导入资源中定义的对象数组

在某些情况下，需要在应用程序的资源中创建和定义自定义对象。这些对象可以由 Java 简单类型组成，例如 Integer，Float，String。

以下是如何导入应用程序资源中定义的对象的示例。对象 Category 包含 3 个属性：

• ID
• 颜色
• 名称

这个 POJO 在 categories.xml 文件中具有相同的功能，其中每个数组都具有为每个类别定义的相同属性。

1. 为你的对象创建模型：

public class Category {
    private Type id;
    private @ColorRes int color;
    private @StringRes String name;

    public Category getId() {
        return id;
    }

    public void setId(Category id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getColor() {
        return color;
    }

    public void setColor(int color) {
        this.color = color;
    }

    public enum Type{
        REGISTRATION,
        TO_ACCEPT,
        TO_COMPLETE,
        TO_VERIFY,
        CLOSED
    }
}

2. 在 res/values 文件夹中创建文件：

categories.xml

3. 撰写由资源组成的每个模型：

<array name="no_action">
    <item>0</item>
    <item>@android:color/transparent</item>
    <item>@string/statusRegistration</item>
</array>
<array name="to_accept">
    <item>1</item>
    <item>@color/light_gray</item>
    <item>@string/acceptance</item>
</array>
<array name="opened">
    <item>2</item>
    <item>@color/material_green_500</item>
    <item>@string/open</item>
</array>
<array name="to_verify">
    <item>3</item>
    <item>@color/material_gray_800</item>
    <item>@string/verification</item>
</array>
<array name="to_close">
    <item>4</item>
    <item>@android:color/black</item>
    <item>@string/closed</item>
</array>

4. 在资源文件中定义一个数组：

   <array name="categories">
       <item>@array/no_action</item>
       <item>@array/to_accept</item>
       <item>@array/opened</item>
       <item>@array/to_verify</item>
       <item>@array/to_close</item>
   </array>
   

5. 创建一个导入它们的函数：

   @NonNull
   public List<Category> getCategories(@NonNull Context context) {
   final int DEFAULT_VALUE = 0;
   final int ID_INDEX = 0;
   final int COLOR_INDEX = 1;
   final int LABEL_INDEX = 2;
   
   if (context == null) {
       return Collections.emptyList();
   }
   // Get the array of objects from the `tasks_categories` array
   TypedArray statuses = context.getResources().obtainTypedArray(R.array.categories);
   if (statuses == null) {
       return Collections.emptyList();
   }
   List<Category> categoryList = new ArrayList<>();
   for (int i = 0; i < statuses.length(); i++) {
       int statusId = statuses.getResourceId(i, DEFAULT_VALUE);
       // Get the properties of one object
       TypedArray rawStatus = context.getResources().obtainTypedArray(statusId);
   
       Category category = new Category();
   
       int id = rawStatus.getInteger(ID_INDEX, DEFAULT_VALUE);
       Category.Type categoryId;
       //The ID's should maintain the order with `Category.Type`
       switch (id) { 
           case 0:
               categoryId = Category.Type.REGISTRATION;
               break;
           case 1:
               categoryId = Category.Type.TO_ACCEPT;
               break;
           case 2:
               categoryId = Category.Type.TO_COMPLETE;
               break;
           case 3:
               categoryId = Category.Type.TO_VERIFY;
               break;
           case 4:
               categoryId  = Category.Type.CLOSED;
               break;
           default:
               categoryId = Category.Type.REGISTRATION;
               break;
       }
       category.setId(categoryId);
   
       category.setColor(rawStatus.getResourceId(COLOR_INDEX, DEFAULT_VALUE));
   
       int labelId = rawStatus.getResourceId(LABEL_INDEX, DEFAULT_VALUE);
       category.setName(getString(context.getResources(), labelId));
   
       categoryList.add(taskCategory);
   }
   return taskCategoryList;
   }