我为我的班级项目创建卡路里应用程序。我试图实现一个数据库来存储用户添加的卡路里信息，这些信息将显示在列表视图中。用户将在add_entry片段中输入卡路里，并显示在listview中的fragment_home页面上。
问题：我不确定是否使用条目添加片段将信息正确添加到数据库，以便在列表视图中显示信息。这是我第一次使用Android Studio / App。
问题2： 出于某些原因，当我点击我的homefragment应用程序上的图像按钮崩溃时 它不会去add_entry片段
logcat的：
04-06 00:33:41.213 30567-30567/com.example.treycoco.calorietracker E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.treycoco.calorietracker, PID: 30567
java.lang.IllegalStateException: Could not find method Click(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatImageButton with id 'AddItems'
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.resolveMethod(AppCompatViewInflater.java:325)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:284)
at android.view.View.performClick(View.java:5697)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7229)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
FragmentHome.java
public class FragmentHome extends Fragment implements
View.OnClickListener {
public static final String ARG_SECTION_NUMBER = "section_number";
public static final String ARG_ID = "_id";
private TextView label;
private int sectionNumber = 0;
private Calendar fragmentDate;
ListView listview;
ImageButton AddEntrybtn;
CalorieDatabase calorieDB;
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, container,
false);
label= (TextView) myView.findViewById(R.id.section_label);
AddEntrybtn = (ImageButton) myView.findViewById(R.id.AddItems);
return myView;
}
@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);
openDataBase();
}
private void openDataBase (){
calorieDB= new CalorieDatabase(getActivity());
calorieDB.open();
}
private void closeDataBase(){
calorieDB.close();
};
private void populateLVFromDB(){
Cursor cursor = calorieDB.getAllRows();
String[] fromFieldNames = new String[]
{CalorieDatabase.KEY_NAME, CalorieDatabase.KEY_CalorieValue};
int[] toViewIDs = new int[]
{R.id.foodEditText, R.id.caloriesEditText, };
SimpleCursorAdapter myCursorAdapter =
new SimpleCursorAdapter(
getActivity(),
R.layout.row_item,
cursor,
fromFieldNames,
toViewIDs
);
listview = (ListView) getActivity().findViewById(R.id.listView);
listview.setAdapter(myCursorAdapter);
}
@Override
public void onResume() {
super.onResume();
// set label to selected date. Get date from Bundle.
int dayOffset = sectionNumber - FragmentHomeDayViewPager.pagerPageToday;
fragmentDate = Calendar.getInstance();
fragmentDate.add(Calendar.DATE, dayOffset);
SimpleDateFormat sdf = new SimpleDateFormat(appMain.dateFormat);
String labelText = sdf.format(fragmentDate.getTime());
switch (dayOffset) {
case 0:
labelText += " (Today)";
break;
case 1:
labelText += " (Tomorrow)";
break;
case -1:
labelText += " (Yesterday)";
break;
}
label.setText(labelText);
}
@Override
public void onDestroy() {
super.onDestroy();
}
@Override
public void onDetach() {
super.onDetach();
startActivity( new Intent(getContext(),MainActivity.class));
}
@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;
}
}
}
CalorieDatabase.java
public class CalorieDatabase {
private static final String TAG = "DBAdapter";
public static final String KEY_ROWID = "_id";
public static final int COL_ROWID = 0;
public static final String KEY_NAME = "Description";
public static final String KEY_CalorieValue = "Calories";
public static final int COL_NAME = 1;
public static final int COL_CalorieValue= 2;
public static final String[] ALL_KEYS = new String[] {KEY_ROWID,
KEY_NAME, KEY_CalorieValue};
public static final String DATABASE_NAME = "CalorieDb";
public static final String DATABASE_TABLE = "Calorie_Info";
public static final int DATABASE_VERSION = 1;
private static final String DATABASE_CREATE_SQL =
"create table " + DATABASE_TABLE
+ " (" + KEY_ROWID + " integer primary key autoincrement, "
+ KEY_NAME + " text not null, "
+ KEY_CalorieValue + " integer not null, "
+ ");";
private final Context context;
private DatabaseHelper myDBHelper;
private SQLiteDatabase db;
public CalorieDatabase(Context ctx) {
this.context = ctx;
myDBHelper = new DatabaseHelper(context);
}
public CalorieDatabase open() {
db = myDBHelper.getWritableDatabase();
return this;
}
public void close() {
myDBHelper.close();
}
public long insertRow(String description, int CalorieVal) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, description);
initialValues.put(KEY_CalorieValue, CalorieVal);
return db.insert(DATABASE_TABLE, null, initialValues);
}
public boolean deleteRow(long rowId) {
String where = KEY_ROWID + "=" + rowId;
return db.delete(DATABASE_TABLE, where, null) != 0;
}
public void deleteAll() {
Cursor c = getAllRows();
long rowId = c.getColumnIndexOrThrow(KEY_ROWID);
if (c.moveToFirst()) {
do {
deleteRow(c.getLong((int) rowId));
} while (c.moveToNext());
}
c.close();
}
public Cursor getAllRows() {
String where = null;
Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS,
where, null, null, null, null, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
public Cursor getRow(long rowId) {
String where = KEY_ROWID + "=" + rowId;
Cursor c = db.query(true, DATABASE_TABLE, ALL_KEYS,
where, null, null, null, null, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
public boolean updateRow(long rowId, String description, int
CalorieValue) {
String where = KEY_ROWID + "=" + rowId;
ContentValues newValues = new ContentValues();
newValues.put(KEY_NAME, description);
newValues.put(KEY_CalorieValue, CalorieValue);
return db.update(DATABASE_TABLE, newValues, where, null) != 0;
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase _db) {
_db.execSQL(DATABASE_CREATE_SQL);
}
@Override
public void onUpgrade(SQLiteDatabase _db, int oldVersion, int
newVersion) {
Log.w(TAG, "Upgrading application's database from version " +
oldVersion
+ " to " + newVersion + ", which will destroy all old
data!");
_db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(_db);
}
}
}
AddEntry.java
public class AddEntry extends Fragment implements
View.OnClickListener {
EditText DescriptionET,CalorieET;
ImageButton savebtn;
String description , calorieAmt;
CalorieDatabase calorieDB;
public AddEntry() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_add_entry, container, false);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
DescriptionET= (EditText)view.findViewById(R.id.foodEditText);
CalorieET=(EditText)view.findViewById(R.id.caloriesEditText);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.SaveBtn:
description = DescriptionET.getText().toString();
calorieAmt=CalorieET.getText().toString();
break;
case R.id.CancelBtn:
break;
}
}
@Override
public void onDestroy() {
super.onDestroy();
}
@Override
public void onDetach() {
super.onDetach();
}
}
答案 0 :(得分：0)
尝试替换此内容，从语句中删除最后的逗号（，）
private static final String DATABASE_CREATE_SQL =
"create table " + DATABASE_TABLE
+ " (" + KEY_ROWID + " integer primary key autoincrement, "
+ KEY_NAME + " text not null, "
+ KEY_CalorieValue + " integer not null "
+ ");";
答案 1 :(得分：0)
从上一个字段中删除,
private static final String DATABASE_CREATE_SQL =
"create table " + DATABASE_TABLE
+ " (" + KEY_ROWID + " integer primary key autoincrement, "
+ KEY_NAME + " text not null, "
+ KEY_CalorieValue + " integer not null "
+ ");";
答案 2 :(得分：0)
private static final String DATABASE_NAME =＆＃34; CalorieDb.db＆＃34;;
然后在oncreat（）
中调用下面的方法public void checkDB() {
try {
//android default database location is : /data/data/youapppackagename/databases/
String packageName = this.getPackageName();
String destPath = "/data/data/" + packageName + "/databases";
String fullPath = "/data/data/" + packageName + "/databases/"
+ DATABASE_NAME;
//this database folder location
File f = new File(destPath);
//this database file location
File obj = new File(fullPath);
//check if databases folder exists or not. if not create it
if (!f.exists()) {
f.mkdirs();
f.createNewFile();
}
//check database file exists or not, if not copy database from assets
if (!obj.exists()) {
this.CopyDB(fullPath);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
Unintall应用程序和清理并重建项目然后我认为解决您的问题。
答案 3 :(得分：-2)
private static final String DATABASE_CREATE_SQL =
" create table " + DATABASE_TABLE
+ " ( " + KEY_ROWID + " integer primary key autoincrement, "
+ KEY_NAME + " text not null, "
+ KEY_CalorieValue + " integer not null, "
+ " ); ";
添加空格“）”