错误：无法的compareTo（）ID

Question

我一直在compareTo部分得到错误：

Error:(38, 36) error: cannot find symbol method compareTo(CharSequence)

Collections.sort(songList, new Comparator<Song>() { 
     public int compare(Song a, Song b) { 
      //this part down below 
      return a.getTitle().compareTo(b.getTitle()); 
     } 

    }); 

Answer 1

更新您的getTitle()方法返回String，而不是CharSequence。

Answer 2

尝试转换的标题为字符串：（。b.getTitle（）的toString（））

return a.getTitle().toString().compareTo(b.getTitle().toString());