我找不到太多示例代码来进行实验，非常感谢能提供帮助的人。

谢谢!

Answer 1

该任务创建了一个分解的移动 map 包，其工作方式与 .mmpk 文件相同。像这样打开它:


final MobileMapPackage mapPackage =
new MobileMapPackage("/data/com.geoinfo.asmasyakirah.arcgis/files/Documents/New");


(如果您无法在那里访问它，您可能希望在 Environment.getExternalStorageDirectory() 而不是 Environment.DIRECTORY_DOCUMENTS 中生成移动 map 包.)

根据 the documentation for the MobileMapPackage constructor :

Creates a new MobileMapPackage from the .mmpk file or exploded mobile map package at the given path.

如果您确实必须将其作为 .mmpk 文件，只需使用用于制作 zip 文件的 Android API 将其压缩并将其命名为 .mmpk 而不是 .zip。