java - Android - 无法解析符号 "R"

Question

stackoverflow 上的许多回复建议导入 R。我做到了 在问这个问题之前，我确保重建/清理我的路径超过 10 次。

以下是我的文件的排列方式:

我们都可以清楚地看到错误位于 MainActivity 文件或 XML 文件之间。

这是 MainActivity 文件的代码，它几乎是 Google 的 git hub 帐户的副本，唯一的错误是它无法识别“R”是什么。

    package com.eatwithme;

/*
 * Copyright (C) 2015 Google Inc. All Rights Reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

import android.content.res.Resources;
import android.net.Uri;
import android.os.Bundle;
import android.text.Html;
import android.text.Spanned;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.eatwithme.activities.SampleActivityBase;
import com.eatwithme.logger.Log;
import com.eatwithme.R;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.PendingResult;
import com.google.android.gms.common.api.ResultCallback;
import com.google.android.gms.location.places.Place;
import com.google.android.gms.location.places.PlaceBuffer;
import com.google.android.gms.location.places.Places;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.LatLngBounds;



public class MainActivity extends SampleActivityBase
        implements GoogleApiClient.OnConnectionFailedListener, GoogleApiClient.ConnectionCallbacks {

    /**
     * GoogleApiClient wraps our service connection to Google Play Services and provides access
     * to the user's sign in state as well as the Google's APIs.
     */
    protected GoogleApiClient mGoogleApiClient;

    private PlaceAutocompleteAdapter mAdapter;

    private AutoCompleteTextView mAutocompleteView;
    private TextView mPlaceDetailsText;

    private static final LatLngBounds BOUNDS_GREATER_SYDNEY = new LatLngBounds(
            new LatLng(-34.041458, 150.790100), new LatLng(-33.682247, 151.383362));

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Set up the Google API Client if it has not been initialised yet.
        if (mGoogleApiClient == null) {
            rebuildGoogleApiClient();
        }

        setContentView(R.layout.activity_main);

        // Retrieve the AutoCompleteTextView that will display Place suggestions.
        mAutocompleteView = (AutoCompleteTextView)
                findViewById(R.id.autocomplete_places);

        // Register a listener that receives callbacks when a suggestion has been selected
        mAutocompleteView.setOnItemClickListener(mAutocompleteClickListener);

        // Retrieve the TextView that will display details of the selected place.
        mPlaceDetailsText = (TextView) findViewById(R.id.place_details);

        // Set up the adapter that will retrieve suggestions from the Places Geo Data API that cover
        // the entire world.
        mAdapter = new PlaceAutocompleteAdapter(this, android.R.layout.simple_list_item_1,
                BOUNDS_GREATER_SYDNEY, null);
        mAutocompleteView.setAdapter(mAdapter);

        // Set up the 'clear text' button that clears the text in the autocomplete view
        Button clearButton = (Button) findViewById(R.id.button_clear);
        clearButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mAutocompleteView.setText("");
            }
        });
    }

    /**
     * Listener that handles selections from suggestions from the AutoCompleteTextView that
     * displays Place suggestions.
     * Gets the place id of the selected item and issues a request to the Places Geo Data API
     * to retrieve more details about the place.
     *
     * @see com.google.android.gms.location.places.GeoDataApi#getPlaceById(com.google.android.gms.common.api.GoogleApiClient,
     * String...)
     */
    private AdapterView.OnItemClickListener mAutocompleteClickListener
            = new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            /*
             Retrieve the place ID of the selected item from the Adapter.
             The adapter stores each Place suggestion in a PlaceAutocomplete object from which we
             read the place ID.
              */
            final PlaceAutocompleteAdapter.PlaceAutocomplete item = mAdapter.getItem(position);
            final String placeId = String.valueOf(item.placeId);
            Log.i(TAG, "Autocomplete item selected: " + item.description);

            /*
             Issue a request to the Places Geo Data API to retrieve a Place object with additional
              details about the place.
              */
            PendingResult<PlaceBuffer> placeResult = Places.GeoDataApi
                    .getPlaceById(mGoogleApiClient, placeId);
            placeResult.setResultCallback(mUpdatePlaceDetailsCallback);

            Toast.makeText(getApplicationContext(), "Clicked: " + item.description,
                    Toast.LENGTH_SHORT).show();
            Log.i(TAG, "Called getPlaceById to get Place details for " + item.placeId);
        }
    };

