0
我想設置一個ListView使用ArrayList,但是當我運行我遇到的錯誤的應用程序不幸的是,應用程序已停止。 這裏採用的是Android監視器錯誤:使用ArrayList來設置ListView - null對象引用錯誤
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference at com.example.nfp.weather_g.MainActivity.onCreate(MainActivity.java:35)
,這是我的代碼:
package com.example.nfp.weather_g;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
List<String> forecast = new ArrayList<>();
forecast.add("Today - Sunny - 88/63");
forecast.add("Tomorrow - Foggy - 70/40");
forecast.add("Weds - Cloudy - 72/63");
forecast.add("Thurs - Asteroids - 75/65");
forecast.add("Fri - Heavy Rain - 65/56");
forecast.add("Sat - HELP TRAPPED IN WEATHERSTATION - 60/51");
forecast.add("Sun - Sunny - 80/68");
ArrayAdapter<String> arrayAdapter = new ArrayAdapter(
getApplication(),
android.R.layout.simple_list_item_1,
forecast
);
ListView listView = (ListView) findViewById(android.R.id.list);
listView.setAdapter(arrayAdapter);}}
而且ListView控件ID是列表
我應該怎麼解決呢?