Android DownloadManager不下载已下载的文件

我正在使用

DownloadManager

下载我的应用程序文件。 如果我第二次将url放入

DownloadManager

中，它将下载该文件，并在末尾放入一个-1

filename-1.file

。有没有办法不让

DownloadManager

再次下载它？还是我必须自己检查

代码：

private void下载图像（最终列表数据）{
RuntimeExceptionDao-someDao=DatabaseAdapter.getInstance（）.getSomeDao（）；
DownloadManager DownloadManager=（DownloadManager）mContext.getSystemService（Context.DOWNLOAD\u服务）；
for（SomeClass SomeClass:数据）{
DownloadManager.Request=getRequest（someClass）；
someClass.mDownloadId=downloadmanager.enqueue（请求）；
createOrUpdate（someClass）；
}
}
private DownloadManager.Request getRequest（SomeClass SomeClass）{
Uri=Uri.parse（someClass.mImage）；
DownloadManager.Request=新的DownloadManager.Request（uri）；
request.setNotificationVisibility（DownloadManager.request.VISIBILITY\u隐藏）；
request.setVisibleInDownloadsUi（false）；
request.setdestinationnexternalfilesdir（mContext，Environment.DIRECTORY_下载，car.getFileName（））；
返回请求；
}

我就是这样解决的，您必须向下载管理器进行查询，并验证是否已经有具有相同标题的下载。如果没有任何巧合，那么我会创建一个文件，并使用exist函数验证它是否已经在下载目录中。如果没有，我就开始下载

downloadManager = (DownloadManager) getActivity().getSystemService(Context.DOWNLOAD_SERVICE);

gridview.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {

            //Crear objeto file con la ruta
            File ExistingFile =  new File(Environment.getExternalStoragePublicDirectory(
                    Environment.DIRECTORY_DOWNLOADS) + "/" + Archivos.get(position).getNombre());

            //Checar el downloadManager
            Cursor cursor = downloadManager.query( new Query() ); 
            boolean IsInDownloadManager;

            IsInDownloadManager = false;
            for (int i = 0; i < cursor.getCount() ; i++)
            {
                cursor.moveToPosition(i);
                Log.i("Click Grid", "Objetos en download manager [" + String.valueOf(i) + "] " + cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TITLE)));
                if (Archivos.get(position).getNombre().equals(cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TITLE)))){                                          
                    IsInDownloadManager = true;
                    Log.i("Click Grid", "Objeto está en download Manager " + Archivos.get(position).getNombre());
                    break;
                }
            }

            if (IsInDownloadManager){
                //cursor esta aputando a la fila donde se quedó en el ciclo for
                int Status = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
                Log.i("Click Grid", cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)));

                if (Status == DownloadManager.STATUS_SUCCESSFUL){
                    Toast.makeText(getActivity() ,"Abriendo " +  Archivos.get(position).getNombre(), Toast.LENGTH_SHORT).show(); 
                    try { openFile(getActivity(),ExistingFile ); } catch (IOException e) {e.printStackTrace();}
                }else{
                     Toast.makeText(getActivity() ,Archivos.get(position).getNombre() + " ya se está descargando", Toast.LENGTH_SHORT).show();    
                }

            }else{

                if( ExistingFile.exists() ){
                    Toast.makeText(getActivity() ,"Abriendo " +  Archivos.get(position).getNombre(), Toast.LENGTH_SHORT).show();    
                    try { openFile(getActivity(),ExistingFile ); } catch (IOException e) {e.printStackTrace();}
                }else{
                    DescargarArchivo( Archivos.get(position) );
                }
            }

        }});

downloadManager=（downloadManager）getActivity（）.getSystemService（Context.DOWNLOAD\u服务）；
setOnItemClickListener（新的OnItemClickListener（）{
public void onItemClick（AdapterView父视图、视图v、整型位置、长id）{
//在拉鲁塔的档案馆
File ExistingFile=新文件（Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_下载）+“/”+Archivos.get（position.getNombre（））；
//Checar el下载管理器
Cursor=downloadManager.query（newquery（））；
布尔IsInDownloadManager；
IsInDownloadManager=false；
对于（int i=0；i

您的代码在哪里？您可以在每次下载文件之前检查该文件是否已下载。我添加了代码。有什么好办法可以走到这条路吗？它应该是Environment.DIRECTORY\u下载。它类似于/Files/Downloads/

downloadManager = (DownloadManager) getActivity().getSystemService(Context.DOWNLOAD_SERVICE);

gridview.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {

            //Crear objeto file con la ruta
            File ExistingFile =  new File(Environment.getExternalStoragePublicDirectory(
                    Environment.DIRECTORY_DOWNLOADS) + "/" + Archivos.get(position).getNombre());

            //Checar el downloadManager
            Cursor cursor = downloadManager.query( new Query() ); 
            boolean IsInDownloadManager;

            IsInDownloadManager = false;
            for (int i = 0; i < cursor.getCount() ; i++)
            {
                cursor.moveToPosition(i);
                Log.i("Click Grid", "Objetos en download manager [" + String.valueOf(i) + "] " + cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TITLE)));
                if (Archivos.get(position).getNombre().equals(cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TITLE)))){                                          
                    IsInDownloadManager = true;
                    Log.i("Click Grid", "Objeto está en download Manager " + Archivos.get(position).getNombre());
                    break;
                }
            }

            if (IsInDownloadManager){
                //cursor esta aputando a la fila donde se quedó en el ciclo for
                int Status = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
                Log.i("Click Grid", cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)));

                if (Status == DownloadManager.STATUS_SUCCESSFUL){
                    Toast.makeText(getActivity() ,"Abriendo " +  Archivos.get(position).getNombre(), Toast.LENGTH_SHORT).show(); 
                    try { openFile(getActivity(),ExistingFile ); } catch (IOException e) {e.printStackTrace();}
                }else{
                     Toast.makeText(getActivity() ,Archivos.get(position).getNombre() + " ya se está descargando", Toast.LENGTH_SHORT).show();    
                }

            }else{

                if( ExistingFile.exists() ){
                    Toast.makeText(getActivity() ,"Abriendo " +  Archivos.get(position).getNombre(), Toast.LENGTH_SHORT).show();    
                    try { openFile(getActivity(),ExistingFile ); } catch (IOException e) {e.printStackTrace();}
                }else{
                    DescargarArchivo( Archivos.get(position) );
                }
            }

        }});