    /**
     * Callback for results from a Places Geo Data API query that shows the first place result in
     * the details view on screen.
     */
    private ResultCallback<PlaceBuffer> mUpdatePlaceDetailsCallback
            = new ResultCallback<PlaceBuffer>() {
        @Override
        public void onResult(PlaceBuffer places) {
            if (!places.getStatus().isSuccess()) {
                // Request did not complete successfully
                Log.e(TAG, "Place query did not complete. Error: " + places.getStatus().toString());

                return;
            }
            // Get the Place object from the buffer.
            final Place place = places.get(0);

            // Format details of the place for display and show it in a TextView.
            mPlaceDetailsText.setText(formatPlaceDetails(getResources(), place.getName(),
                    place.getId(), place.getAddress(), place.getPhoneNumber(),
                    place.getWebsiteUri()));

            Log.i(TAG, "Place details received: " + place.getName());
        }
    };

    private static Spanned formatPlaceDetails(Resources res, CharSequence name, String id,
                                              CharSequence address, CharSequence phoneNumber, Uri websiteUri) {
        Log.e(TAG, res.getString(R.string.place_details, name, id, address, phoneNumber,
                websiteUri));
        return Html.fromHtml(res.getString(R.string.place_details, name, id, address, phoneNumber,
                websiteUri));

    }


    /**
     * Construct a GoogleApiClient for the {@link Places#GEO_DATA_API} using AutoManage
     * functionality.
     * This automatically sets up the API client to handle Activity lifecycle events.
     */
    protected synchronized void rebuildGoogleApiClient() {
        // When we build the GoogleApiClient we specify where connected and connection failed
        // callbacks should be returned, which Google APIs our app uses and which OAuth 2.0
        // scopes our app requests.
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this, 0 /* clientId */, this)
                .addConnectionCallbacks(this)
                .addApi(Places.GEO_DATA_API)
                .build();
    }

    /**
     * Called when the Activity could not connect to Google Play services and the auto manager
     * could resolve the error automatically.
     * In this case the API is not available and notify the user.
     *
     * @param connectionResult can be inspected to determine the cause of the failure
     */
    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

        Log.e(TAG, "onConnectionFailed: ConnectionResult.getErrorCode() = "
                + connectionResult.getErrorCode());

        // TODO(Developer): Check error code and notify the user of error state and resolution.
        Toast.makeText(this,
                "Could not connect to Google API Client: Error " + connectionResult.getErrorCode(),
                Toast.LENGTH_SHORT).show();

        // Disable API access in the adapter because the client was not initialised correctly.
        mAdapter.setGoogleApiClient(null);

    }


    @Override
    public void onConnected(Bundle bundle) {
        // Successfully connected to the API client. Pass it to the adapter to enable API access.
        mAdapter.setGoogleApiClient(mGoogleApiClient);
        Log.i(TAG, "GoogleApiClient connected.");

    }

    @Override
    public void onConnectionSuspended(int i) {
        // Connection to the API client has been suspended. Disable API access in the client.
        mAdapter.setGoogleApiClient(null);
        Log.e(TAG, "GoogleApiClient connection suspended.");
    }

}

此外，这是我的 Android list 文件(删除了我的 key )。请注意我的 Activity 名称。我这样做是因为如果我删除 Activity 名称前的 com.eatwithme，它会给我一个错误。

    <?xml version="1.0" encoding="UTF-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.google.playservices.placecomplete"
    android:versionCode="1"
    android:versionName="1.0">
<uses-sdk
    android:minSdkVersion="14"
    android:targetSdkVersion="19"/>

<!-- PlacePicker also requires OpenGL ES version 2 -->
<uses-feature
    android:glEsVersion="0x00020000"
    android:required="true"/>

<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>

<application
    android:allowBackup="true"
    android:label="@string/app_name"
    android:icon="@mipmap/ic_launcher"
    android:theme="@style/AppTheme">

    <meta-data
        android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version"/>

    <meta-data
        android:name="com.google.android.geo.API_KEY"
        android:value="AnLE"/>

    <activity
        android:name="com.eatwithme.MainActivity"
        android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
</application>

我个人已经尽力了，但遗憾的是，我无法解决这个冲突。在我看来，唯一的三个错误来源可能是

1) 没有R文件

2) AndoridManifest 文件不对

3) 主文件不对 4) 文件顺序不对

关于这个问题有什么指导吗？

Answer 1

问题出在您的 xml list 中:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
Wrong --> package="com.example.google.playservices.placecomplete"
android:versionCode="1"
android:versionName="1.0">

它需要是您项目的确切包名称，即:

package="com.eatwithme"

不是 google 示例包名称。