java - Android Studio : can´t resolve symbol R

Question

我知道这个问题已被问过多次，但由于我的上下文，没有任何答案是有用的。问题是，我刚刚打开我的第一个项目(在我的实际计算机中)所有“R”。在mainActivity.java中变成红色。有谁知道这个问题的原因是什么以及如何解决？

这是 .java 主要 Activity

package xyz.elblog.elblog;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebView;
import android.graphics.drawable.Drawable;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.HTTP;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
import android.view.View.OnClickListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import android.widget.FrameLayout;
import android.text.Html;
import android.app.Activity;
public class home extends Activity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        String readJSON = getJSON("http://blogging.mysite.com.mx/json.php");
        try{
            JSONObject jsonObject = new JSONObject(readJSON);
           String seo = jsonObject.getString("seo");
            WebView bprimary = (WebView) findViewById(R.id.bprimary);
            bprimary.loadData(seo,"text/html","UTF-8");
        } catch(Exception e){e.printStackTrace();}
        finally {
            System.out.println("Success");
        }

    }

    public String getJSON(String address){
        StringBuilder builder = new StringBuilder();
        HttpClient client = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(address);
        try{
            HttpResponse response = client.execute(httpGet);
            StatusLine statusLine = response.getStatusLine();
            int statusCode = statusLine.getStatusCode();
            if(statusCode == 200){
                HttpEntity entity = response.getEntity();
                InputStream content = entity.getContent();
                BufferedReader reader = new BufferedReader(new InputStreamReader(content));
                String line;
                while((line = reader.readLine()) != null){
                    builder.append(line);
                }
            } else {
                Log.e(home.class.toString(),"Failedet JSON object");
            }
        }catch(ClientProtocolException e){
            e.printStackTrace();
        } catch (IOException e){
            e.printStackTrace();
        }
        return builder.toString();
    }
}

因此这是 home.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="fill_parent" android:layout_width="fill_parent">

    <FrameLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/bprimary"></FrameLayout>

</LinearLayout>

我正在尝试使用 json html 并在框架布局上显示

构建.gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 19
    buildToolsVersion "23.0.1"

    defaultConfig {
        applicationId "xyz.elblog.elblog"
        minSdkVersion 14
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.0.1'
}

Answer 1

该问题是由于您的 xml 文件中存在一些错误而导致的。因此，请检查所有 xml 布局、样式和选择器是否有错误。还要检查可绘制文件的文件名。就像您在可绘制对象中添加一些图片，其名称中包含“-”等符号一样，这是给出名称的不正确方式。因此，找到错误并重建您的项目。这个问题很容易解决。