Android 在内存中创建文件夹

Question

有什么办法/是否允许在 Android 的内部存储器中创建文件夹。示例：

- data
-- com.test.app (application's main package)
---databases (database files)
---files (private files for application)
---shared_prefs (shared preferences)

---users (folder which I want to create)

我可以在内存中创建 users 文件夹吗？

Answer 1

我用它在内存中创建文件夹/文件：

File mydir = context.getDir("mydir", Context.MODE_PRIVATE); //Creating an internal dir;
File fileWithinMyDir = new File(mydir, "myfile"); //Getting a file within the dir.
FileOutputStream out = new FileOutputStream(fileWithinMyDir); //Use the stream as usual to write into the file.

Answer 2

如果您希望用户轻松访问您的文件，则不应使用此功能

File newdir= context.getDir("DirName", Context.MODE_PRIVATE);  //Don't do
if (!newdir.exists())
    newdir.mkdirs();

，而是执行以下操作：

要在手机主存储内存（通常是内部存储器）上创建目录，您应该使用以下代码。请注意，Environment.getExternalStorageDirectory()中的ExternalStorage不一定是指SD卡，它返回手机主存储内存

File mediaStorageDir = new File(Environment.getExternalStorageDirectory(), "MyDirName");

if (!mediaStorageDir.exists()) {
    if (!mediaStorageDir.mkdirs()) {
        Log.d("App", "failed to create directory");
    }
}

目录，使用此代码创建的目录将很容易对手机用户可见。另一种方法（首先提到）在位置（/data/data/package.name/app_MyDirName）创建目录，因此普通手机用户将无法轻松访问它，因此您不应该使用它来存储视频/照片等。

您将需要权限，在 AndroidManifest.xml 中

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

Answer 3

context.getDir("mydir", ...);这将创建 your.package/app_mydir/

 /** Retrieve or creates <b>path</b>structure inside in your /data/data/you.app.package/
 * @param path "dir1/dir2/dir3"
 * @return
 */
private File getChildrenFolder(String path) {
            File dir = context.getFilesDir();
    List<String> dirs = new ArrayList<String>(Arrays.<String>asList(path.split("/")));
    for(int i = 0; i < dirs.size(); ++i) {
        dir = new File(dir, dirs.get(i)); //Getting a file within the dir.
        if(!dir.exists()) {
            dir.mkdir();
        }
    }
    return dir;
}

Answer 4

Android改变了他关于存储的安全性，
如需了解更多详情，请观看视频Android 10 的存储访问

你可以在android 10中尝试这个

File mydir = new File(getApplicationContext().getExternalFilesDir("Directory Name").getAbsolutePath());
    if (!mydir.exists())
    {
        mydir.mkdirs();
        Toast.makeText(getApplicationContext(),"Directory Created",Toast.LENGTH_LONG).show();
    }

你的目录路径将在你的应用程序数据中。

Answer 5

  private File createFile(String fName)  {
            String filePath = Environment.getExternalStorageDirectory().getAbsolutePath()+"/" + fName+".wav";
            File newFile = new File(filePath);
            println(":File path = "+newFile+"\n "+filePath);
            if (!newFile.exists()) {
                try {
                    newFile.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                    toastMsg("Unable to Create New File !");
                }
            } else {
                toastMsg("File Already Exists");

            }

            return newFile;

        }

//请求多个权限

private void reqMulPerm(){
        String permissions[]={
                Manifest.permission.ACCESS_BACKGROUND_LOCATION,
                Manifest.permission.ACCESS_FINE_LOCATION,
                Manifest.permission.ACCESS_COARSE_LOCATION,
                Manifest.permission.READ_EXTERNAL_STORAGE,
                Manifest.permission.WRITE_EXTERNAL_STORAGE,
        };

        if(permissions.length!=0){
            ActivityCompat.requestPermissions(this,permissions,1);
        }
    }

Answer 6

File f = new File(Environment.getExternalStorageDirectory(), "FolderName");
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            try {
               Files.createDirectory(Paths.get(f.getAbsolutePath()));
            } catch (IOException e) {
                e.printStackTrace();
                Toast.makeText(getApplicationContext(), e.getLocalizedMessage(), Toast.LENGTH_LONG).show();
            }
        } else {
            f.mkdir();
            f.mkdirs();
            Toast.makeText(getApplicationContext(), f.getPath(), Toast.LENGTH_LONG).show();
        }

Answer 7

//gets path of the directory("imRec") in Android's data folder
File file=new File(getApplicationContext().getExternalFilesDir("imRec").getAbsolutePath());

if (!file.exists()) {  //if directory by that name doesn't exist
    if (!file.mkdirs()) { //we create the directory
          //if still directory doesn't get created ERROR mssg gets displayed
          //which in most cases won't happen
          Toast.makeText(CameraActivity.this, "ERROR", Toast.LENGTH_SHORT).show();          
    }
}