android - 在 Android 11 中使用下载管理器以及分区存储的影响

Question

我在做什么

• 我正在尝试使用下载管理器将文件下载到设备内部存储
• 内部存储指的是位置 /storage/emulated/0/Android/data/com.example.code/files/Download/Devrath/test.db
• 现在我正在使用下面的模拟器，代码可以正常工作并成功下载文件

问题

1. 分区存储会影响 future 吗？
2. 或者既然下载管理器是一个系统服务，它会继续工作

list

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.code">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:usesCleartextTraffic="true"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Code">
        <activity android:name=".MainActivityTwo">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

渐变

compileSdkVersion 31
    buildToolsVersion "30.0.3"

    defaultConfig {
        applicationId "com.example.code"
        minSdkVersion 16
        targetSdkVersion 31
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

MainActivityTwo

public class MainActivityTwo extends AppCompatActivity {

    private static final int REQUEST_CODE = 100;
    //public static final String imageURL = "http://www.tutorialspoint.com/java/java_tutorial.pdf";
    public static final String imageURL = "http://speedtest.ftp.otenet.gr/files/test10Mb.db";
    // String imageName = "java_tutorial.pdf";

    String filePath = "";
    String imageName = "";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        filePath = getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS).toString()
                .concat(File.separator)
                .concat("Devrath").concat(File.separator);

        imageName = "test.db";

        // storage runtime permission
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CODE);
            }
        }

        Button btnDownloadImage = findViewById(R.id.initiateDownloadId);
        Button chkIfFileExistsId = findViewById(R.id.chkIfFileExistsId);
        btnDownloadImage.setOnClickListener(v -> downloadImage(imageURL, imageName));
        chkIfFileExistsId.setOnClickListener(v -> checkIfFileExists());

    }

    public void downloadImage(String url, String outputFileName) {
        DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
        request.setTitle(imageName);
        request.setDescription("Downloading " + imageName);
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
        request.allowScanningByMediaScanner();
        //request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, outputFileName); // ---> Working
        //request.setDestinationInExternalFilesDir(this, Environment.getExternalStorageDirectory().toString() + File.separator, outputFileName);
        request.setDestinationInExternalFilesDir(this,filePath, outputFileName);
        DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
        manager.enqueue(request);
    }

    private void checkIfFileExists() {

        //-> /storage/emulated/0/Android/data/com.example.code/files/Download/Devrath/test.db
        File mFile = new File(filePath.concat(imageName));
        if(mFile.exists()){
            Toast.makeText(this,"File exists",Toast.LENGTH_LONG).show();
        }else{
            Toast.makeText(this,"File does not exists",Toast.LENGTH_LONG).show();
        }
    }
}

Answer 1

• 我最终使用了应用程序的内部存储...我创建了一个 GitHub 项目。
• 在此处发帖以帮助他人。
• 我有一个完整的工作解决方案

GIT-HUB - Link