retrofit 上传头像

@POST("SchoolApi/Paper/save_audio")
@Multipart
ObservablesaveVoice(
        @Part("uid") String uid,
        @Part("type") String type,
        @Part("test_id") String test_id,
        @Part("tq_id") String tq_id,
        @Part("num") String num,

@Part MultipartBody.Part file);

/**
*  获取保存录音的part
*/
public static MultipartBody.Part getPart(String path){
    File file = new File(path);
    RequestBody requestFile =
            RequestBody.create(MediaType.parse("multipart/form-data"), file);
    MultipartBody.Part part =
            MultipartBody.Part.createFormData("avatar", file.getName(), requestFile);
    return part;

}