Google云端硬盘查询不会检索文件 - 仅限第一次

Question

我使用Google Drive API查询文件并检索其元数据。在之前从未安装的设备上运行应用程序时，返回的MetadataBuffer为空（正如我从logcat中看到的那样）。 如果我卸载应用程序并重新安装它，相同的代码会生成带有预期元数据对象的MetaDataBuffer。这种情况发生在我测试过的每一台设备上。我假设它与本地缓存有关。我想知道我的代码中是否遗漏了某些内容，或者我最终应该向Google提出问题 这是完整的代码：

public void setupClient(boolean noProgress) {
    Log.i("drive", "setup client...");
    mGoogleApiClient = new GoogleApiClient.Builder(parent)
            .addApi(Drive.API)
            .addScope(Drive.SCOPE_FILE)
            .addConnectionCallbacks(connectionCallbacks)
            .addOnConnectionFailedListener(connectionFailedListener)
            .build();        
    mGoogleApiClient.connect();
}

private GoogleApiClient.ConnectionCallbacks connectionCallbacks = new GoogleApiClient.ConnectionCallbacks() {
    @Override
    public void onConnected(Bundle bundle) {  
        Log.i("drive", "connected");         
        Filter mime = Filters.eq(SearchableField.MIME_TYPE, MIME_TYPE);
        Filter trashed = Filters.eq(SearchableField.TRASHED, false);
        Query query = new Query.Builder()
                .addFilter(mime)
                .addFilter(trashed)
                .build();
        Drive.DriveApi.query(mGoogleApiClient,query).setResultCallback(metadataCallback);
    }

private ResultCallback<DriveApi.MetadataBufferResult> metadataCallback = new
        ResultCallback<DriveApi.MetadataBufferResult>() {
            @Override
            public void onResult(DriveApi.MetadataBufferResult metadataBufferResult) {                    
                MetadataBuffer buffer = metadataBufferResult.getMetadataBuffer();                                         
                Log.i("drive", String.valueOf(buffer.getCount()));                  
                if (buffer.getCount()>0) {  
                /* this is where it fails:
                   the first time, getCount() is 0. the following times,
                   getCount() is the right number of files in the Drive */
                    Log.i("drive","files found");
                    //do things with metadata...
                } else {                        
                    Log.i("drive","files not found"); 
                    //do other things when there are no files...
                }

            }
        };

Answer 1

本地同步需要一些处理。如果您在完成之前提出请求，则可能会得到不完整的结果。您可以使用requestSync等待同步完成。 （尽管如果已经有正在进行的请求，有时此请求会受到速率限制。我们正在努力改善此行为。）