Question

所以，我正在尝试为登录和用户注册应用编写代码。在Snackbar内部，View没有获取任何值并返回nullPoint异常。

response.enqueue(new Callback<ServerResponse>() {
        @Override
        public void onResponse(Call<ServerResponse> call, retrofit2.Response<ServerResponse> response) {
            ServerResponse resp = response.body();
            Snackbar.make(getView(), resp.getMessage(), Snackbar.LENGTH_LONG).show();   //Line 107
            progress.setVisibility(View.INVISIBLE);
        }
        @Override
        public void onFailure(Call<ServerResponse> call, Throwable t) {
            progress.setVisibility(View.INVISIBLE);
            Log.d(Constants.TAG,"failed");
            Snackbar.make(getView(), t.getLocalizedMessage(), Snackbar.LENGTH_LONG).show();
        }
    });

Logcat出现以下错误。

NullPointerException: Attempt to invoke virtual method 'java.lang.String com.example.loginregistration.models.ServerResponse.getMessage()' on a null object reference
 at com.learn2crack.loginregistration.RegisterFragment$1.onResponse(RegisterFragment.java:107)

Answer 1

尝试以下代码

ServerResponse resp = response.body();
       if(resp != null && resp.getMessage() != null){
        Snackbar.make(getView(), resp.getMessage(), Snackbar.LENGTH_LONG).show();   //Line 107
      }
progress.setVisibility(View.INVISIBLE);

Snackbar参数getView（）在onResponse改造方法中为null

1 个答案: