[英]how to access downloads folder in android?
我是新的 android,我正在制作一個應用程序,可以在其中下載文件到下載文件夾(使用下載管理器)。 如果我轉到模擬器中的下載文件夾,我可以看到圖片。 因此,如果我想顯示下載文件的幻燈片,我如何才能訪問該文件夾? 其次如何向此代碼添加進度條:--
import java.util.Arrays;
import android.app.Activity;
import android.app.DownloadManager;
import android.app.DownloadManager.Query;
import android.app.DownloadManager.Request;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
public class Download_managerActivity extends Activity {
private long quueue_for_url;
private DownloadManager dm;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.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);
Query query = new Query();
query.setFilterById(quueue_for_url);
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 uri_String_abcd = c
.getString(c
.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
view.setImageURI(Uri.parse(uri_String_abcd));
}
}
}
}
};
registerReceiver(receiver, new IntentFilter(
DownloadManager.ACTION_DOWNLOAD_COMPLETE));
}
public void onClick(View view) {
dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
Request request_for_url = new Request(
Uri.parse("http://fc03.deviantart.net/fs14/i/2007/086/9/1/Steve_Jobs_portrait_by_tumb.jpg"));
Request request_for_url1 = new Request(
Uri.parse("http://2.bp.blogspot.com/_q7Rxg4wqDyc/S5ZRVLxVYuI/AAAAAAAAAvU/fQAUZ2XFcp8/s400/katrina-kaif.jpg"));
Request request_for_url2 = new Request(
Uri.parse("http://www.buzzreactor.com/sites/default/files/Bill-Gates1.jpg"));
quueue_for_url = dm.enqueue(request_for_url);
quueue_for_url = dm.enqueue(request_for_url1);
quueue_for_url = dm.enqueue(request_for_url2);
}
public void showDownload(View view) {
Intent i = new Intent();
//try more options to show downloading , retrieving and complete
i.setAction(DownloadManager.ACTION_VIEW_DOWNLOADS);
startActivity(i);
}
}
我想添加一個按鈕,該按鈕執行從下載文件夾中拍攝圖片的功能,然后像幻燈片一樣顯示。
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="cmpe235.lab1"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="9" />
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".Download_managerActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
main.xml:-
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button android:text="Start Download" android:id="@+id/button1"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal|center" android:textColor="#0000A0"
android:typeface="serif" android:onClick="onClick"></Button>
<Button android:text="View Downloads" android:id="@+id/button2"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal|center" android:textColor="#0000A0"
android:typeface="serif" android:onClick="showDownload"></Button>
<ImageView android:layout_height="wrap_content" android:id="@+id/imageView1"
android:src="@drawable/icon" android:layout_width="wrap_content"></ImageView>
</LinearLayout>
對於你的第一個問題嘗試
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
(自 API 8 起可用)
要訪問此目錄中的單個文件,請使用File.list()或File.listFiles() 。 似乎只能在通知中報告下載進度,請參閱此處。
您需要在 manifest.xml 文件中設置此權限
android.permission.WRITE_EXTERNAL_STORAGE
getExternalStoragePublicDirectory()
已棄用。
要從Fragment
獲取下載文件夾,
val downloadFolder = requireContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)
從Activity
,
val downloadFolder = getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)
downloadFolder.listFiles()
將列出File
s。
downloadFolder?.path
會給你下載文件夾的字符串路徑。
更新:
在最新版本的 Android 中,對存儲的直接文件系統訪問受到限制。
context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)
為您提供目錄/emulated/0/Android/data/{package}/files/Download
。 如果您想擁有公共下載文件夾,請查看 Android 文檔的存儲訪問框架。
如果您使用的是 shell,則下載(無“s”)文件夾的文件路徑為
/storage/emulated/0/Download
您應該添加下一個權限:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
然后這里是代碼中的用法:
val externalFilesDir = context.getExternalFilesDir(DIRECTORY_DOWNLOADS)
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