【发布时间】：2019-09-26 05:16:06
【问题描述】：
我正在将 JSON 解析为 ExpandableListView，在每个孩子上，用户可以选择他想要的每个孩子的数量 +/- 按钮。 +/- 按钮连接到 TextView，其中显示每个孩子的总金额，总费用将显示在行尾。
在父级的底部应该有一个TextView，其中包含在ExpListView的每个子级中计算的所有值的摘要（摘要） 底部的 OK 按钮应该将每个孩子的金额发送到服务器（金额连接到一个 ID）。
当我点击“确定”按钮时，我在读取每个孩子的数量时遇到问题 - 我如何搭建通往孩子价值观的桥梁？
我也遇到了读取每个孩子的成本以计算底部的总成本的问题。 Child 中的 onClickListener 应该以某种方式刷新底部的 TextView，但据我所知，这并不容易，对吧？
有人知道如何访问这些值吗？
这是我的 ListAdapter 的 ChildView 发生魔法的地方：
public class ExpandableListAdapterDrinks extends BaseExpandableListAdapter {
private Context context;
private List<String> listDataHeader,listDataHeaderPrice;
private HashMap<String,List<String>> listHashMap;
private List<Drink> drinksList;
class ViewHolder {
TextView childText,counterText, childUnitPrice, childFinalPrice;
Button btn_plus,btn_minus;
}
class DrinksListChildItem{
String name;
int quantity;
DrinksListChildItem(String name, int quantity){
this.name = name;
this.quantity = quantity;
}
}
class Pos{
int group;
int child;
Pos(int group, int child){
this.group = group;
this.child = child;
}
}
public ExpandableListAdapterDrinks(Context context, List<Drink> drinksList) {
this.context = context;
this.drinksList= drinksList;
}
@Override
public int getGroupCount() {
return drinksList.size();
}
@Override
public int getChildrenCount(int groupPosition) {
return drinksList.get(groupPosition).getContent().size();
}
@Override
public Object getGroup(int groupPosition) {
return drinksList.get(groupPosition);
}
@Override
public Object getChild(int groupPosition, int childPosition) {
return drinksList.get(groupPosition).getContent();
listHashMap.get(listDataHeader.get(groupPosition)).get(childPosition);
}
@Override
public long getGroupId(int groupPosition) {
return groupPosition;
}
@Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
@Override
public boolean hasStableIds() {
return false;
}
@Override
public View getGroupView(final int groupPosition, boolean isExpanded, View view, ViewGroup parent) {
String headerTitle = (String) drinksList.get(groupPosition).getTitle();
/** HEADER TEXT HERE */
if(view==null) {
LayoutInflater inflater = (LayoutInflater)this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.vip_package_listgroup,null);
}
final LinearLayout bgcolor = view.findViewById(R.id.lblListHeaderLayout);
TextView lblListHeader = (TextView)view.findViewById(R.id.lblListHeader);
TextView lblListHeaderPrice = (TextView)view.findViewById(R.id.lblListHeader_Price);
Button lblListHeaderButton = view.findViewById(R.id.lblListHeaderButton);
lblListHeaderPrice.setVisibility(View.GONE);
lblListHeaderButton.setVisibility(View.GONE);
if(!drinksList.get(groupPosition).getBg().get(0).isEmpty() || !drinksList.get(groupPosition).getBg().get(1).isEmpty() ) {
List<String> colorGradientTopBottom = drinksList.get(groupPosition).getBg();
int[] colors = {Color.parseColor(colorGradientTopBottom.get(0)),Color.parseColor(colorGradientTopBottom.get(1))};
GradientDrawable gd = new GradientDrawable(GradientDrawable.Orientation.TOP_BOTTOM, colors);
gd.setCornerRadius(0f);
bgcolor.setBackground(gd);
} else {
bgcolor.setBackgroundColor(ContextCompat.getColor(context, R.color.cardview_bg));
}
lblListHeader.setText(headerTitle);
return view;
}
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View view, ViewGroup parent) {
/** Drinks List */
final ViewHolder viewHolder;
final List<String> childDrink = drinksList.get(groupPosition).getContent();
final List<Integer> childPrice = drinksList.get(groupPosition).getPricelist();
//final String childText = childDrink.get(childPosition);
if(view == null) {
LayoutInflater inflater = (LayoutInflater)this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.vip_drinks_listitem,null);
final TextView txtListChild = view.findViewById(R.id.lblListItemDrinks);
final TextView txtListDrinksUnitPrice = view.findViewById(R.id.lblListItemDrinksUnitPrice);
final TextView txtDrinksAmount = view.findViewById(R.id.vip_drinks_amount);
final TextView txtListDrinkPriceFinal = view.findViewById(R.id.lblListItemDrinksFinalPrice);
Button btn_plus = view.findViewById(R.id.vip_drinks_btn_plus);
Button btn_minus = view.findViewById(R.id.vip_drinks_btn_minus);
viewHolder = new ViewHolder();
viewHolder.childText = txtListChild;
viewHolder.childUnitPrice = txtListDrinksUnitPrice;
viewHolder.counterText = txtDrinksAmount;
viewHolder.childFinalPrice = txtListDrinkPriceFinal;
viewHolder.btn_plus = btn_plus;
viewHolder.btn_minus = btn_minus;
viewHolder.childText.setText(childDrink.get(childPosition));
viewHolder.counterText.setText("0");
viewHolder.childFinalPrice.setText("0");
final float headerPrice = childPrice.get(childPosition);
final int headerPriceInt = (int) headerPrice;
viewHolder.childUnitPrice.setText(String.format("%.02f",headerPrice).replace(".",",") +"€");
DrinksListChildItem child = childDrink.get(childPosition);
viewHolder.btn_plus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int t = Integer.parseInt(viewHolder.counterText.getText().toString());
ChildItem selectedItem = viewHolder.counterText.getText().toString();
selectedItem.quantity = selectedItem.quantity+1;
notifyDataSetChanged();
viewHolder.counterText.setText(String.valueOf(t + 1));
viewHolder.childFinalPrice.setText(String.valueOf((t+1)* headerPriceInt) + "€");
}
});
viewHolder.btn_minus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Pos pos = (Pos) v.getTag();
int t = Integer.parseInt(viewHolder.counterText.getText().toString());
DrinksListChildItem selectedItem = (DrinksListChildItem) getChild(pos.group,pos.child);
selectedItem.quantity = selectedItem.quantity-1;
notifyDataSetChanged();
viewHolder.counterText.setText(String.valueOf(t - 1));
viewHolder.counterText.setText(String.valueOf((t-1)* headerPriceInt) + "€");
}
});
} else {
viewHolder = (ViewHolder) view.getTag();
}
return view;
我在将您的代码粘贴到我的代码时遇到了很多问题（使用 TextView 扩展问题）：我不明白如何连接 ChildItem child = childDrink.get(childPosition);到我的drinksList 以使setOnCLickListener 增加selectedItem.quantity。该代码以某种方式起作用，但它弄乱了我孩子的顺序，它还选择了其他孩子的数量
饮料（Pojo）
public class Drink {
@SerializedName("title")
@Expose
private String title;
@SerializedName("bg")
@Expose
private List<String> bg = null;
@SerializedName("content")
@Expose
private List<String> content = null;
@SerializedName("pricelist")
@Expose
private List<Integer> pricelist = null;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public List<String> getBg() {
return bg;
}
public void setBg(List<String> bg) {
this.bg = bg;
}
public List<String> getContent() {
return content;
}
public void setContent(List<String> content) {
this.content = content;
}
public List<Integer> getPricelist() {
return pricelist;
}
public void setPricelist(List<Integer> pricelist) {
this.pricelist = pricelist;
}
}
VipDrinks(Pojo): 公共类 VipDrinks {
@SerializedName("drinks")
@Expose
private List<Drink> drinks = null;
public List<Drink> getDrinks() {
return drinks;
}
public void setDrinks(List<Drink> drinks) {
this.drinks = drinks;
}
}
JSON 的结构如下：
{
"drinks":[ {
"title":,
"bg":[],
"content":[],
"pricelist":[],
},
{...}
]
}
这是带有解析请求的活动：
public class drinks_selection extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_drinks_selection);
final ExpandableListView listView = findViewById(R.id.vip_drinks_listview);
/** PARSING JSON FROM SERVER */
final JsonObjectRequest galleryUrls = new JsonObjectRequest(Request.Method.GET, PARSE_URL, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
JSONArray packageArray = response.getJSONArray("drinks");
Log.e("response", String.valueOf(response));
GsonBuilder gsonBuilder = new GsonBuilder();
Gson gson = gsonBuilder.create();
List<Drink> vipDrinks = Arrays.asList(gson.fromJson(String.valueOf(packageArray),Drink[].class));
List<Drink> arrayList = new ArrayList<>(vipDrinks);
ExpandableListAdapterDrinks listAdapter = new ExpandableListAdapterDrinks(getApplicationContext(),arrayList);
listView.setAdapter( listAdapter);
listView.expandGroup(0);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e("ERROR", String.valueOf(error));
}
});
RequestQueue rQ = Volley.newRequestQueue(this);
rQ.add(galleryUrls);
}
}
