为工程添加上下文菜单（ContextMenu）

    private final int MENU_DEL = Menu.FIRST;
    private final int MENU_MESS = Menu.FIRST+1;
    public void onCreateContextMenu(ContextMenu menu,View view,ContextMenuInfo menuinfo){
        menu.setHeaderTitle("先来这么几个");
        menu.add(Menu.NONE,MENU_DEL,0,R.string.DELETE);
        menu.add(Menu.NONE,MENU_MESS,0,R.string.MESS);
    }
    public boolean onContextItemSelected(MenuItem item){
        AdapterContextMenuInfo info = (AdapterContextMenuInfo)item.getMenuInfo();
        Music ss = allsongs.get(info.position);
        File file = new File(ss.getFileUrl());
        switch(item.getItemId()){
        case MENU_DEL:
            deleteFile(file);
            break;
        case MENU_MESS:
            break;
        default:
            break;
        }
        return true;
        
    }  
    public void deleteFile(File f) {

        if (f.isDirectory()) {
            File[] files = f.listFiles();
            if (files != null && files.length > 0) {
                for (int i = 0; i < files.length; ++i) {
                    deleteFile(files[i]);
                }
            }
        }
        f.delete();
    }