如何排序數組/列表並在android中返回結果？

Question

我正在使用可擴展列表視圖來顯示應用程序中的文件夾和文件。 但是，由於我的應用程序允許用戶添加文件，因此列表很混亂。 因此，我的目的是將排序后的列表（以名稱形式）設置為我的子列表。

我知道有Arrays.sort和Collections.sort，但是這兩種方法都是無效的，而不是返回列表。

那我該怎么辦呢？

我的列表：

    private File recordImageFolder = new File (Environment.getExternalStorageDirectory(),"/Record/Image");
    private File recordSoundFolder = new File (Environment.getExternalStorageDirectory(),"/Record/Sound");

    private String[] groups = { "Image", "Sound" };
    private String[][] children = { recordImageFolder.list(), recordSoundFolder.list() };

Answer 1

不用在聲明中初始化這些字段成員，您可以在構造函數或init方法中對其進行初始化，從而允許您使用Arrays.sort(Object[]) ：

private File recordImageFolder;
private File recordSoundFolder;

private String[] groups;
private String[][] children;

public MyClass() {

    recordImageFolder = new File (Environment.getExternalStorageDirectory(),"/Record/Image");
    recordSoundFolder = new File (Environment.getExternalStorageDirectory(),"/Record/Sound");

    String[] recordImages = recordImageFolder.list();
    String[] recordSounds = recordSoundFolder.list();

    Arrays.sort(recordImages);
    Arrays.sort(recordSounds);

    groups = new String[] { "Image", "Sound" };
    children = new String[][] { recordImages, recordSounds };
}