Question

我从SD卡读取文件，并在Gridview上显示。

当我从Gridview中选择项目并获取项目的position时。

我点击下载按钮，它将下载该项目。

如何在使用downloadManager时停止项目下载？

代码下载按钮如下：

FileNode file = mFileList.get(temp_position) ;//Get the item I have select from Gridview

                                final String filename = file.mName.substring(file.mName.lastIndexOf("/") + 1) ;
                                final String urlString = "http://" + mIp + file.mName ;

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

                                Uri uri = Uri.parse(urlString) ;
                                DownloadManager.Request request = new Request(uri) ;
                                request.setTitle(filename) ;
                                request.setDescription(urlString) ;

                                String ext = filename.substring(filename.lastIndexOf(".") + 1)
                                        .toLowerCase(Locale.US) ;
                                String mimeType = MimeTypeMap.getSingleton()
                                        .getMimeTypeFromExtension(ext) ;

                                Log.i("MIME", ext + "  ==>  " + mimeType) ;

                                if (mimeType != null) {
                                    request.setMimeType(mimeType) ;
                                }
                                request.allowScanningByMediaScanner() ;

                                request.setNotificationVisibility(Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED) ;

                                request.setDestinationInExternalPublicDir(MainActivity.sAppName, filename) ;

                                downloadManager.enqueue(request) ;

如何在下载文件时停止项目下载？

Answer 1

DownloadManager#enqueue返回long，代表发生下载的id。将long保存在变量中。

然后，如果您需要取消下载，请拨打DownloadManager#remove()传递那么久。

例如

//start a download
long id = downloadManager.enqueue(request);

//stop a download
downloadManager.remove(id);

Answer 2

首先在long id

中保存shared preferences下载请求像这样

SharedPreferences preferenceManager = PreferenceManager.getDefaultSharedPreferences(ACTIVITY CONTEXT);
    Editor PrefEdit = preferenceManager.edit();
    PrefEdit.putLong("Download_ID", id);
    PrefEdit.commit();

现在编写一个自定义broadcast receiver，它会收听点击最近开始的下载。

    public class DownloadManagerBR extends BroadcastReceiver {
        DownloadManager down_m ;
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            down_m = (DownloadManager)context.getSystemService(Context.DOWNLOAD_SERVICE);
            SharedPreferences preferenceManager 
            = PreferenceManager.getDefaultSharedPreferences(context);
            long id = preferenceManager.getLong("Download_ID", 0);
            if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(action)) {

            }
            else if (DownloadManager.ACTION_NOTIFICATION_CLICKED.equals(action)) {
            //IN THIS SECTION YOU CAN WRITE YOUR LOGIC TO CANCEL DOWNLOAD AS STATED IN ABOVE ANSWER 
              downloadManager.remove(id);
            }
        }
    }

并在Android Manifest中注册您的广播接收器

<receiver android:name=".DownloadManagerBR" >
            <intent-filter>
                <action android:name="android.intent.action.DOWNLOAD_COMPLETE" />
                <action android:name="android.intent.action.DOWNLOAD_NOTIFICATION_CLICKED" />
            </intent-filter>
        </receiver>

如何使用DownloadManager停止在android中下载文件？

2 个答案: