Android 仅显示一项的列表视图
我正在制作一个AndroidAndroid 仅显示一项的列表视图,android,listview,firebase,firebase-realtime-database,Android,Listview,Firebase,Firebase Realtime Database,我正在制作一个AndroidListView以显示Firebase数据库中的对象,但我正在添加项目,但只有一个项目显示在ListView中。我正在使用ArrayAdapter,所有代码如下。仅显示第一项,而不是提供的所有数据 示例JSON文件如下: { "items" : { "item0" : { "description" : "its an apple", "name" : "apples", "price" : 10, "pro
ListView
以显示Firebase数据库中的对象,但我正在添加项目,但只有一个项目显示在ListView
中。我正在使用ArrayAdapter
,所有代码如下。仅显示第一项,而不是提供的所有数据
示例JSON文件如下:
{
"items" : {
"item0" : {
"description" : "its an apple",
"name" : "apples",
"price" : 10,
"productID" : 0,
"quantity" : 5,
"type" : "fruit"
},
"item1" : {
"description" : "its an orange",
"name" : "oranges",
"price" : 10,
"productID" : 1,
"quantity" : 15,
"type" : "fruit"
},
"item2" : {
"description" : "bagle",
"name" : "bagles",
"price" : 9,
"productID" : 2,
"quantity" : 7,
"type" : "food"
}
},
"users" : {
"dummy" : "keep this entry. without this, the other entries won't appear on the database"
}
}
活动主应用程序页面.xml
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.ub.akshay.nitkart.MainAppPage">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="@dimen/appbar_padding_top"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="@style/AppTheme.PopupOverlay">
</android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>
<ListView
android:id="@+id/shoppingList"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="8dp"
android:paddingBottom="120dp"
android:clipToPadding="false"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
android:scrollbarStyle="outsideOverlay" />
<ProgressBar
android:id="@+id/mainPageProgressBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/cartMainPage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:layout_margin="@dimen/fab_margin"
app:backgroundTint="@android:color/background_light"
app:srcCompat="@drawable/ic_shopping_cart_black_24dp" />
</android.support.design.widget.CoordinatorLayout>`
`
MainActivity.java
package com.ub.tom.smith;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.ProgressBar;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import java.util.ArrayList;
public class MainAppPage extends AppCompatActivity {
public final String TAG = MainAppPage.class.getSimpleName();
ListView shoppingItemView;
ShoppingListAdapter adapter;
ProgressBar progressBar;
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("items");
private Boolean exit = false;
private ArrayList<ShoppingItem> shoppingItems;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_app_page);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("NITKart");
setSupportActionBar(toolbar);
FloatingActionButton shoppingCart = (FloatingActionButton)
findViewById(R.id.cartMainPage);
shoppingCart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
startActivity(new Intent(getApplicationContext(),
ShoppingCartWindow.class));
}
});
progressBar = (ProgressBar)
findViewById(R.id.mainPageProgressBar);
shoppingItemView = (ListView) findViewById(R.id.shoppingList);
myRef.addValueEventListener(new ValueEventListener() {
// This listener is only for database with reference of key
"items"
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// This method is called once with the initial value and
again
// whenever data at this location is updated.
// Now the Shopping List gets updated whenever the data
shoppingItems = getAllItems(dataSnapshot);
adapter = new ShoppingListAdapter(getApplicationContext(),
shoppingItems);
progressBar.setVisibility(View.GONE);
shoppingItemView.setAdapter(adapter);
}
@Override
public void onCancelled(DatabaseError error) {
// Failed to read value
Log.w(TAG, "Failed to read value.", error.toException());
}
});
shoppingItemView.setOnItemClickListener(new
AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view,
int i, long l) {
Intent productIntent = new Intent(MainAppPage.this,
IndividualProduct.class);
productIntent.putExtra("product", shoppingItems.get(i));
startActivity(productIntent);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is
getMenuInflater().inflate(R.menu.menu_main_app_page, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.logoutItem) {
FirebaseAuth.getInstance().signOut();
startActivity(new Intent(getApplicationContext(),
OpenScreen.class));
finish();
}
return super.onOptionsItemSelected(item);
}
// For exiting the application
@Override
public void onBackPressed() {
if (exit) {
finish();
} else {
Snackbar.make(findViewById(R.id.main_content), "Press back
again to exit", Snackbar.LENGTH_SHORT).show();
exit = true;
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
exit = false;
}
}, 2000);
}
}
public static ArrayList<ShoppingItem> getAllItems(DataSnapshot
dataSnapshot){
ArrayList<ShoppingItem> items = new ArrayList<ShoppingItem>();
for (DataSnapshot item : dataSnapshot.getChildren()) {
items.add(new ShoppingItem(
Integer.valueOf(item.child("productID").getValue().toString()),
item.child("name").getValue().toString(),
item.child("type").getValue().toString(),
item.child("description").getValue().toString(),
Integer.valueOf(item.child("price").getValue().toString()),
Integer.valueOf(item.child("quantity").getValue().toString())
));
}
return items;
}
}
package com.ub.tom.smith;
导入android.content.Intent;
导入android.os.Bundle;
导入android.os.Handler;
导入android.support.design.widget.FloatingActionButton;
导入android.support.design.widget.Snackbar;
导入android.support.v7.app.AppActivity;
导入android.support.v7.widget.Toolbar;
导入android.util.Log;
导入android.view.Menu;
导入android.view.MenuItem;
导入android.view.view;
导入android.widget.AdapterView;
导入android.widget.ListView;
导入android.widget.ProgressBar;
导入com.google.firebase.auth.FirebaseAuth;
导入com.google.firebase.database.DataSnapshot;
导入com.google.firebase.database.DatabaseError;
导入com.google.firebase.database.DatabaseReference;
导入com.google.firebase.database.FirebaseDatabase;
导入com.google.firebase.database.ValueEventListener;
导入java.util.ArrayList;
公共类MainAppPage扩展了AppCompative活动{
public final String TAG=MainAppPage.class.getSimpleName();
ListView shoppingItemView;
购物列表适配器;
ProgressBar ProgressBar;
FirebaseDatabase=FirebaseDatabase.getInstance();
DatabaseReference myRef=database.getReference(“项”);
私有布尔退出=false;
私人ArrayList购物项目;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u main\u app\u页面);
Toolbar Toolbar=(Toolbar)findViewById(R.id.Toolbar);
工具栏。设置标题(“NITKart”);
设置支持操作栏(工具栏);
FloatingActionButton购物车=(FloatingActionButton)
findViewById(R.id.cartMainPage);
shoppingCart.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图){
startActivity(新意图)(getApplicationContext(),
ShoppingCartWindow.class);
}
});
progressBar=(progressBar)
findViewById(R.id.mainPageProgressBar);
shoppingItemView=(ListView)findViewById(R.id.shoppingList);
myRef.addValueEventListener(新的ValueEventListener(){
//此侦听器仅用于引用键的数据库
“项目”
@凌驾
公共void onDataChange(DataSnapshot DataSnapshot){
//使用初始值和
再一次
//每当更新此位置的数据时。
//现在,只要数据更新,购物清单就会更新
shoppingItems=getAllItems(dataSnapshot);
adapter=新的ShoppingListAdapter(getApplicationContext(),
购物物品),;
progressBar.setVisibility(View.GONE);
shoppingItemView.setAdapter(适配器);
}
@凌驾
已取消的公共无效(DatabaseError错误){
//无法读取值
Log.w(标记“读取值失败”,error.toException());
}
});
shoppingItemView.setOnItemClickListener(新建)
AdapterView.OnItemClickListener(){
@凌驾
公共无效onItemClick(AdapterView AdapterView,视图,
内部i,长l){
Intent productIntent=新Intent(MainAppPage.this,
个人产品(类别);
productIntent.putExtra(“产品”,shoppingItems.get(i));
startActivity(productIntent);
}
});
}
@凌驾
公共布尔onCreateOptions菜单(菜单){
//对菜单进行充气;这会将项目添加到操作栏(如果有)
getMenuInflater().充气(R.menu.menu\u main\u app\u页面,菜单);
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();
//noinspection SimplifiableIf语句
if(id==R.id.logoutItem){
FirebaseAuth.getInstance().signOut();
startActivity(新意图)(getApplicationContext(),
OpenScreen.class);
完成();
}
返回super.onOptionsItemSelected(项目);
}
//用于退出应用程序
@凌驾
public void onBackPressed(){
如果(退出){
完成();
}否则{
Snackbar.make(findviewbyd(R.id.main_内容),“按后退
再次退出”,Snackbar.LENGTH_SHORT.show();
退出=真;
new Handler().postDelayed(new Runnable()){
@凌驾
公开募捐{
退出=假;
}
}, 2000);
}
}
公共静态数组列表getAllItems(DataSnapshot
数据快照){
ArrayList items=新建ArrayList();
对于(DataSnapshot项:DataSnapshot.getChildren()){
项目。添加(新购物项目)(
Integer.valueOf(item.child(“productID”).getValue().toString()),
item.child(“name”).getValue().toString(),
item.child(“type”).getValue().toString(),
item.child(“description”).getValue().toString(),