VIP包列表Group.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:id="@+id/lblListHeaderLayout"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="@dimen/default_padding"
android:background="@drawable/bg_vip_booking"
android:orientation="horizontal"
>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:paddingStart="?android:attr/expandableListPreferredItemPaddingLeft"
android:paddingEnd="@dimen/feed_item_padding_left_right"
android:layout_weight="0.9"
>
<TextView
android:id="@+id/lblListHeader"
android:textSize="@dimen/text_title_list_header"
android:textColor="@color/Textwhite"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="@font/mont_bold"
/>
<TextView
android:id="@+id/lblListHeader_Price"
android:textSize="@dimen/text_title_list_header"
android:textColor="@color/Textwhite"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:fontFamily="@font/mont_bold"
/>
</RelativeLayout>
<Button
android:id="@+id/lblListHeaderButton"
android:layout_width="60dp"
android:layout_height="30dp"
android:background="@drawable/bg_btn_ripple_dark"
android:text="@string/btn_ok"
android:textColor="@color/Textwhite"
android:fontFamily="@font/mont_bold"
android:focusable="false"
/>
</LinearLayout>
VIP 酒水 ListItem.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="60dip"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_centerInParent="true"
>
<TextView
android:id="@+id/lblListItemDrinks"
android:paddingTop="@dimen/padding_small"
android:paddingBottom="@dimen/padding_small"
android:textSize="@dimen/text_normal"
android:paddingLeft="@dimen/default_padding"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:fontFamily="@font/mont_medium"
android:textColor="@color/Textwhite"
app:layout_constraintStart_toStartOf="parent"
/>
<RelativeLayout
android:id="@+id/vip_drinks_layout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toEndOf="@id/lblListItemDrinks"
android:paddingStart="@dimen/default_padding"
android:layout_centerInParent="true"
android:paddingEnd="@dimen/default_padding"
app:layout_constraintEnd_toEndOf="parent"
>
<TextView
android:id="@+id/lblListItemDrinksUnitPrice"
android:textSize="@dimen/text_normal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="@font/mont_light"
android:textColor="@color/Textwhite"
android:paddingEnd="@dimen/padding_small"
/>
<Button
android:id="@+id/vip_drinks_btn_minus"
android:layout_toEndOf="@id/lblListItemDrinksUnitPrice"
android:layout_width="30dp"
android:layout_height="20dp"
android:text="-"
android:background="@drawable/bg_btn_ripple_dark"
android:textColor="@color/white"
android:textSize="14sp"
android:layout_marginEnd="@dimen/padding_small"
/>
<TextView
android:id="@+id/vip_drinks_amount"
android:layout_toEndOf="@+id/vip_drinks_btn_minus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@color/white"
android:fontFamily="@font/mont_light"
android:textSize="@dimen/text_normal"
android:layout_marginEnd="@dimen/padding_small"
/>
<Button
android:id="@+id/vip_drinks_btn_plus"
android:layout_toEndOf="@+id/vip_drinks_amount"
android:layout_width="30dp"
android:layout_height="20dp"
android:text="+"
android:background="@drawable/bg_btn_ripple_dark"
android:textColor="@color/white"
android:textSize="14sp"
android:layout_marginEnd="@dimen/padding_small"
/>
<TextView
android:id="@+id/lblListItemDrinksFinalPrice"
android:layout_toEndOf="@id/vip_drinks_btn_plus"
android:textSize="@dimen/text_normal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="@font/mont_light"
android:textColor="@color/Textwhite"
/>
</RelativeLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
【问题讨论】：
-
由于 View 会被重复使用/回收，所以将数据保存在 TextView 中是错误的。它们将在折叠/展开或滚动后网格化。尝试修改您的饮料列表以保留数据。我在这篇文章中的示例可能会有所帮助：stackoverflow.com/questions/50092400/…
-
对于 OK 按钮，尝试在适配器内部创建一个公共方法并获取那些选择的数量不为 0 的子项。看看 getOrderList() b> 我对这篇文章的回答的适配器中的方法：stackoverflow.com/questions/50288713/…
-
要访问 ExpandableListView 之外的 TextView，请尝试：1。在适配器中，添加一个TextView全局变量； 2.在适配器的构造函数中，为TextView添加一个参数； 3. 在构造函数中，使 TextView 全局变量 = TextView 参数。希望有帮助！
-
查看我的代码更新，由于您在代码中使用的 HashMap 而我的代码中缺少，因此无法将您的 selectedItem.quantity 连接到我的 DrinksList
-
请同时发布 Drink 课程。
标签： java android xml expandablelistview expandablelistadapter