完全參考這三篇：
DownloadManagerAndroid DownloadManager 的使用
[Android] DownloadManager 下載APK並自動開啟安裝畫面(Android6.0 7.0 皆可運作)
progressBar的部分可以參考我這篇 ProgressBar
重點程式碼：
private DownloadManager mDownloadManager;//驅動
private DownloadManager.Request request;//回傳下載網址使用
private DownloadManager.Query query;//監測下載狀態使用
private long downloadID;//下載後給下載的東西一個ID方便後續處理
可以一開始就幫 mDownloadManager初始化。
mDownloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
DownloadManager.Request
Request顧名思義就是請求，作用就是你塞給他一個Uri 在吐給DownloadManager。就開始下載。
request = new DownloadManager.Request(uri);
request.setTitle("HelloWorld");//設置你在下載時，上面的title名稱
request.setDescription("DownLoad Waiting.....");//設置你在下載時，Title旁邊的文字顯示
LatestDownloadID = mDownloadManager.enqueue(request);//裝入DownloadManager並開始下載(同時裝入LatestDownloadID,供query使用抓取你下載的ID)
DownloadManager.Query
query顧名思義就是詢問，作用是給你拿來監控下載的狀態用的。
他只有兩個方法可以使用
query.setFilterById(LatestDownloadID);//用於你要監控的下載ID元件 query.setFilterByStatus(DownloadManager.STATUS_SUCCESSFUL);//你想要監控的下載狀態
基本使用方式：
完全複製Android DownloadManager 的使用這篇的使用方式。
使用Download來下載
// uri 是你的下載地址，可以使用Uri.parse("http://")包裝成Uri對象
DownloadManager.Request req = new DownloadManager.Request(uri);
// 通過setAllowedNetworkTypes方法可以設置允許在何種網絡下下載，
// 也可以使用setAllowedOverRoaming方法，它更加靈活
req.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI);
// 此方法表示在下載過程中通知欄會一直顯示該下載，在下載完成後仍然會顯示，
// 直到用戶點擊該通知或者消除該通知。還有其他參數可供選擇
req.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
// 設置下載文件存放的路徑，同樣你可以選擇以下方法存放在你想要的位置。
// setDestinationUri
// setDestinationInExternalPublicDir
req.setDestinationInExternalFilesDir(this, Environment.DIRECTORY_DOWNLOADS, title);
// 設置一些基本顯示信息
req.setTitle("Android.apk");
req.setDescription("下載完後請點擊打開");
req.setMimeType("application/vnd.android.package-archive");
// Ok go!
DownloadManager dm = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
long downloadId = dm.enqueue(req);
獲取下載的文件
DownloadManager dm = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
DownloadManager.Query query = new DownloadManager.Query().setFilterById(downloadId);
Cursor c = dm.query(query);
if (c != null) {
if (c.moveToFirst()) {
String fileUri = c.getString(c.getColumnIndexOrThrow(DownloadManager.COLUMN_LOCAL_URI));
// TODO 處理文件
}
c.close();
}
實作：
給權限<uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
main_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.update.a015865.downloaddemo.MainActivity">
<Button
android:id="@+id/tv_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="download"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="@+id/tv_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
tools:layout_editor_absoluteX="8dp"
tools:layout_editor_absoluteY="8dp" />
<LinearLayout
android:layout_alignParentBottom="true"
android:id="@+id/tv_layout_progress"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:visibility="gone">
<TextView
android:id="@+id/tv_txtprogress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="0%" />
<ProgressBar
android:max="100"
android:id="@+id/tv_progress"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/tv_image" />
</LinearLayout>
</RelativeLayout>
MainActivity.java
public class MainActivity extends AppCompatActivity {
private Button mButton;
private ImageView mImageView;
private ProgressBar mProgressBar;
private LinearLayout mLayoutProgress;
private TextView mTxtProgress;
private long downloadID;
private DownloadManager DM;
private DownloadManager.Request request;
private DownloadManager.Query query;
static final Uri CONTENT_URI = Uri.parse("content://downloads/my_downloads");
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
initSet();
initListener();
}
private void initView() {
mTxtProgress = (TextView) findViewById(R.id.tv_txtprogress);
mLayoutProgress = (LinearLayout) findViewById(R.id.tv_layout_progress);
mProgressBar = (ProgressBar) findViewById(R.id.tv_progress);
mButton = (Button) findViewById(R.id.tv_button);
mImageView = (ImageView) findViewById(R.id.tv_image);
}
private void initSet() {
DM = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);//init 初始化
}
private void initListener() {
mButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {
checkPermission();
} else {
downloadStuff();
}
}
});
}
//開始下載東西
private void downloadStuff() {
mLayoutProgress.setVisibility(View.VISIBLE);
String URL = "https://dl.dropboxusercontent.com/s/kkvs6zw8k50uc8m/android-nougat.png";
request = new DownloadManager.Request(Uri.parse(URL));//把網址給request處理
request.setTitle("ImageAndroid");//設置title
request.setDescription("download please wait...");//設置內容
downloadID = DM.enqueue(request);//GO 開始下載、並記錄下載的id
//註冊DOWNLOAD_COMPLETE-BroadcastReceiver (裡面有使用query，當下載完成，追蹤塞進去的downloadID開啟圖檔)
BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE)) {
query = new DownloadManager.Query();
query.setFilterById(downloadID);
query.setFilterByStatus(DownloadManager.STATUS_SUCCESSFUL);
Cursor cur = DM.query(query);
if (cur != null) {
if (cur.moveToFirst()) {
String urlString = cur.getString(cur.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));
if (!TextUtils.isEmpty(urlString)) {
mImageView.setImageURI(Uri.parse(urlString));
Toast.makeText(context, "download Success", Toast.LENGTH_SHORT).show();
}
}
}
}
}
};
registerReceiver(receiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
//註冊觀察者 (CONTENT_URI為固定參數，不能做改變)
DownloadObserver downloadObserver = new DownloadObserver(null);
getContentResolver().registerContentObserver(CONTENT_URI, true, downloadObserver);
}
//檢查是否有權限
private void checkPermission() {
int readPermission = ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE);
int writePermission = ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
if (readPermission != PackageManager.PERMISSION_GRANTED && writePermission != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1999);
} else {
downloadStuff();
}
}
//權限讀取結果回應
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case 1999:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
downloadStuff();
} else {
Toast.makeText(this, "給予權限才能拿來做事情啊！", Toast.LENGTH_SHORT).show();
}
break;
}
}
//監控ProgessBar
class DownloadObserver extends ContentObserver {
public DownloadObserver(Handler handler) {
super(handler);
}
@Override
public void onChange(boolean selfChange) {
DownloadManager.Query query = new DownloadManager.Query();
query.setFilterById(downloadID);
Cursor cursor = DM.query(query);
if (cursor != null && cursor.moveToFirst()) {
final int totalColumn = cursor.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES);
final int currentColumn = cursor.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR);
int totalSize = cursor.getInt(totalColumn);
int currentSize = cursor.getInt(currentColumn);
float percent = (float) currentSize / (float) totalSize;
final int progress = Math.round(percent * 100);
runOnUiThread(new Runnable() {//確保在UI Thread執行
@Override
public void run() {
mTxtProgress.setText("" + progress + "%");
mProgressBar.setProgress(progress);
}
});
}
}
}
}
DEMO:
https://github.com/nikeru8/download
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