Android recyclerView没有';t显示';雷亚尔';我的列表项的数据
我已经实现了一个recyclerView和一个SQLite数据库来保存/检索recyclerView的数据,但是我在recyclerView上获得的数据不是应该显示的数据。在没有SQLite db的情况下,recyclerView正常工作 单击加号时,将弹出一个带有EditText字段的对话框,用户可以在其中键入信息: 这是DialogFragment类,用户应在其中写入信息:Android recyclerView没有';t显示';雷亚尔';我的列表项的数据,android,sqlite,Android,Sqlite,我已经实现了一个recyclerView和一个SQLite数据库来保存/检索recyclerView的数据,但是我在recyclerView上获得的数据不是应该显示的数据。在没有SQLite db的情况下,recyclerView正常工作 单击加号时,将弹出一个带有EditText字段的对话框,用户可以在其中键入信息: 这是DialogFragment类,用户应在其中写入信息: public class DialogAdd extends DialogFragment { private B
public class DialogAdd extends DialogFragment {
private Button okButton;
private EditText name, quantity, location, normalPrice, offerPrice;
private List<ShopListItem> shopListItem;
private Context context;
DatabaseHelper dbHelper;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dbHelper = new DatabaseHelper(getContext());
shopListItem = new ArrayList<>();
context = getActivity();
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.add_productdialog,container, false);
getDialog().setCanceledOnTouchOutside(false);
getDialog().setTitle("Add to shoplist");
name = (EditText) rootView.findViewById(R.id.dialog_productname);
quantity = (EditText) rootView.findViewById(R.id.dialog_qantity);
location = (EditText) rootView.findViewById(R.id.dialog_location);
normalPrice = (EditText) rootView.findViewById(R.id.dialog_normalPrice);
offerPrice = (EditText) rootView.findViewById(R.id.dialog_offerPrice);
okButton = (Button) rootView.findViewById(R.id.dialog_okButton);
okButton.getBackground().setColorFilter(Color.parseColor("#2fbd4b"), PorterDuff.Mode.MULTIPLY);
okButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (name.getText().toString().isEmpty()) {
Toast.makeText(context, "You must add a name", Toast.LENGTH_LONG).show();
} else {
dbHelper.insertData(name.toString() ,quantity.toString(),location.toString(),normalPrice.toString(),offerPrice.toString());
getDialog().dismiss();
}
}
});
return rootView;
}
public class MainActivity extends AppCompatActivity{
private ImageButton addbutton;
private DialogAdd dialogAdd;
public static RecyclerView recyclerView;
private List<ShopListItem> shopListItems;
private SQLiteDatabase db;
private Cursor cursor;
private DatabaseHelper databaseHelper;
private ShoplistAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.shoppinglist_mainactivity);
databaseHelper = new DatabaseHelper(this);
addbutton = (ImageButton) findViewById(R.id.addbtn);
addbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dialogAdd = new DialogAdd();
dialogAdd.show(getSupportFragmentManager(), "addDialog");
}
});
//RecyclerView
recyclerView = (RecyclerView)findViewById(R.id.rv_shoppinglist);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(App.getAppContex());
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(linearLayoutManager);
initializeData();
adapter = new ShoplistAdapter(shopListItems);
recyclerView.setAdapter(adapter);
}
private void initializeData(){
shopListItems = new ArrayList<>();
Cursor resultset = databaseHelper.getAllData();
if (resultset.moveToFirst()){
while(!resultset.isAfterLast()){
shopListItems.add(new ShopListItem(resultset.getString(1), resultset.getString(2), resultset.getString(3), resultset.getString(4), resultset.getString(5)));
resultset.moveToNext();
}
}
resultset.close();
shopListItems.add(new ShopListItem("Potato", "2 KG", "MALL", "7 kr", ""));
}
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME ="dbshoplist.db";
public static final String TABLE_NAME ="product_table";
public static final String COL_ID = "ID";
public static final String COL_NAME ="NAME";
public static final String COL_QTY ="QUANTITY";
public static final String COL_LOCATION ="LOCATION";
public static final String COL_PRICE1 ="PRICE1";
public static final String COL_PRICE2 ="PRICE2";
/*
This constructor creates the database
*/
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
SQLiteDatabase db = this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,QUANTITY TEXT,LOCATION TEXT,PRICE1 TEXT,PRICE2 TEXT)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public boolean insertData(String name, String qty, String location, String price1, String price2){
SQLiteDatabase db = this.getWritableDatabase();
// content value is a row, and we fill it with the put();
