Android studio 找不到符号变量Android Studio 0.8.1
我是android studio的新手,我正在尝试运行这段代码 我的代码:Android studio 找不到符号变量Android Studio 0.8.1,android-studio,Android Studio,我是android studio的新手,我正在尝试运行这段代码 我的代码: package app.sunshine.android.example.com.sunshine; import android.app.Activity; import android.app.ActionBar; import android.app.Fragment; import android.os.Bundle; import android.view.LayoutInflater; import and
package app.sunshine.android.example.com.sunshine;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class MyActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.my, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_my, container, false);
// Create some dummy data for the ListView. Here's a sample weekly
// Represented as "day, whether, high/low"
String[] forecastArray= {
"Today - Sunny - 88/63",
"Tomorrow - Foggy - 70/40",
"Weds - Cloudy - 72/63",
"Thurs - Asteroids - 75/65",
"Fri - Heavy Rain - 65/56",
"Sat - HELP TRAPPED IN WEATHERSTATION - 60/51",
"Sun - Sunny - 80/68"
};
List<String> weekForecast = new ArrayList<String>(
Arrays.asList(forecastArray));
// Now that we have some dummy forecast data, create an ArrayAdapter.
// The ArrayAdapter will take data from a source ( Like our dummy forecast
// use to populate the ListView it's attached to
mforecastAdapter =
new ArrayAdapter<String>(
//The current context( this fragment's parent activity
getActivity(),
// ID of list item layout
R.layout.list_item_forecast,
// ID of the textview to populate
R.id.list_item_forecast_textview,
// Forecast data
weekForecast);
// Get a reference to the LIstView and attach this adpater to it
ListView listView = (ListView) rootView.findViewById(
R.id.listview_forecast);
listView.setAdapter(mForecastAdapter);
return rootView;
}
}
}
package app.sunshine.android.example.com.sunshine;
导入android.app.Activity;
导入android.app.ActionBar;
导入android.app.Fragment;
导入android.os.Bundle;
导入android.view.LayoutInflater;
导入android.view.Menu;
导入android.view.MenuItem;
导入android.view.view;
导入android.view.ViewGroup;
导入android.os.Build;
导入android.widget.ArrayAdapter;
导入android.widget.ListView;
导入java.util.ArrayList;
导入java.util.array;
导入java.util.List;
公共类MyActivity扩展了活动{
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
如果(savedInstanceState==null){
getFragmentManager().beginTransaction()
.add(R.id.container,新的占位符片段())
.commit();
}
}
@凌驾
公共布尔onCreateOptions菜单(菜单){
//为菜单充气;这会将项目添加到操作栏(如果存在)。
getMenuInflater().充气(R.menu.my,menu);
返回true;
}
@凌驾
公共布尔值onOptionsItemSelected(菜单项项){
//处理操作栏项目单击此处。操作栏将
//自动处理Home/Up按钮上的点击,只要
//在AndroidManifest.xml中指定父活动时。
int id=item.getItemId();
if(id==R.id.action\u设置){
返回true;
}
返回super.onOptionsItemSelected(项目);
}
/**
*包含简单视图的占位符片段。
*/
公共静态类占位符片段扩展了片段{
公共占位符片段(){
}
@凌驾
创建视图上的公共视图(布局、充气机、视图组容器、,
Bundle savedInstanceState){
视图根视图=充气机。充气(R.layout.fragment\u my,container,false);
//为ListView创建一些虚拟数据
//表示为“日、是否、高/低”
字符串[]forecastArray={
“今天-晴朗-88/63”,
“明天-多雾-70/40”,
“周三-多云-72/63”,
“周四-小行星-75/65”,
“周五-大雨-65/56”,
“卫星-被困在气象站的救援-60/51”,
“太阳-晴朗-80/68”
};
List weekForecast=新建ArrayList(
Arrays.asList(forecastArray));
//现在我们有了一些虚拟预测数据,创建一个ArrayAdapter。
//ArrayAdapter将从源获取数据(如我们的虚拟预测)
//用于填充其附加到的ListView
mforecastAdapter=
新阵列适配器(
//当前上下文(此片段的父活动
getActivity(),
//列表项布局的ID
R.layout.list\u item\u forecast,
//要填充的textview的ID
R.id.list\u item\u forecast\u textview,
//预测数据
周预测);
//获取对LIstView的引用并将此adpater附加到它
ListView ListView=(ListView)rootView.findViewById(
R.id.listview\u预测);
setAdapter(mForecastAdapter);
返回rootView;
}
}
}
但是我得到了以下错误:找不到符号变量
我尝试清理gradle项目并重新启动android应用程序。
但我仍然遇到这个问题
任何帮助都将不胜感激:)
我正在学习本教程您需要声明mForecastAdapter
public static class PlaceholderFragment extends Fragment {
ArrayAdapter<String> mForecastAdapter;
public PlaceholderFragment() {
}
公共静态类占位符片段扩展片段{
阵列适配器mForecastAdapter;
公共占位符片段(){
}
因为您还没有这样做,所以它无法识别变量mForecastAdapter。希望这有帮助