Android：如何将微调器绑定到自定义对象列表？

Question

在用户界面中必须有一个微调器，其中包含一些名称（名称是可见的），并且每个名称都有自己的 ID（ID 不等于显示顺序）。当用户从列表中选择名称时，必须更改变量 currentID。

该应用程序包含 ArrayList

，其中 User 是一个具有 ID 和名称的对象：

public class User{
        public int ID;
        public String name;
    }

我不知道的是如何创建一个显示用户姓名列表的微调器并将微调器项目绑定到 ID，以便在选择/更改微调器项目时变量 currentID 设置为适当的值。

如果有人可以展示所描述问题的解决方案或提供任何有助于解决问题的链接，我将不胜感激。

谢谢！

Answer 1

对于简单的解决方案，您可以覆盖对象中的“toString”

public class User{
    public int ID;
    public String name;

    @Override
    public String toString() {
        return name;
    }
}

，然后您可以使用：

ArrayAdapter<User> dataAdapter = new ArrayAdapter<User>(mContext, android.R.layout.simple_spinner_item, listOfUsers);

这样您的微调器将仅显示用户名。

Answer 2

您可以查看此答案。您也可以使用自定义适配器，但下面的解决方案适用于简单的情况。

这里是一个转发：

因此，如果您来到这里是因为您想在 Spinner 中同时拥有标签和值 - 这就是我的做法：

1. 只需以通常的方式创建您的 Spinner
2. 定义 2 个相同大小的数组您的 array.xml 文件 - 一个标签数组，一个值数组
3. 使用 android:entries="@array/labels"Spinner >

4. 当您需要一个值时，请执行以下操作（不，您不必链接它）：

    String selectedVal = getResources().getStringArray(R.array.values)[spinner.getSelectedItemPosition()];
   

Answer 3

到目前为止，我发现的最简单的方法：

@Override
public String toString() {
    return this.label;           
}

现在您可以将任何对象粘贴到微调器中，它将显示指定的标签。

Answer 4

只需对 Joaquin Alberto 的答案做一点小小的调整就可以解决样式问题。只需替换自定义适配器中的 getDropDownView 函数，如下所示，

@Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        View v = super.getDropDownView(position, convertView, parent);
        TextView tv = ((TextView) v);
        tv.setText(values[position].getName());
        tv.setTextColor(Color.BLACK);
        return v;
    }

Answer 5

受到华金·阿尔贝托 (Joaquin Alberto) 的启发，这对我有用：

public class SpinAdapter extends ArrayAdapter<User>{


    public SpinAdapter(Context context, int textViewResourceId,
            User[] values) {
        super(context, textViewResourceId, values);
    }



    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        TextView label = (TextView) super.getView(position, convertView, parent);
        label.setTextColor(Color.BLACK);
        label.setText(this.getItem(position).getName());
        return label;
    }

    @Override
    public View getDropDownView(int position, View convertView,ViewGroup parent) {
        TextView label = (TextView) super.getView(position, convertView, parent);
        label.setTextColor(Color.BLACK);
        label.setText(this.getItem(position).getName());
        return label;
    }
}

Answer 6

对我来说效果很好，围绕 getResource() 所需的代码如下：

spinner = (Spinner) findViewById(R.id.spinner);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> spinner, View v,
                int arg2, long arg3) {
            String selectedVal = getResources().getStringArray(R.array.compass_rate_values)[spinner.getSelectedItemPosition()];
            //Do something with the value
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub
        }

    });

只需确保（自己）两个数组中的值正确对齐！

Answer 7

基于 Joaquin Alberto （感谢）示例，但它适用于任何类型（您应该在类型中实现 toString() ，这样您就可以格式化输出。

import java.util.List;

import android.content.Context;
import android.graphics.Color;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class SpinAdapter<T> extends ArrayAdapter<T> {
private Context context;
private List<T> values;

public SpinAdapter(Context context, int textViewResourceId, List<T> values) {
    super(context, textViewResourceId, values);
    this.context = context;
    this.values = values;
}

public int getCount() {
    return values.size();
}

public T getItem(int position) {
    return values.get(position);
}

public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    TextView label = new TextView(context);
    label.setTextColor(Color.BLACK);
    label.setText(values.toArray(new Object[values.size()])[position]
            .toString());
    return label;
}

@Override
public View getDropDownView(int position, View convertView, ViewGroup parent) {
    TextView label = new TextView(context);
    label.setTextColor(Color.BLACK);
    label.setText(values.toArray(new Object[values.size()])[position]
            .toString());

    return label;
}
}

另外我认为您可以用数组替换 List，这样您就不需要执行 toArray在列表中，但我有一个列表......:)

Answer 8

kotlin：

data class User(
    var id: Long,
    var name : String? ){

    override fun toString(): String {
        return name
    }
}

实现

 mBinding.ddUser.setOnItemClickListener { parent, view, position, id ->
            val user = adapter.getItem(position)
            Log.i("idUser","${user?.idtoString()} - ${user?.name}")
        }

Answer 9

为了理解这一技巧，我们必须了解适配器的一般工作原理，特别是 ArrayAdapter 的工作原理。

适配器：是能够将数据结构绑定到小部件的对象，然后这些小部件在列表或微调器中显示该数据。

因此，适配器回答的两个问题是：

1. 哪个小部件或复合视图需要与某个索引的数据结构（您的类的对象）关联？
2. 如何从数据结构（您的类的对象）中提取数据以及如何根据此数据设置小部件或复合视图的字段，即 EditText ？

ArrayAdapter 的答案是：

• 任何索引的每个小部件（即 row.xml 或 android.R.layout.simple_spinner_item）都是相同的，并且从 ID 为赋予 ArrayAdapter 的构造函数。
• 每个小部件都应该是 TextView 的一个实例（或
  后裔）。小部件的 .setText() 方法将与
  支持数据结构中项目的字符串格式。这
  字符串格式将通过在项目上调用 .toString() 来获取。

---

CustomListViewDemo.java

public class CustomListViewDemo extends ListActivity {
  private EfficientAdapter adap;

  private static String[] data = new String[] { "0", "1", "2", "3", "4" };

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);
    adap = new EfficientAdapter(this);
    setListAdapter(adap);
  }

  @Override
  protected void onListItemClick(ListView l, View v, int position, long id) {
    // TODO Auto-generated method stub
    super.onListItemClick(l, v, position, id);
    Toast.makeText(this, "Click-" + String.valueOf(position), Toast.LENGTH_SHORT).show();
  }

  public static class EfficientAdapter extends BaseAdapter implements Filterable {
    private LayoutInflater mInflater;
    private Bitmap mIcon1;
    private Context context;
    int firstpos=0;

    public EfficientAdapter(Context context) {
      // Cache the LayoutInflate to avoid asking for a new one each time.
      mInflater = LayoutInflater.from(context);
      this.context = context;
    }

    public View getView(final int position, View convertView, ViewGroup parent) {

      ViewHolder holder;

      if (convertView == null) {
        convertView = mInflater.inflate(R.layout.adaptor_content, null);

        holder = new ViewHolder();
        holder.sp = (Spinner) convertView.findViewById(R.id.spinner1);

        holder.ArrayAdapter_sp = new ArrayAdapter(parent.getContext(),android.R.layout.simple_spinner_item,data);
        holder.ArrayAdapter_sp.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        holder.sp.setAdapter( holder.ArrayAdapter_sp);
        holder.sp.setOnItemSelectedListener(new OnItemSelectedListener()
        {
            private int pos = position;
            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int p, long arg3) 
            {
                // TODO Auto-generated method stub
                 Toast.makeText(context, "select spinner " + String.valueOf(pos)+" with value ID "+p, Toast.LENGTH_SHORT).show();    

            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0)
            {
                // TODO Auto-generated method stub

            }
        });




        convertView.setTag(holder);
      } else {

        holder = (ViewHolder) convertView.getTag();
      }


      return convertView;
    }

    static class ViewHolder 
    {

        Spinner sp;
        ArrayAdapter ArrayAdapter_sp;

    }

    @Override
    public Filter getFilter() {
      // TODO Auto-generated method stub
      return null;
    }

    @Override
    public long getItemId(int position) {
      // TODO Auto-generated method stub
      return 0;
    }

    @Override
    public int getCount() {
      // TODO Auto-generated method stub
      return data.length;
    }

    @Override
    public Object getItem(int position) {
      // TODO Auto-generated method stub
      return data[position];
    }

  }

}

---

adaptor_content.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/lineItem"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical" >

    <Spinner
        android:id="@+id/spinner1"
        android:layout_width="314dp"
        android:layout_height="wrap_content" />

</LinearLayout>

---

ma​​in.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="fill_parent" android:layout_width="fill_parent"
    >

    <ListView
        android:id="@+id/android:list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_marginBottom="60dip"
        android:layout_marginTop="10dip"
        android:cacheColorHint="#00000000"
        android:drawSelectorOnTop="false" />

</RelativeLayout>

它工作正常，我希望它有用。

Answer 10

这是 Kotlin 中的完整过程：

微调器适配器类：

class CustomSpinnerAdapter(
    context: Context,
    textViewResourceId: Int,
    val list: List<User>
) : ArrayAdapter<User>(
    context,
    textViewResourceId,
    list
) {
    override fun getCount() = list.size

    override fun getItem(position: Int) = list[position]

    override fun getItemId(position: Int) = list[position].report.toLong()

    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
        return (super.getDropDownView(position, convertView, parent) as TextView).apply {
            text = list[position].name
        }
    }

    override fun getDropDownView(position: Int, convertView: View?, parent: ViewGroup): View {
        return (super.getDropDownView(position, convertView, parent) as TextView).apply {
            text = list[position].name
        }
    }
}

并在您的活动/片段中使用它，如下所示：

spinner.adapter = CustomerSalesSpinnerAdapter(
            context,
            R.layout.cuser_spinner_item,
            userList
        )

Answer 11

**Easy & Simple Solution**

overide the below method in model class.


 @NonNull
 @Override
 public String toString() {
  return name; //whatever the value which you want to show in spinner list.
    }

Add the below line to set adapter.

spinner.setAdapter(new ArrayAdapter<ModelClassName>(getContext(),R.layout.item_spinner,list));

Answer 12

我的自定义对象是

/**
 * Created by abhinav-rathore on 08-05-2015.
 */
public class CategoryTypeResponse {
    private String message;

    private int status;

    private Object[] object;

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public int getStatus() {
        return status;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public Object[] getObject() {
        return object;
    }

    public void setObject(Object[] object) {
        this.object = object;
    }

    @Override
    public String toString() {
        return "ClassPojo [message = " + message + ", status = " + status + ", object = " + object + "]";
    }

    public static class Object {
        private String name;
        private String _id;
        private String title;
        private String desc;
        private String xhdpi;
        private String hdpi;
        private String mdpi;
        private String hint;
        private String type;
        private Brands[] brands;


        public String getId() {
            return _id;
        }

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

        public String getName() {
            return name;
        }

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

        public String getXhdpi() {
            return xhdpi;
        }

        public void setXhdpi(String xhdpi) {
            this.xhdpi = xhdpi;
        }

        public String getHdpi() {
            return hdpi;
        }

        public void setHdpi(String hdpi) {
            this.hdpi = hdpi;
        }

        public String getMdpi() {
            return mdpi;
        }

        public void setMdpi(String mdpi) {
            this.mdpi = mdpi;
        }

        public String get_id() {
            return _id;
        }

        public void set_id(String _id) {
            this._id = _id;
        }

        public String getTitle() {
            return title;
        }

        public void setTitle(String title) {
            this.title = title;
        }

        public String getDesc() {
            return desc;
        }

        public void setDesc(String desc) {
            this.desc = desc;
        }

        public String getHint() {
            return hint;
        }

        public void setHint(String hint) {
            this.hint = hint;
        }

        public String getType() {
            return type;
        }

        public void setType(String type) {
            this.type = type;
        }

        public Brands[] getBrands() {
            return brands;
        }

        public void setBrands(Brands[] brands) {
            this.brands = brands;
        }

        @Override
        public String toString() {
            return "ClassPojo [name = " + name + "]";
        }
    }

    public static class Brands {

        private String _id;
        private String name;
        private String value;
        private String categoryid_ref;

        public String get_id() {
            return _id;
        }

        public void set_id(String _id) {
            this._id = _id;
        }

        public String getName() {
            return name;
        }

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

        public String getValue() {
            return value;
        }

        public void setValue(String value) {
            this.value = value;
        }

        public String getCategoryid_ref() {
            return categoryid_ref;
        }

        public void setCategoryid_ref(String categoryid_ref) {
            this.categoryid_ref = categoryid_ref;
        }

        @Override
        public String toString() {
            return  name;

        }
    }
}

我还想将此对象设置为我的微调器的适配器源，而不扩展 ArrayAdapter 所以我所做的是。

brandArray = mCategoryTypeResponse.getObject()[fragPosition].getBrands();

ArrayAdapter brandAdapter = new ArrayAdapter< CategoryTypeResponse.Brands>(getActivity(),
                R.layout.item_spinner, brandArray);

现在您将能够在微调器中看到结果，技巧是在您的自定义对象中重写toString()，因此您想要在微调器中显示的值只需在这个方法中返回它。

Answer 13

如果您不需要单独的类，我的意思是只需映射到您的对象上的简单适配器。
这是我基于提供的 ArrayAdapter 函数的代码。

因为您可能需要在创建适配器后添加项目（例如数据库项目异步加载）。

简单但高效。

editCategorySpinner = view.findViewById(R.id.discovery_edit_category_spinner);

// Drop down layout style - list view with radio button         
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

// attaching data adapter to spinner, as you can see i have no data at this moment
editCategorySpinner.setAdapter(dataAdapter);
final ArrayAdapter<Category> dataAdapter = new ArrayAdapter<Category>

(getActivity(), android.R.layout.simple_spinner_item, new ArrayList<Category>(0)) {


        // And the "magic" goes here
        // This is for the "passive" state of the spinner
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // I created a dynamic TextView here, but you can reference your own  custom layout for each spinner item
            TextView label = (TextView) super.getView(position, convertView, parent);
            label.setTextColor(Color.BLACK);
            // Then you can get the current item using the values array (Users array) and the current position
            // You can NOW reference each method you has created in your bean object (User class)
            Category item = getItem(position);
            label.setText(item.getName());

            // And finally return your dynamic (or custom) view for each spinner item
            return label;
        }

        // And here is when the "chooser" is popped up
        // Normally is the same view, but you can customize it if you want
        @Override
        public View getDropDownView(int position, View convertView,
                                    ViewGroup parent) {
            TextView label = (TextView) super.getDropDownView(position, convertView, parent);
            label.setTextColor(Color.BLACK);
            Category item = getItem(position);
            label.setText(item.getName());

            return label;
        }
    };

然后您可以使用此代码（我无法将 Category[] 放入适配器构造函数中，因为数据是单独加载的）。

请注意，adapter.addAll（items）通过在内部调用notifyDataSetChanged（）来刷新微调器。

categoryRepository.getAll().observe(this, new Observer<List<Category>>() {

            @Override
            public void onChanged(@Nullable final List<Category> items) {
                dataAdapter.addAll(items);
            }
});

Answer 14

我认为最好的解决方案是 “最简单的解决方案” by 乔什·品特。

这对我有用：

//Code of the activity 
//get linearLayout
LinearLayout linearLayout = (LinearLayout ) view.findViewById(R.id.linearLayoutFragment);       

LinearLayout linearLayout = new LinearLayout(getActivity());
//display css
RelativeLayout.LayoutParams params2 = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);

//create the spinner in a fragment activiy
Spinner spn = new Spinner(getActivity());

// create the adapter.
ArrayAdapter<ValorLista> spinner_adapter = new ArrayAdapter<ValorLista>(getActivity(), android.R.layout.simple_spinner_item, meta.getValorlistaList());
spinner_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
spn.setAdapter(spinner_adapter);

//set the default according to value
//spn.setSelection(spinnerPosition);

linearLayout.addView(spn, params2);

//Code of the class ValorLista

import java.io.Serializable;
import java.util.List;

public class ValorLista implements Serializable{


    /**
     * 
     */
    private static final long serialVersionUID = 4930195743192929192L;
    private int id; 
    private String valor;
    private List<Metadato> metadatoList;


    public ValorLista() {
        super();
        // TODO Auto-generated constructor stub
    }

    public int getId() {
        return id;
    }

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

    public String getValor() {
        return valor;
    }
    public void setValor(String valor) {
        this.valor = valor;
    }
    public List<Metadato> getMetadatoList() {
        return metadatoList;
    }
    public void setMetadatoList(List<Metadato> metadatoList) {
        this.metadatoList = metadatoList;
    }

    @Override
    public String toString() {  
        return getValor();
    }

}

Answer 15

做：

spinner.adapter = object: ArrayAdapter<Project>(
            container.context,
            android.R.layout.simple_spinner_dropdown_item,
            state.projects
        ) {
            override fun getDropDownView(
                position: Int,
                convertView: View?,
                parent: ViewGroup
            ): View {
                val label = super.getView(position, convertView, parent) as TextView
                label.text = getItem(position)?.title
                return label
            }

            override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
                val label = super.getView(position, convertView, parent) as TextView
                label.text = getItem(position)?.title
                return label
            }
        }

Answer 16

我知道线程很旧，但以防万一...

用户对象：

public class User{

    private int _id;
    private String _name;

    public User(){
        this._id = 0;
        this._name = "";
    }

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

    public int getId(){
        return this._id;
    }

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

    public String getName(){
        return this._name;
    }
}

自定义微调适配器（ArrayAdapter）

public class SpinAdapter extends ArrayAdapter<User>{

    // Your sent context
    private Context context;
    // Your custom values for the spinner (User)
    private User[] values;

    public SpinAdapter(Context context, int textViewResourceId,
            User[] values) {
        super(context, textViewResourceId, values);
        this.context = context;
        this.values = values;
    }

    @Override
    public int getCount(){
       return values.length;
    }

    @Override
    public User getItem(int position){
       return values[position];
    }

    @Override
    public long getItemId(int position){
       return position;
    }


    // And the "magic" goes here
    // This is for the "passive" state of the spinner
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // I created a dynamic TextView here, but you can reference your own  custom layout for each spinner item
        TextView label = (TextView) super.getView(position, convertView, parent);
        label.setTextColor(Color.BLACK);
        // Then you can get the current item using the values array (Users array) and the current position
        // You can NOW reference each method you has created in your bean object (User class)
        label.setText(values[position].getName());

        // And finally return your dynamic (or custom) view for each spinner item
        return label;
    }

    // And here is when the "chooser" is popped up
    // Normally is the same view, but you can customize it if you want
    @Override
    public View getDropDownView(int position, View convertView,
            ViewGroup parent) {
        TextView label = (TextView) super.getDropDownView(position, convertView, parent);
        label.setTextColor(Color.BLACK);
        label.setText(values[position].getName());

        return label;
    }
}

和实现：

public class Main extends Activity {
    // You spinner view
    private Spinner mySpinner;
    // Custom Spinner adapter (ArrayAdapter<User>)
    // You can define as a private to use it in the all class
    // This is the object that is going to do the "magic"
    private SpinAdapter adapter;

        @Override
        public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // Create the Users array
        // You can get this retrieving from an external source
        User[] users = new User[2];

        users[0] = new User();
        users[0].setId(1);
        users[0].setName("Joaquin");

        users[1] = new User();
        users[1].setId(2);
        users[1].setName("Alberto");

        // Initialize the adapter sending the current context
        // Send the simple_spinner_item layout
        // And finally send the Users array (Your data)
        adapter = new SpinAdapter(Main.this,
            android.R.layout.simple_spinner_item,
            users);
        mySpinner = (Spinner) findViewById(R.id.miSpinner);
        mySpinner.setAdapter(adapter); // Set the custom adapter to the spinner
        // You can create an anonymous listener to handle the event when is selected an spinner item
        mySpinner.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view,
                    int position, long id) {
                // Here you get the current item (a User object) that is selected by its position
                User user = adapter.getItem(position);
                // Here you can do the action you want to...
                Toast.makeText(Main.this, "ID: " + user.getId() + "\nName: " + user.getName(),
                    Toast.LENGTH_SHORT).show();
            }
            @Override
            public void onNothingSelected(AdapterView<?> adapter) {  }
        });
    }
}

Answer 17

最简单的解决方案

在搜索了不同的解决方案后，我发现以下是使用自定义对象填充Spinner的最简单、最干净的解决方案。这是完整的实现：

User.java

public class User{
    public int ID;
    public String name;

    @Override
    public String toString() {
        return this.name; // What to display in the Spinner list.
    }
}    

res/layout/spinner.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:padding="10dp"
    android:textSize="14sp"
    android:textColor="#FFFFFF"
    android:spinnerMode="dialog" />

res/layout/your_activity_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">

    <Spinner android:id="@+id/user" />

</LinearLayout>

在您的活动中

List<User> users = User.all(); // This example assumes you're getting all Users but adjust it for your Class and needs.
ArrayAdapter userAdapter = new ArrayAdapter(this, R.layout.spinner, users);

Spinner userSpinner = (Spinner) findViewById(R.id.user);
userSpinner.setAdapter(userAdapter);
userSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        // Get the value selected by the user
        // e.g. to store it as a field or immediately call a method
        User user = (User) parent.getSelectedItem();
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
    }
});