在Android中进行Recycleview时无法启动活动错误
我正在使用RecycleView开发应用程序。我收到一条错误消息在Android中进行Recycleview时无法启动活动错误,android,android-layout,android-recyclerview,Android,Android Layout,Android Recyclerview,我正在使用RecycleView开发应用程序。我收到一条错误消息 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.appname/com.app.appname.SpeedDialViewActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widg
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.appname/com.app.appname.SpeedDialViewActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setLayoutManager(android.support.v7.widget.RecyclerView$LayoutManager)' on a null object reference
我的代码如下所示
SpeedDialViewActivity.java
public class SpeedDialViewActivity extends AppCompatActivity {
private List<Bean> beanList = new ArrayList<>();
private RecyclerView recyclerView;
private ViewAdapter mAdapter;
Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_speed_dial_view);
mAdapter = new ViewAdapter(beanList);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(mAdapter);
prepareData();
}
private void prepareData() {
DatabaseHandler handler = new DatabaseHandler(getApplicationContext());
Log.d("Reading: ", "Reading all contacts..");
List<Bean> contacts = handler.getAllContacts();
for (Bean cn : contacts) {
String log = "Id: " + cn.getId() + " ,Name: " + cn.getName() + " ,Phone: " + cn.getNumber();
// Writing Contacts to log
//Log.d("Name: ", log);
cn = new Bean(cn.getName(), cn.getNumber(), cn.getSpeeddial());
beanList.add(cn);
}
}
}
我不知道如何解决这个错误。我错过了
recyclerView=(recyclerView)findViewById(R.id.your\u recyclerView\u id) 您刚刚错过了回收视图的findViewById
recyclerView = (RecyclerView) findViewById(R.id.your_recyclerview_id);
您错过了
recyclerView=(recyclerView)findViewById(R.id.your\u recyclerView\u id)代码>在设置管理器之前,请将u储存如此之多。问题已解决。可能重复的
recyclerView = (RecyclerView) findViewById(R.id.your_recyclerview_id);