如何在android外部存储目录中创建一个文件夹？

how to create a folder in android External Storage Directory?

提问by SHIDHIN.T.S

I cannot create a folder in android External Storage Directory.

我无法在 android 外部存储目录中创建文件夹。

I have added permissing on manifest,

我在清单上添加了许可，

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

Here is my code:

这是我的代码：

 String Path = Environment.getExternalStorageDirectory().getPath().toString()+ "/Shidhin/ShidhiImages";
  System.out.println("Path  : " +Path );
  File FPath = new File(Path);
  if (!FPath.exists()) {
        if (!FPath.mkdir()) {
            System.out.println("***Problem creating Image folder " +Path );
        }
  }

回答by Dhaval

Do it like this :

像这样做 ：

String folder_main = "NewFolder";

File f = new File(Environment.getExternalStorageDirectory(), folder_main);
if (!f.exists()) {
    f.mkdirs();
}

If you wanna create another folder into that :

如果您想在其中创建另一个文件夹：

File f1 = new File(Environment.getExternalStorageDirectory() + "/" + folder_main, "product1");
if (!f1.exists()) {
    f1.mkdirs();
}

回答by Blackbelt

The difference between mkdirand mkdirsis that mkdirdoes not create nonexistent parent directory, while mkdirsdoes, so if Shidhindoes not exist, mkdirwill fail. Also, mkdirand mkdirsreturns true only if the directory was created. If the directory already exists they return false

mkdir和之间的区别mkdirs是mkdir不会创建不存在的父目录，而mkdirs会创建，所以如果Shidhin不存在，mkdir就会失败。此外，mkdir与mkdirs返回true只有在目录中创建。如果目录已经存在，则返回 false

回答by Pramesh Bhalala

I can create a folder in android External Storage Directory.

我可以在 android 外部存储目录中创建一个文件夹。

I have added permissing on manifest,

我在清单上添加了许可，

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

Here is my code:

这是我的代码：

String folder_main = "Images";

File outerFolder = new File(Environment.getExternalStorageDirectory(), folder_main);

File inerDire = new File(outerFolder.getAbsoluteFile(), System.currentTimeMillis() + ".jpg");

if (!outerFolder.exists()) {

    outerFolder.mkdirs();

}
if (!outerFolder.exists()) {

    inerDire.createNewFile();

}

• outerFolder.mkdirs();// This will create a Folder

• inerDire.createNewFile();// This will create File (For E.g .jpg
  file)

• outerFolder.mkdirs();// 这将创建一个文件夹

• inerDire.createNewFile();// 这将创建文件（例如 .jpg
  文件）

回答by Jorgesys

The use of Environment.getExternalStorageDirectory()now is deprecated since API level 29, the option is using:

从 API 级别 29 起，Environment.getExternalStorageDirectory()的使用现在已被弃用，该选项正在使用：

Context.getExternalFilesDir().

Context.getExternalFilesDir()。

Example:

例子：

void createExternalStoragePrivateFile() {
    // Create a path where we will place our private file on external
    // storage.
    File file = new File(getExternalFilesDir(null), "DemoFile.jpg");

    try {
        // Very simple code to copy a picture from the application's
        // resource into the external file.  Note that this code does
        // no error checking, and assumes the picture is small (does not
        // try to copy it in chunks).  Note that if external storage is
        // not currently mounted this will silently fail.
        InputStream is = getResources().openRawResource(R.drawable.balloons);
        OutputStream os = new FileOutputStream(file);
        byte[] data = new byte[is.available()];
        is.read(data);
        os.write(data);
        is.close();
        os.close();
    } catch (IOException e) {
        // Unable to create file, likely because external storage is
        // not currently mounted.
        Log.w("ExternalStorage", "Error writing " + file, e);
    }
}

void deleteExternalStoragePrivateFile() {
    // Get path for the file on external storage.  If external
    // storage is not currently mounted this will fail.
    File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
    file.delete();
}

boolean hasExternalStoragePrivateFile() {
    // Get path for the file on external storage.  If external
    // storage is not currently mounted this will fail.
    File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
    return file.exists();
}

回答by Pradeep Sheoran

we can Create Folder or Directory on External storage as :

我们可以在外部存储上创建文件夹或目录：

 String myfolder=Environment.getExternalStorageDirectory()+"/"+fname;
     File f=new File(myfolder);
     if(!f.exists())
     if(!f.mkdir()){
     Toast.makeText(this, myfolder+" can't be created.", Toast.LENGTH_SHORT).show();

    }
    else
     Toast.makeText(this, myfolder+" can be created.", Toast.LENGTH_SHORT).show();
}

and if we want to create Directory or folder on Internal Memory then we will do :

如果我们想在内部存储器上创建目录或文件夹，那么我们将执行以下操作：

File folder = getFilesDir(); 
File f= new File(folder, "doc_download"); 
f.mkdir();

But make Sure you have given Write External Storage Permission. And Remember that if you have no external drive then it choose by default to internal parent directory. I'm Sure it will work .....enjoy code

但请确保您已授予写入外部存储权限。请记住，如果您没有外部驱动器，那么它默认选择内部父目录。我确定它会工作.....享受代码

回答by Chris

Try adding

尝试添加

FPath.mkdirs(); (See http://developer.android.com/reference/java/io/File.html)

FPath.mkdirs(); （见http://developer.android.com/reference/java/io/File.html）

and then just save the file as needed to that path, Android OS will create all the directories needed. You don't need to do the exists checks, just set that flag and save. (Also see : How to create directory automatically on SD card

然后根据需要将文件保存到该路径，Android OS 将创建所有需要的目录。您不需要进行存在检查，只需设置该标志并保存即可。（另请参阅：如何在 SD 卡上自动创建目录

回答by pavan paraskar

try {

尝试 {

String filename = "SampleFile.txt"; String filepath = "MyFileStorage";

String 文件名 = "SampleFile.txt"; String 文件路径 = "MyFileStorage";

                FileInputStream fis = new FileInputStream(myExternalFile);
                DataInputStream in = new DataInputStream(fis);
                BufferedReader br =
                        new BufferedReader(new InputStreamReader(in));
                String strLine;
                while ((strLine = br.readLine()) != null) {
                    myData = myData + strLine;
                }
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
          inputText.setText(myData);
            response.setText("SampleFile.txt data retrieved from External Storage...");
        }
    });

    if (!isExternalStorageAvailable() || isExternalStorageReadOnly()) {
        saveButton.setEnabled(false);
    }
    else {
        myExternalFile = new File(getExternalFilesDir(filepath), filename);
    }