安卓:如何将微调器绑定到自定义对象列表?
题
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/更改微调器项目时将变量 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!
解决方案
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。
这是重新发布的帖子:
所以如果你来到这里是因为你想在Spinner中同时拥有标签和值 - 这就是我如何做到的:
- 以通常的方式创建
Spinner
- 在
array.xml
文件中定义2个相等大小的数组 - 一个用于标签的数组,一个用于值的数组 - 使用
android:entries =" @ array / labels"
设置 -
当你需要一个值时,做一些这样的事情(不,你不必链接它):
String selectedVal = getResources().getStringArray(R.array.values)[spinner.getSelectedItemPosition()];
醇>
Spinner
其他提示
我知道线程已经老了,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;
}
}
自定义微调器适配器(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;
}
}
实施:
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) { }
});
}
}
最简单的解决方案
在SO上搜索不同的解决方案后,我发现以下是使用自定义 Objects
填充 Spinner
的最简单,最干净的解决方案。这是完整的实施:
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 /布局/ 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 /布局/ 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
// Gets all users but replace with whatever list of users you want.
List<User> users = User.all();
ArrayAdapter userAdapter = new ArrayAdapter(this, R.layout.spinner, users);
Spinner userSpinner = (Spinner) findViewById(R.id.user);
userSpinner.setAdapter(userAdapter);
// And to get the actual User object that was selected, you can do this.
User user = (User) ( (Spinner) findViewById(R.id.user) ).getSelectedItem();
对于简单的解决方案,您只需覆盖“toString”即可。在你的对象
public class User{
public int ID;
public String name;
@Override
public String toString() {
return name;
}
}
然后你可以使用:
ArrayAdapter<User> dataAdapter = new ArrayAdapter<User>(mContext, android.R.layout.simple_spinner_item, listOfUsers);
这样您的微调器就会只显示用户名。
只需对Joaquin Alberto的一个小调整就可以解决样式问题。只需在自定义适配器中替换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;
}
对我来说很好,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
}
});
只需要确保(自己)两个数组中的值正确对齐!
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;
}
}
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(),因此您可以格式化输出。
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;
}
}
另外我认为你可以替换List by Array,所以你不需要在列表中进行toArray,但我有一个List ..... :)
到目前为止,我找到的最简单的方法是:
@Override
public String toString() {
return this.label;
}
现在你可以在你的微调器中粘贴任何对象,它将显示指定的标签。
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,然后这些小部件将在列表或微调器中显示该数据。
所以适配器回答的两个问题是:
- 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?
- 如何从数据结构(您的类的对象)中提取数据以及如何设置字段,即
EditText
根据此数据的小部件或复合视图?
ArrayAdapter的答案是:
- 每个小部件(即
row.xml
或者android.R.layout.simple_spinner_item
) 对于任何索引都是相同的,并且是从其 ID 被赋予 ArrayAdapter 的构造函数的资源中增加的。 - 预计每个小部件将是文本视图(或后代)的实例。小部件的
.setText()
方法将与支持数据结构中的项目的字符串格式一起使用。字符串格式将通过调用.toString()
在该项目上。
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];
}
}
}
适配器内容.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>
主文件
<?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。
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 以便我所做的就是。
brandArray = mCategoryTypeResponse.getObject()[fragPosition].getBrands();
ArrayAdapter brandAdapter = new ArrayAdapter< CategoryTypeResponse.Brands>(getActivity(),
R.layout.item_spinner, brandArray);
现在您将能够在您的微调器中看到结果,诀窍是覆盖自定义对象中的 toString()
,因此您希望显示什么值在微调器中,只需在此方法中返回。
我认为最佳解决方案是”最简单的解决方案“ stackoverflow.com/users/293280/josh-pinter">Josh Pinter 。
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();
}
}
执行:
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
}
}