ContentValues contentValues = new ContentValues();
contentValues.put(COL_NAME, name);
contentValues.put(COL_QTY, qty);
contentValues.put(COL_LOCATION, location);
contentValues.put(COL_PRICE1, price1);
contentValues.put(COL_PRICE2, price2);
long result = db.insert(TABLE_NAME, null,contentValues);
if(result == -1) {
return false;
}else{
return true;
}
}
public Cursor getAllData(){
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursorResults = db.rawQuery("SELECT * FROM " + TABLE_NAME, null);
return cursorResults;
}
public class ShoplistAdapter extends RecyclerView.Adapter<ShoplistAdapter.ViewHolder>{
List<ShopListItem> shopListItems;
public ShoplistAdapter(List<ShopListItem> shopListItems) {
this.shopListItems = shopListItems;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Context context = parent.getContext();
LayoutInflater inflater = LayoutInflater.from(context);
View shoplist_itemView = inflater.inflate(R.layout.shop_list_item, parent, false);
ViewHolder viewHolder = new ViewHolder(shoplist_itemView);
return viewHolder;
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
holder.location.setText(shopListItems.get(position).location.toString());
holder.normalPrice.setText(shopListItems.get(position).normalprice.toString());
holder.offerPrice.setText(shopListItems.get(position).offerprice.toString());
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(shopListItems.get(position).quantity + " " + shopListItems.get(position).name);
holder.productname.setText(stringBuilder);
if(!shopListItems.get(position).offerprice.toString().isEmpty()){
holder.normalPrice.setPaintFlags(holder.normalPrice.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
}
if(shopListItems.get(position).normalprice.isEmpty()){
holder.normalPrice.setVisibility(View.GONE);
}
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked == true){
holder.productname.setPaintFlags(holder.productname.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
holder.productname.setTextColor(Color.parseColor("#40000000"));
}else{
holder.productname.setPaintFlags(0 | Paint.ANTI_ALIAS_FLAG);
holder.productname.setTextColor(Color.BLACK);
}
}
});
}
@Override
public int getItemCount() {
return shopListItems.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder{
private CheckBox checkBox;
private TextView productname, quantity, location, normalPrice, offerPrice;
private ImageButton edit_icon, delete_icon;
public ViewHolder(View itemView) {
super(itemView);
productname = (TextView)itemView.findViewById(R.id.product_name);
location = (TextView)itemView.findViewById(R.id.product_location);
normalPrice = (TextView)itemView.findViewById(R.id.product_price);
offerPrice = (TextView)itemView.findViewById(R.id.product_offer_price);
edit_icon = (ImageButton)itemView.findViewById(R.id.editShopItem_Icon);
delete_icon = (ImageButton)itemView.findViewById(R.id.shopitem_delete_icon);
checkBox = (CheckBox) itemView.findViewById(R.id.bought_checkbox);
}
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
我的recyclerView适配器类:
public class DialogAdd extends DialogFragment {
private Button okButton;
private EditText name, quantity, location, normalPrice, offerPrice;
private List<ShopListItem> shopListItem;
private Context context;
DatabaseHelper dbHelper;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dbHelper = new DatabaseHelper(getContext());
shopListItem = new ArrayList<>();
context = getActivity();
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.add_productdialog,container, false);
getDialog().setCanceledOnTouchOutside(false);
getDialog().setTitle("Add to shoplist");
name = (EditText) rootView.findViewById(R.id.dialog_productname);
quantity = (EditText) rootView.findViewById(R.id.dialog_qantity);
location = (EditText) rootView.findViewById(R.id.dialog_location);
normalPrice = (EditText) rootView.findViewById(R.id.dialog_normalPrice);
offerPrice = (EditText) rootView.findViewById(R.id.dialog_offerPrice);
okButton = (Button) rootView.findViewById(R.id.dialog_okButton);
okButton.getBackground().setColorFilter(Color.parseColor("#2fbd4b"), PorterDuff.Mode.MULTIPLY);
okButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (name.getText().toString().isEmpty()) {
Toast.makeText(context, "You must add a name", Toast.LENGTH_LONG).show();
} else {
dbHelper.insertData(name.toString() ,quantity.toString(),location.toString(),normalPrice.toString(),offerPrice.toString());
getDialog().dismiss();
}
}
});
return rootView;
}
public class MainActivity extends AppCompatActivity{
private ImageButton addbutton;
private DialogAdd dialogAdd;
public static RecyclerView recyclerView;
private List<ShopListItem> shopListItems;
private SQLiteDatabase db;
private Cursor cursor;
private DatabaseHelper databaseHelper;
private ShoplistAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.shoppinglist_mainactivity);
databaseHelper = new DatabaseHelper(this);
addbutton = (ImageButton) findViewById(R.id.addbtn);
addbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dialogAdd = new DialogAdd();
dialogAdd.show(getSupportFragmentManager(), "addDialog");
}
});
//RecyclerView
recyclerView = (RecyclerView)findViewById(R.id.rv_shoppinglist);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(App.getAppContex());
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(linearLayoutManager);
initializeData();
adapter = new ShoplistAdapter(shopListItems);
recyclerView.setAdapter(adapter);
}
private void initializeData(){
shopListItems = new ArrayList<>();
Cursor resultset = databaseHelper.getAllData();
if (resultset.moveToFirst()){
while(!resultset.isAfterLast()){
shopListItems.add(new ShopListItem(resultset.getString(1), resultset.getString(2), resultset.getString(3), resultset.getString(4), resultset.getString(5)));
resultset.moveToNext();
}
}
resultset.close();
shopListItems.add(new ShopListItem("Potato", "2 KG", "MALL", "7 kr", ""));
}
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME ="dbshoplist.db";
public static final String TABLE_NAME ="product_table";
public static final String COL_ID = "ID";
public static final String COL_NAME ="NAME";
public static final String COL_QTY ="QUANTITY";
public static final String COL_LOCATION ="LOCATION";
public static final String COL_PRICE1 ="PRICE1";
public static final String COL_PRICE2 ="PRICE2";
/*
This constructor creates the database
*/
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
SQLiteDatabase db = this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,QUANTITY TEXT,LOCATION TEXT,PRICE1 TEXT,PRICE2 TEXT)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public boolean insertData(String name, String qty, String location, String price1, String price2){
SQLiteDatabase db = this.getWritableDatabase();
// content value is a row, and we fill it with the put();
ContentValues contentValues = new ContentValues();
contentValues.put(COL_NAME, name);
contentValues.put(COL_QTY, qty);
contentValues.put(COL_LOCATION, location);
contentValues.put(COL_PRICE1, price1);
contentValues.put(COL_PRICE2, price2);
long result = db.insert(TABLE_NAME, null,contentValues);
if(result == -1) {
return false;
}else{
return true;
}
}
public Cursor getAllData(){
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursorResults = db.rawQuery("SELECT * FROM " + TABLE_NAME, null);
return cursorResults;
}
public class ShoplistAdapter extends RecyclerView.Adapter<ShoplistAdapter.ViewHolder>{
List<ShopListItem> shopListItems;
public ShoplistAdapter(List<ShopListItem> shopListItems) {
this.shopListItems = shopListItems;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Context context = parent.getContext();
LayoutInflater inflater = LayoutInflater.from(context);
View shoplist_itemView = inflater.inflate(R.layout.shop_list_item, parent, false);
ViewHolder viewHolder = new ViewHolder(shoplist_itemView);
return viewHolder;
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
holder.location.setText(shopListItems.get(position).location.toString());
holder.normalPrice.setText(shopListItems.get(position).normalprice.toString());
holder.offerPrice.setText(shopListItems.get(position).offerprice.toString());
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(shopListItems.get(position).quantity + " " + shopListItems.get(position).name);
holder.productname.setText(stringBuilder);
if(!shopListItems.get(position).offerprice.toString().isEmpty()){
holder.normalPrice.setPaintFlags(holder.normalPrice.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
}
if(shopListItems.get(position).normalprice.isEmpty()){
holder.normalPrice.setVisibility(View.GONE);
}
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked == true){
