Android 无法从总数中减去SharedReference编号
我正在开发一个卡路里应用程序,用户可以输入他们的消费量 然后显示他们还剩下多少卡路里。我为SharedReferences创建了一个xml,用户在其中输入目标数量 问题:获取共享首选项以减去我的列表视图总数 现在,应用程序正在显示总金额。文本视图称之为卡路里总量。而不是显示总希望它显示还押 FragmentHome.javaAndroid 无法从总数中减去SharedReference编号,android,listview,android-fragments,sharedpreferences,android-preferences,Android,Listview,Android Fragments,Sharedpreferences,Android Preferences,我正在开发一个卡路里应用程序,用户可以输入他们的消费量 然后显示他们还剩下多少卡路里。我为SharedReferences创建了一个xml,用户在其中输入目标数量 问题:获取共享首选项以减去我的列表视图总数 现在,应用程序正在显示总金额。文本视图称之为卡路里总量。而不是显示总希望它显示还押 FragmentHome.java public class FragmentHome extends DialogFragment implements View.OnClickListener {
public class FragmentHome extends DialogFragment implements View.OnClickListener {
private TextView caloriesTotal;
private ListView listView;
private LinearLayout mLayout;
ImageButton AddEntrybtn;
CalorieDatabase calorieDB;
Context context;
private int foodCalories;
Button mButton;
//Database
private DatabaseHandler dba;
private ArrayList<Food> dbFoods = new ArrayList<>();
private CustomListViewAdapter foodAdapter;
private Food myFood ;
//fragment
private android.support.v4.app.FragmentManager fragmentManager;
private FragmentTransaction fragmentTransaction;
public FragmentHome() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup
container,Bundle savedInstanceState) {
View myView = inflater.inflate(R.layout.fragment_home, false);
AddEntrybtn = (ImageButton) myView.findViewById(R.id.AddItems);
AddEntrybtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
((appMain) getActivity()).loadSelection(1);
}
});
caloriesTotal = (TextView) myView.findViewById(R.id.tv_calorie_amount);
listView = (ListView) myView.findViewById(R.id.ListId);
refreshData();
return myView;
}
public void refreshData (){
dbFoods.clear();
dba = new DatabaseHandler(getContext());
ArrayList<Food> foodsFromDB = dba.getFoods();
int totalCalorie = dba.totalCalories();
String formattedCalories = Utils.formatNumber(totalCalorie);
//setting the editTexts:
String Prefs="" ;
caloriesTotal.setText("Total Calories: " + formattedCalories );
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = sp.edit();
editor.putString("prefs_key_current_calorie_amount", String.valueOf(Prefs));
editor.apply();
//Loop
for (int i = 0; i < foodsFromDB.size(); i ++){
String name = foodsFromDB.get(i).getFoodName();
String date = foodsFromDB.get(i).getRecordDate();
int cal = foodsFromDB.get(i).getCalories();
int foodId = foodsFromDB.get(i).getFoodId();
Log.v("Food Id", String.valueOf(foodId));
myFood= new Food();
myFood.setFoodId(foodId);
myFood.setFoodName(name);
myFood.setCalories(cal);
myFood.setRecordDate(date);
dbFoods.add(myFood);
}
dba.close();
//setting food Adapter:
foodAdapter = new CustomListViewAdapter(getActivity(),
R.layout.row_item,dbFoods);
listView.setAdapter(foodAdapter);
foodAdapter.notifyDataSetChanged();
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Bundle username = getActivity().getIntent().getExtras();
String username1 = username.getString("Username");
TextView userMain= (TextView) getView().findViewById(R.id.User);
userMain.setText(username1);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.AddItems:
AddEntry addEntry = new AddEntry();
fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.addToBackStack(null);
fragmentTransaction.replace(R.id.FragmentHolder,addEntry)
.commit();
break;
case R.id.action_settings:
Intent preferenceScreenIntent = new Intent(getContext(),
PreferenceScreenActivity.class);
startActivity(preferenceScreenIntent);
break;
}
}
}
公共类FragmentHome扩展DialogFragment实现View.OnClickListener{
私有文本视图卡路里总量;
私有列表视图列表视图;
私人线路布局;
图像按钮加法器;
卡雷达酶卡雷达B;
语境;
私人国际食品公司;
钮扣;
//数据库
专用数据库处理程序dba;
private ArrayList dbFoods=new ArrayList();
私有CustomListViewAdapter foodAdapter;
私人食品;
//碎片
私有android.support.v4.app.FragmentManager FragmentManager;
私人碎片交易;
公共家庭(){
//必需的空公共构造函数
}
@凌驾
创建视图上的公共视图(布局、充气机、视图组
容器,捆绑包savedInstanceState){
视图myView=充气机。充气(R.layout.fragment\u home,false);
AddEntrybtn=(ImageButton)myView.findViewById(R.id.AddItems);
AddEntrybtn.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图arg0){
((appMain)getActivity()).loadSelection(1);
}
});
卡路里总量=(TextView)myView.findViewById(R.id.tv\u卡路里量);
listView=(listView)myView.findViewById(R.id.ListId);
刷新数据();
返回myView;
}
公共数据(){
dbFoods.clear();
dba=newDatabaseHandler(getContext());
ArrayList foodsFromDB=dba.getFoods();
int totalcarrie=dba.totalcarries();
字符串formattedcarries=Utils.formattNumber(总卡路里);
//设置编辑文本:
字符串Prefs=“”;
卡路里总量.setText(“总卡路里:+形成的卡路里”);
SharedReferences sp=PreferenceManager.GetDefaultSharedReferences(上下文);
SharedReferences.Editor=sp.edit();
putString(“prefs\u key\u current\u carorie\u amount”,String.valueOf(prefs));
editor.apply();
//环路
for(int i=0;i
activity_preference.xml
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory android:title="User Settings">
<EditTextPreference
android:title="Daily Calorie Amount"
android:inputType="number"
android:key="@string/prefs_key_daily_calorie_amount"
android:summary="@string/prefs_description_daily_calorie_amount" />
</PreferenceCategory>
</PreferenceScreen>
您可以使用类似的方法从SharedReference保存和检索整数:
savePrefs("calories", totalCalories);
totalCalories = loadPrefs("calories", totalCalories);
//save prefs
public void savePrefs(String key, int value) {
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt(key, value);
editor.apply();
//get prefs
public int loadPrefs(String key, int value) {
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
return sharedPreferences.getInt(key, value);
}
还有许多关于StackOverFlow的类似问题的例子,展示了如何使用SharedReference
下面是一些来自developer.android.com的SharedReferences文档:
这是个愚蠢的问题,但你能检索总热量,减去消耗的热量,然后将结果存储回共享偏好吗?它看起来像是caloriesTotal.setText显示总卡路里,因为您告诉它这样做。将文本设置为字符串+变量formattedCarries。格式化卡路里的定义是UTIL。formatNumber(总卡路里)我还没试过。我不知道如何从共享偏好中获得价值。这就是我想要做的,得到这个值,然后把它恢复到总热量中。这是我第一次使用java开发应用程序。我知道这可能是个愚蠢的问题