如何在android设备中查找所有文件并将它们放在列表中？

Question

I looking for help to list all files in android external storage device. I want to look up in all the folders including the subfolders for the main folder. Is there any way to this?

I have worked on a basic one but still haven't get the desired result. It doesn't work. Here is my code:

File[] files_array;
files_array = new File(Environment.getExternalStorageDirectory().getAbsolutePath()).listFiles();

Please help. Thank you.

Edit:

This method returns 0 size. I don't know what is the matter. This is my activity:

public class Main extends ListActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        List<File> files = getListFiles(Environment.getExternalStorageDirectory());
        setListAdapter(new ArrayAdapter<File>(Main.this, android.R.layout.simple_list_item_1, files));
        Toast.makeText(this, "" + files.size(), Toast.LENGTH_LONG).show();
    }

    private List<File> getListFiles(File parentDir) {
        // On first call, parentDir is your sdcard root path
        ArrayList<File> inFiles = new ArrayList<File>(); // initialize an array list to store file names
        File[] files = parentDir.listFiles(); // list all files in this directory
        for (File file : files) {
            if (file.isDirectory()) { // if the file is a directory
                inFiles.addAll(getListFiles(file)); // **CALL THIS RECURSIVELY TO GET ALL LOWER LEVEL FILES**
            } 

        }
        return inFiles;
    }
}

Answer 1

public void Search_Dir(File dir) {
    String pdfPattern = ".pdf";

    Log.d("check",
            "Environment.getExternalStorageDirectory()------"
                    + dir.getName());

    File FileList[] = dir.listFiles();
    Log.d("check",
            "filelist length---- "
                    + FileList.length);

    if (FileList != null) {
        for (int i = 0; i < FileList.length; i++) {

            if (FileList[i].isDirectory()) {
                Search_Dir(FileList[i]);
            } else {

                Log.d("check",
                        "for check from .pdf---- "
                                + FileList[i].getName());
                if (FileList[i].getName().endsWith(pdfPattern)) {
                    // here you have that file.
                    pdfArrayList.add(FileList[i].getPath());

                }
            }
        }
    }

}

Answer 2

Conceptually, what you are doing is not complete. Your code only gives you a File for the root level directory. To determine all the files within this directory and the sub directories, you need recursive calls so that all the files are listed to the end of the folder levels.

private List<File> getListFiles(File parentDir) {
    // On first call, parentDir is your sdcard root path
    ArrayList<File> inFiles = new ArrayList<File>(); // initialize an array list to store file names
    File[] files = parentDir.listFiles(); // list all files in this directory
    for (File file : files) {
        if (file.isDirectory()) { // if the file is a directory
            inFiles.addAll(getListFiles(file)); // **CALL THIS RECURSIVELY TO GET ALL LOWER LEVEL FILES**
        } 

    }
    return inFiles;
}

Now call this function as:

getListFiles(Environment.getExternalStorageDirectory());

Now, you can add your ArrayList as a source to a List Control.

Bonus : If you would like to represent list the files in a tree like view, I would recommend you to look at https://code.google.com/p/tree-view-list-android/

Source: List all the files from all the folder in a single list

Search all .pdf file present in the Android device

Answer 3

I have found a solution somewhere on the web and I asked my self why not share it.

        public void walkdir(File dir) {

        File[] listFile;
        listFile = dir.listFiles();

        if (listFile != null) {
            for (int i = 0; i < listFile.length; i++) {
                if (listFile[i].isDirectory()) {
                    walkdir(listFile[i]);
                } else {
                  if (listFile[i].getName().toLowerCase().endsWith(".pdf")){
                      files_list.add(listFile[i]);
                  }
                }
            }
        }    
    }

All what you need actually is calling the method above with the parent dir that you want to start with. I recommend to put Environment.getExternalStorageDirectory() in the parent directory so it will not change with different devices.

Answer 4

Can you please try with this: The java.io package has been reimplemented within Android. You are able to use the same mechanisms in Android as you do in Java.

File fileList = new File("/sdcard"); // path which you want to read
if (fileList != null){
    File[] files = fileList.listFiles();
        for (File f : files){
            //Do something with the files
        }
    }
}

Answer 5

I used this code, hope it helps:

    private File[] listOfDir;

    ...

    TextView tv = (TextView) rootView.findViewById(R.id.textView1);
    listOfDir = show();
    String temp = "";
    if (listOfDir != null) {
        for (File i : listOfDir) {
            temp += i.getName() + '\n';
        }
    } else {
        temp = "null";
    }
    tv.setText(temp);
    ...

  public File[] show() {
    File[] dirs = null;
    File dir = new File(*your path*);
    dirs = dir.listFiles();
    return dirs;
}

and just call show to get list all the name

Answer 6

I think this will help. First you need to fetch the contents of the sd card as shown below:

public class FileList extends ListActivity 
{
private File file;
private List<String> myList;

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);

    myList = new ArrayList<String>();   

    String root_sd = Environment.getExternalStorageDirectory().toString();
    file = new File( root_sd + "/external_sd" ) ;       
    File list[] = file.listFiles();

    for( int i=0; i< list.length; i++)
    {
            myList.add( list[i].getName() );
    }

    setListAdapter(new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, myList ));

}

Now that you have all the files and folders from your sdcard in your listview , whenever, you go into a folder, then you need to fetch the contents of that folder as shown below:

protected void onListItemClick(ListView l, View v, int position, long id) 
{
    super.onListItemClick(l, v, position, id);

    File temp_file = new File( file, myList.get( position ) );  

    if( !temp_file.isFile())        
    {
        file = new File( file, myList.get( position ));
        File list[] = file.listFiles();

        myList.clear();

        for( int i=0; i< list.length; i++)
        {
            myList.add( list[i].getName() );
        }
        Toast.makeText(getApplicationContext(), file.toString(), Toast.LENGTH_LONG).show(); 
        setListAdapter(new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, myList ));

    }

}

And again on pressing back you need to load back the contents of your previous folder as shown below:

@Override
public void onBackPressed() {
            String parent = file.getParent().toString();
            file = new File( parent ) ;         
            File list[] = file.listFiles();

            myList.clear();

            for( int i=0; i< list.length; i++)
            {
                myList.add( list[i].getName() );
            }
            Toast.makeText(getApplicationContext(), parent,          Toast.LENGTH_LONG).show(); 
            setListAdapter(new ArrayAdapter<String>(this,
                    android.R.layout.simple_list_item_1, myList ));


    }

I think this is what you need.

Answer 7

Wrote a tutorial on this a while ago. Still use this from time to time. Have a look, you might find what you need. playing-with-sdcard-in-android

Try this: If you don't want directory to be listed put files.add(file1[i]); line in else block

public class MainActivity extends ListActivity {
ArrayList<File> files = new ArrayList<File>();
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    File file[] = Environment.getExternalStorageDirectory().listFiles();
    recursiveFileFind(file);

    setListAdapter(new ArrayAdapter<File>(MainActivity.this,
            android.R.layout.simple_list_item_1, files));
    Toast.makeText(this, "" + files.size(), Toast.LENGTH_LONG).show();
}

public void recursiveFileFind(File[] file1) {
    int i = 0;
    String filePath = "";
    if (file1 != null) {
        while (i != file1.length) {
            filePath = file1[i].getAbsolutePath();
            files.add(file1[i]);
            if (file1[i].isDirectory()) {
                File file[] = file1[i].listFiles();
                recursiveFileFind(file);
            }else{
                            }

            i++;
            Log.d(i + "", filePath);
        }
    }
}

}