如何列出Android设备内部目录中指定文件夹中的文件

Question

我需要显示目录 示例中 指定文件夹中的文件 ，根路径为Directory：/ sdcard / GDM /如何从该文件夹中列出文件。

Answer 1

The File class provides you with a list() method:

Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname. If this abstract pathname does not denote a directory, then this method returns null. Otherwise an array of strings is returned, one for each file or directory in the directory. Names denoting the directory itself and the directory's parent directory are not included in the result. Each string is a file name rather than a complete path.

There is no guarantee that the name strings in the resulting array will appear in any specific order; they are not, in particular, guaranteed to appear in alphabetical order.

So, the code will be something like:

File root = new File("/sdcard/GDM");
String[] files = root.list();  
if( files != null ){
 // do something
}  

Update(s):
To get the size of the file, you will need the length() method. This will return the size in bytes. If you want to get it in MBs, you will need to divide it by 1024*1024

File f = new File("/path/to/some/file");
double sizeInMb = f.length() / (1024*1024);

Answer 2

To get list of files from your sdcard,

List<File> listFilesRoot = getFilesFromRoot(new File("YOUR PATH"));


private List<File> getFilesFromRoot(File parentDir) {
        ArrayList<File> listFiles = new ArrayList<File>();
        File[] files = parentDir.listFiles();
        for (File file : files) {
            if (!file.isDirectory())  {
                    listFiles.add(file);
            }
        }
        return listFiles;
    }