holder.productname.setPaintFlags(holder.productname.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
holder.productname.setTextColor(Color.parseColor("#40000000"));
}else{
holder.productname.setPaintFlags(0 | Paint.ANTI_ALIAS_FLAG);
holder.productname.setTextColor(Color.BLACK);
}
}
});
}
@Override
public int getItemCount() {
return shopListItems.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder{
private CheckBox checkBox;
private TextView productname, quantity, location, normalPrice, offerPrice;
private ImageButton edit_icon, delete_icon;
public ViewHolder(View itemView) {
super(itemView);
productname = (TextView)itemView.findViewById(R.id.product_name);
location = (TextView)itemView.findViewById(R.id.product_location);
normalPrice = (TextView)itemView.findViewById(R.id.product_price);
offerPrice = (TextView)itemView.findViewById(R.id.product_offer_price);
edit_icon = (ImageButton)itemView.findViewById(R.id.editShopItem_Icon);
delete_icon = (ImageButton)itemView.findViewById(R.id.shopitem_delete_icon);
checkBox = (CheckBox) itemView.findViewById(R.id.bought_checkbox);
}
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
公共类ShoplistAdapter扩展了RecyclerView.Adapter{
列出购物清单;
公共ShoplistAdapter(列出shopListItems){
this.shopListItems=shopListItems;
}
@凌驾
public ViewHolder onCreateViewHolder(视图组父级,int-viewType){
Context=parent.getContext();
LayoutFlater充气机=LayoutFlater.from(上下文);
查看购物清单\项目视图=充气机。充气(R.layout.shop\列表\项目,父项,false);
ViewHolder ViewHolder=新的ViewHolder(shoplist\u itemView);
返回视图持有者;
}
@凌驾
公共无效onBindViewHolder(最终视图持有人,最终整型位置){
holder.location.setText(shopListItems.get(position.location.toString());
holder.normalPrice.setText(shopListItems.get(position.normalPrice.toString());
holder.offerPrice.setText(shopListItems.get(position.offerPrice.toString());
StringBuilder StringBuilder=新的StringBuilder();
stringBuilder.append(shopListItems.get(position).quantity+“”+shopListItems.get(position).name);
holder.productname.setText(stringBuilder);
if(!shopListItems.get(position).offerprice.toString().isEmpty()){
holder.normalPrice.setPaintFlags(holder.normalPrice.getPaintFlags()| Paint.STRIKE_-THRU_-TEXT_-FLAG);
}
if(shopListItems.get(position).normalprice.isEmpty()){
holder.normalPrice.setVisibility(View.GONE);
}
setOnCheckedChangeListener(newcompoundButton.OnCheckedChangeListener()){
@凌驾
检查更改后的公共无效(复合按钮视图,布尔值已检查){
如果(isChecked==true){
holder.productname.setPaintFlags(holder.productname.getPaintFlags()| Paint.STRIKE_THRU_TEXT_FLAG);
holder.productname.setTextColor(Color.parseColor(#40000000));
}否则{
holder.productname.setPaintFlags(0 | Paint.ANTI_别名_标志);
holder.productname.setTextColor(Color.BLACK);
}
}
});
}
@凌驾
public int getItemCount(){
return shopListItems.size();
}
公共静态类ViewHolder扩展了RecyclerView.ViewHolder{
私有复选框;
私有TextView产品名称、数量、位置、正常价格、报价;
私有图像按钮编辑图标,删除图标;
公共视图持有者(视图项视图){
超级(项目视图);
productname=(TextView)itemView.findViewById(R.id.product\u名称);
location=(TextView)itemView.findViewById(R.id.product\u位置);
normalPrice=(TextView)itemView.findViewById(R.id.product\u price);
offerPrice=(TextView)itemView.findViewById(R.id.product\u offer\u price);
edit_icon=(ImageButton)itemView.findViewById(R.id.editShopItem_icon);
delete_icon=(ImageButton)itemView.findViewById(R.id.shopitem_delete_icon);
checkBox=(checkBox)itemviewbyd(R.id.bunded\u checkBox);
}
}
@凌驾
附加ToRecyclerView(RecyclerView RecyclerView)上的公共无效{
super.onAttachedToRecyclerView(recyclerView);
}
发生这种情况是因为您正在调用ShopListItem对象字段的toString()
方法:shopListItems.get(position).location.toString()
相反,为ShopListItem类的字段创建getter方法,例如
public getLocation() {
return location;
}
只需调用这些函数即可获取数据。之所以发生这种情况,是因为您正在调用ShopListItem对象字段的
toString()
方法:shopListItems.get(position).location.toString()
相反,为ShopListItem类的字段创建getter方法,例如
public getLocation() {
return location;
}
然后调用这些来获取数据。你能分享适配器的代码吗?@howdothis是的,先生!你刚才做了,因为在onBindViewHolder下,你调用
toString()
来获取文本。默认的toString()
只返回该对象的表示形式,这不是您想要的。您可以为适配器共享您的代码吗?@howdoothis是的,先生!您这样做是因为在onBindViewHolder下,您正在调用toString()
以获取文本。默认值为toString()
只返回该对象的表示形式,这不是您想要的。谢谢!它成功了!!!我在recyclerView中还有一个小问题。也许我可以发布一个新问题(这样您就可以得到分数)你可以回答吗?这是关于让它立即显示添加的数据。现在我必须重新启动应用程序以显示新数据。你是否尝试调用notifyDataSetChaned()
在适配器上?是的!我刚刚就这个问题向她提出了一个新问题。看一看:哦,谢谢你!它成功了!!!我在recyclerView上还有一个小问题。也许我可以发布一个新问题(这样你就可以得到分数)你可以回答吗?这是关于让它立即显示添加的数据。现在我必须重新启动应用程序以显示新数据。你是否尝试在适配器上调用notifyDataSetChaned()
?是的!我刚刚为这个问题问了一个新问题。请看: