每个列表项的不同意图 Android

Question

我正在尝试为 Coins.java 中的每个列表项赋予意图。当我添加 Intent 时，它会将我带到同一页面。我在 StackOverflow 上搜索可能的答案。许多答案说使用 switch 语句来给出不同的意图。但是，在我的应用程序中，列表中的项目数不是一个常数。它可能是 10 或 5 甚至 100。我在 StackOverflow 中搜索了答案，但我可以找到任何适用于我的应用程序的答案。谁能告诉我该怎么做？提前致谢。

1. Coins.java

   package com.example.android.cotescol;
   import android.content.Intent;
   import android.os.Bundle;
   import android.view.LayoutInflater;
   import android.view.View;
   import android.view.ViewGroup;
   import android.widget.AdapterView;
   import android.widget.ListView;
   import java.util.ArrayList;
   
   public class Coins extends android.support.v4.app.Fragment{    
       @Override
       public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
           View rootView = inflater.inflate(R.layout.currency_list, container, false);
           final ArrayList<CoinObject> coins = new ArrayList<CoinObject>();
           coins.add(new CoinObject(1, "India", 1947));
           coins.add(new CoinObject(1, "India", 1947));
   
           CoinAdapter itemsAdapter = new CoinAdapter(getActivity(), coins);
           ListView listView = (ListView) rootView.findViewById(R.id.list);
           listView.setAdapter(itemsAdapter);
   
           listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
               @Override
               public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                   CoinObject coinObject = coins.get(position);
                   Intent intent = new Intent(Coins.this.getActivity(), DetailsActivity.class);
                   startActivity(intent);
               }
           });
   
           return rootView;
       }
   }
   

2. CoinObject.java

   package com.example.android.cotescol;
   
   import java.util.HashMap;
   import java.util.Locale;
   import java.util.Map;
   
   public class CoinObject {
   
       private final static int NO_IMAGE_AVAILABLE = R.drawable.nia;
       private final static String NOT_AVAILABLE = "Material Not Specified";
       private final static double NOT_KNOWN = 0.00;
   
       private int denomination;
       private String country;
       private String countryCode;
       private int year;
       private int obverseImageResourceId = NO_IMAGE_AVAILABLE;
       private int reverseImageResourceId = NO_IMAGE_AVAILABLE;
       private String material = NOT_AVAILABLE;
       private double diameter = NOT_KNOWN;
       private double weight = NOT_KNOWN;
       private double thickness = NOT_KNOWN;
       private double value = NOT_KNOWN;
   
       public CoinObject(int denomination, String country, int year, int obverseImageResourceId, int reverseImageResourceId , double diameter, double thickness, String material, double weight, double value) {
           this.denomination = denomination;
           this.country = country;
           this.year = year;
           this.obverseImageResourceId = obverseImageResourceId;
           this.reverseImageResourceId = reverseImageResourceId;
           this.diameter = diameter;
           this.thickness = thickness;
           this.material = material;
           this.weight = weight;
           this.value = value;
           this.countryCode = getCountryCode(country);
       }
   
       public CoinObject(int denomination, String country, int year, double diameter, double thickness, String material, double weight, double value) {
           this.denomination = denomination;
           this.country = country;
           this.year = year;
           this.diameter = diameter;
           this.thickness = thickness;
           this.material = material;
           this.weight = weight;
           this.value = value;
           this.countryCode = getCountryCode(country);
       }
   
       public CoinObject(int denomination, String country, int year) {
           this.denomination = denomination;
           this.country = country;
           this.year = year;
           this.countryCode = getCountryCode(country);
       }
   
       public String getCountryCode(String countryName) {
           // Get all country codes in a string array.
           String[] isoCountryCodes = Locale.getISOCountries();
           Map<String, String> countryMap = new HashMap<>();
           // Iterate through all country codes:
           for (String code : isoCountryCodes) {
               // Create a locale using each country code
               Locale locale = new Locale("", code);
               // Get country name for each code.
               String name = locale.getDisplayCountry();
               // Map all country names and codes in key - value pairs.
               countryMap.put(name, code);
           }
           // Get the country code for the given country name using the map.
           // Here you will need some validation or better yet
           // a list of countries to give to user to choose from.
           String countryCode = countryMap.get(countryName); // "NL" for Netherlands.  
   
           return countryCode;
       }
   
       public int getDenomination() { return denomination; }
       public int getYear() { return year; }
       public int getObverseImageResourceId() { return obverseImageResourceId; }
       public int getReverseImageResourceId() { return reverseImageResourceId; }
       public double getDiameter() { return diameter; }
       public double getWeight() { return weight; }
       public double getThickness() { return thickness; }
       public double getValue() { return value; }
       public String getCountry() { return country; }
       public String getCountryCode() { return countryCode; }
       public String getMaterial() { return material; }
   }
   

Answer 1

您应该将您的 Coin 对象设为 Parcelable，然后您可以将该对象作为额外的 Intent 传递，

intent.putExtra("coin", coinObject);

然后你在你的Activity中提取硬币对象，

Coin coin = intent.getParcelableExtra("coin");