Android 下载管理器进度

Android下载管理器是一种非常常见的功能，它可以帮助我们管理和控制应用程序中的下载任务。无论是下载图片、音乐、视频还是其他类型的文件，下载管理器都可以提供方便的接口和功能来监控下载进度、暂停和恢复下载任务等操作。本文将介绍如何使用Android下载管理器来实现下载任务的进度监控，并提供一个案例代码来帮助读者更好地理解和应用这一功能。

xml

java
DownloadManager downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
Uri uri = Uri.parse("http://example.com/file.jpg");
DownloadManager.Request request = new DownloadManager.Request(uri);
long downloadId = downloadManager.enqueue(request);

java
BroadcastReceiver receiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(action)) {
            long downloadId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);
            if (downloadId != -1) {
                DownloadManager.Query query = new DownloadManager.Query();
                query.setFilterById(downloadId);
                Cursor cursor = downloadManager.query(query);
                if (cursor.moveToFirst()) {
                    int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
                    int status = cursor.getInt(columnIndex);
                    if (status == DownloadManager.STATUS_SUCCESSFUL) {
                        // 下载成功
                    } else if (status == DownloadManager.STATUS_FAILED) {
                        // 下载失败
                    } else if (status == DownloadManager.STATUS_PAUSED) {
                        // 下载暂停
                    } else if (status == DownloadManager.STATUS_RUNNING) {
                        // 正在下载
                        int totalSizeIndex = cursor.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES);
                        int downloadedIndex = cursor.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR);
                        int totalSize = cursor.getInt(totalSizeIndex);
                        int downloaded = cursor.getInt(downloadedIndex);
                        int progress = (downloaded * 100) / totalSize;
                        // 更新下载进度
                    }
                }
                cursor.close();
            }
        }
    }
};
registerReceiver(receiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));