Question

我正在做Android的任务。

我从URL下载文件并保存在android手机的内部存储/目录中？我的代码写在下面，但这是外部存储代码，我需要内部存储代码。

 public void onClick(View v) {
                    Toast.makeText(Computer.this,"Please Wait until the file is download",Toast.LENGTH_LONG).show();
                    downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
                    Uri uri = Uri.parse("url");
                    DownloadManager.Request request = new DownloadManager.Request(uri);
                    request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE);
                    request.setAllowedOverRoaming(false);
                    request.setTitle("" + "filename" + ".pdf");
                    request.setVisibleInDownloadsUi(true);
                    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
                    Long reference = downloadManager.enqueue(request);
                    request.setDestinationInExternalFilesDir(Environment.DIRECTORY_DOWNLOADS, "/"+ "filename");
                    refid = downloadManager.enqueue(request);
                    Log.e("OUT", "" + refid);

那是外部存储代码，但我想保存在Android手机的内部存储中。

Answer 1

您不能使用DownloadManager直接下载到your app's portion of internal storage。您将需要use OkHttp或其他一些进程内HTTP客户端API。

Answer 2

您可以使用此：

request.setDestinationUri(Uri.fromFile(new File(context.getCacheDir(),"filename.txt")));

Answer 3

您可以简单地删除此行request.setDestinationInExternalFilesDir()

默认情况下，下载会保存到共享下载缓存中的生成文件名

From Docs

Answer 4

只有您自己的应用可以Access到应用internal storage，默认的android内置下载管理器无法访问您的应用内部存储，因此您无法下载内部存储。

解决方案：

将sd卡中的文件下载为临时文件，下载完成后注册一个接收器，然后在从外部存储器中删除文件后将文件从外部存储器复制到内部存储器中。

完整代码：

public class MainActivity extends Activity {
    private long enqueue;
    private DownloadManager dm;

    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        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, 0);
                    DownloadManager.Query query = new DownloadManager.Query();
                    query.setFilterById(enqueue);
                    Cursor c = dm.query(query);
                    if (c.moveToFirst()) {
                        int columnIndex = c
                                .getColumnIndex(DownloadManager.COLUMN_STATUS);
                        if (DownloadManager.STATUS_SUCCESSFUL == c
                                .getInt(columnIndex)) {

                            ImageView view = (ImageView) findViewById(R.id.imageView1);
                            String uriString = c
                                    .getString(c
                                            .getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));

                            Uri a = Uri.parse(uriString);
                            File d = new File(a.getPath());
                           // copy file from external to internal storage..After that delete file from external storage..Code will easily avalible on google.
                            view.setImageURI(a);
                        }
                    }
                }
            }
        };

        registerReceiver(receiver, new IntentFilter(
                DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }

    public void onClick(View view) {
        dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
        DownloadManager.Request request = new DownloadManager.Request(
                Uri.parse("http://www.vogella.de/img/lars/LarsVogelArticle7.png")).setDestinationInExternalPublicDir("/Sohail_Temp", "test.jpg");
        enqueue = dm.enqueue(request);
    }

    public void showDownload(View view) {
        Intent i = new Intent();
        i.setAction(DownloadManager.ACTION_VIEW_DOWNLOADS);
        startActivity(i);
    }
}

布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onClick"
        android:text="Start Download"></Button>

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="showDownload"
        android:text="View Downloads"></Button>

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/image_1"></ImageView>
</LinearLayout>

权限：

 <uses-permission android:name="android.permission.INTERNET" />
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

在内部存储器中下载PDF文件

4 个答案: