大家好,我是Android的新手,我在Notes应用程序中工作,直到现在我已经完成了主要的相间操作,并从Edittext接收了输入,但是当涉及到将数据保存到SQLite DB时,我的代码出现故障,请您告诉我我做错了什么吗?。
public void saveToDB(View view) {
try {
String subjet = asunto.getText().toString();
String body = cuerpo.getText().toString();
int day = myCalendar.get(Calendar.DAY_OF_MONTH);
int month = myCalendar.get(Calendar.MONTH);
int year = myCalendar.get(Calendar.YEAR);
Note note = new Note(subject,body,day,month,year); // Create an instance of Note class
DBHelper db = new DBHelper(this,"TaskList.db",null,1); // New Instance of DBHelper class
db.InsertIntoTable(note); // pass the newly created Note instance to DBHelper insert method
db.close(); // we close Database
Toast.makeText(this,"Note saved !!",Toast.LENGTH_SHORT).show(); // Notify the user of the operation success
Intent intent = new Intent(FormActivity.this,MainActivity.class); // Lets return to MainActivity again
startActivity(intent);
}
catch (Exception e){
Toast.makeText(this,"Unable to save note",Toast.LENGTH_SHORT).show();
}
}
public Long InsertIntoTable(Note note){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
/* We organize the values in the respective rows */
values.put(col_subject,note.getSubject());
values.put(col_note,note.getBody());
values.put(col_day,note.getDay());
values.put(col_month,note.getMonth());
values.put(col_year, note.getYear());
// Time to insert data to Database
long rowID = db.insert(table_name,null,values);
return rowID;
}
我放了一个Toast,以防万一我的应用崩溃,并查看操作是否成功,但是每次都会失败。
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.itemview,null);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
Note note = noteList.get(i);
viewHolder.asunto.setText(note.getAsunto());
viewHolder.nota.setText(note.getCuerpo());
viewHolder.fecha.setText(note.getDia() + "/" + note.getMes() + "/" + note.getAno());
viewHolder.etiqueta.setText(note.getTag());
}
E / RecyclerView:未连接适配器;跳过布局