头疼，每次学新知识一开头就报错，就大神解决

Question

package com.example.administrator.myrecycler;

import android.support.v7.app.AlertController;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
   AlertController.RecycleListView recycleListView=findViewById(R.id.recycler_view);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

想学一下recyclerview弄一下布局，根据网上教程也先build中插入了，然后xml也写了，之后到mainactivity中一输入recyclerview就报错，上面关于recyclerview的import也是红的，感觉是alertcontroller的问题，有大神知道怎么解决吗？下面是build的

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.android.support:recyclerview-v7:28.0.0'
    implementation 'com.android.support:cardview-v7:28.0.0'
    implementation 'com.android.support:appcompat-v7:28.0.0'
}

Altercontroller的报错信息是“Android....AlterController”is not public in "android.support.v7.app".cannot be accessed from outside package

布局方面是可以用的

Answer 1

recyclerview可能没有下载下来，看一下这里有没有。

我看你这里都没有导入recyclerview