尝试添加VectorDrawable时出错

Question

在尝试添加VectorDrawable之后，出现了一个错误，但是当有新的时候重新获得它，请告诉我这是什么问题？

Error:(10, 40) error: cannot find symbol class R
Error:(67, 34) error: package R does not exist
Error:(11, 40) error: cannot find symbol class R
Error:(68, 34) error: package R does not exist
Error:(11, 40) error: cannot find symbol class R
Error:(68, 34) error: package R does not exist
Error:(11, 40) error: cannot find symbol class R
Error:(68, 34) error: package R does not exist
Error:(11, 40) error: cannot find symbol class R
Error:(68, 34) error: package R does not exist
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

Answer 1

这看起来像一个R问题，当R回答“包R不存在”时，你应该读回你运行的命令，看看其中一个函数是否没有引用需要安装的软件包......有时它也会误导你的东西。

Answer 2

package com.example.kroket94.osagroup123.fragments;

enter code here import android.content.Context;     import android.net.Uri;     import android.os.Bundle;     import android.support.v4.app.Fragment;     import android.view.LayoutInflater;     import android.view.View;     import android.view.ViewGroup;     import com.example.kroket94.osagroup123.R;

</**
 * A simple {@link Fragment} subclass.
 * Activities that contain this fragment must implement the
 * {@link FragmentGlavnaya.OnFragmentInteractionListener} interface
 * to handle interaction events.
 * Use the {@link FragmentGlavnaya#newInstance} factory method to
 * create an instance of this fragment.
 */
public class FragmentGlavnaya extends android.app.Fragment {
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";


    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public FragmentGlavnaya() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment FragmentGlavnaya.
     */
    // TODO: Rename and change types and number of parameters
    public static FragmentGlavnaya newInstance(String param1, String param2)    {
        FragmentGlavnaya fragment = new FragmentGlavnaya();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
}

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_fragment_glavnaya, container, false);
    }

2个片段错误“R”