android中自定义ArrayAdapter中的自定义getFilter

Posted 2023-05-07

【中文标题】android中自定义ArrayAdapter中的自定义getFilter

【英文标题】：Custom getFilter in custom ArrayAdapter in android

【发布时间】：2013-10-08 00:08:53

【问题描述】：

我在自定义 arrayAdapter 中实现自定义 getFilter 时遇到问题。其实我不知道如何实现它。尝试了各种代码，但仍然没有运气。这是我的自定义数组适配器。

package com.test.FilterableList.Adapters;

import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import com.test.FilterableList.Models.ListTO;
import com.test.FilterableList.R;

import android.widget.Filterable;


public class FilterableAdapter extends ArrayAdapter<ListTO> implements Filterable 

    // declaring our ArrayList of items
    public ArrayList<ListTO> objects;

    /* here we must override the constructor for ArrayAdapter
    * the only variable we care about now is ArrayList<Item> objects,
    * because it is the list of objects we want to display.
    */
    public FilterableAdapter(Context context, int textViewResourceId, ArrayList<ListTO> objects) 
        super(context, textViewResourceId, objects);
        this.objects = objects;
    

    /*
     * we are overriding the getView method here - this is what defines how each
     * list item will look.
     */
    public View getView(int position, View convertView, ViewGroup parent)

        // assign the view we are converting to a local variable
        View v = convertView;

        // first check to see if the view is null. if so, we have to inflate it.
        // to inflate it basically means to render, or show, the view.
        if (v == null) 
            LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = inflater.inflate(R.layout.list_item, null);
        

        /*
         * Recall that the variable position is sent in as an argument to this method.
         * The variable simply refers to the position of the current object in the list. (The ArrayAdapter
         * iterates through the list we sent it)
         *
         * Therefore, i refers to the current Item object.
         */
        ListTO i = objects.get(position);

        if (i != null) 

            // This is how you obtain a reference to the TextViews.
            // These TextViews are created in the XML files we defined.

            TextView tt = (TextView) v.findViewById(R.id.list_name);
            if (tt != null)
                tt.setText(i.FileName);
            



        

        // the view must be returned to our activity
        return v;

    

这是 ListTO 类。

package com.test.FilterableList.Models;

public class ListTO 

    public int Id;
    public String FileName;
    public String FileUri;

    public ListTO(int id, String fileName, String fileUri) 

        Id = id;
        FileName = fileName;
        FileUri = fileUri;

    

这是布局。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_
    android:layout_
    android:orientation="vertical"
    android:background="@drawable/blacklikenbackground"
    tools:context=".AllListActivity" >

    <EditText
        android:layout_
        android:layout_
        android:text="Search"
        android:id="@+id/inputSearch"
        />


    <ListView
        android:id="@+id/test_list"
        android:layout_
        android:layout_>
    </ListView>

</LinearLayout>

这里的搜索关键字来自“inputSearch”EditText。

这是文本更改的侦听器。

 inputSearch.addTextChangedListener(new TextWatcher() 

                    @Override
                    public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) 
                        // When user changed the Text
                      //  Toast.makeText(getActivity(), cs.toString(), Toast.LENGTH_LONG).show();
                        m_adapter.getFilter().filter(cs);
                    

                    @Override
                    public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                                                  int arg3) 
                        // TODO Auto-generated method stub

                    

                    @Override
                    public void afterTextChanged(Editable arg0) 
                        // TODO Auto-generated method stub
                    
                );

谢谢。

【问题讨论】：

您到底想达到什么目标？过滤器数据将来自哪里，您希望过滤器做什么？

我还建议您看看这个出色的答案：***.com/a/14369336/72746 - 这可能就是您要找的。​​span>

@Axarydax 抱歉，布局已添加到问题中。实际上 Search 关键字来自“inputSearch”EditText。我想实现谷歌中使用的自动建议功能；但是从列表视图来看。

ArrayAdapter 抽象了所有这些功能，您只需要覆盖 ListTO 上的 toString()。查看它的实现grepcode.com/file/repository.grepcode.com/java/ext/…@chandu tangudu 答案是正确的

【参考方案1】：

您遇到了问题，主要是因为您使用的是自定义对象。如果您将 String 或 int 值传递给数组适配器，它知道如何过滤它。但是，如果您通过自定义对象默认过滤器实现，则不知道如何处理。

虽然尚不清楚您要在过滤器中执行什么操作，但我建议您按照以下步骤操作。

正确实现ListTO，尽管它与您现在的目标无关 实现自定义过滤器 归还您的过滤器

实现自定义过滤器

您要做的第一件事是，来自阵列适配器的implements Filterable。

其次，提供你的Filter的实现

Filter myFilter = new Filter() 
        @Override
        protected FilterResults performFiltering(CharSequence constraint) 
         FilterResults filterResults = new FilterResults();   
         ArrayList<ListTO> tempList=new ArrayList<ListTO>();
         //constraint is the result from text you want to filter against. 
         //objects is your data set you will filter from
         if(constraint != null && objects!=null) 
             int length=objects.size();
             int i=0;
                while(i<length)
                    ListTO item=objects.get(i);
                    //do whatever you wanna do here
                    //adding result set output array     

                    tempList.add(item);

                    i++;
                
                //following two lines is very important
                //as publish result can only take FilterResults objects
                filterResults.values = tempList;
                filterResults.count = tempList.size();
          
          return filterResults;
      

      @SuppressWarnings("unchecked")
      @Override
      protected void publishResults(CharSequence contraint, FilterResults results) 
          objects = (ArrayList<ListTO>) results.values;
          if (results.count > 0) 
           notifyDataSetChanged();
           else 
              notifyDataSetInvalidated();
            
      
     ;

最后一步，

@Override
     public Filter getFilter() 
        return myFilter;
    

【讨论】：

您能帮我解决我的问题吗：***.com/questions/20524417/…。我遵循了该方法，但 ListView 就消失了。

@minhaz 我已经实现了您的解决方案并且效果很好，但是我遇到了一个问题，如果我搜索一个字符串然后将空格返回到空，它不会显示所有数组项.

我也面临同样的问题，当我退格时没有任何效果。

@minhaz 我不明白的一件事是您在publishResults 中重新分配objects，因此您丢失了原始列表？？

这样做：- if (searchquery.length()

【参考方案2】：

无需编写数组适配器。编写一个 toString() 方法，它应该返回文件名的值。

喜欢

public class ListTO 

    public int Id;
    public String FileName;
    public String FileUri;

    public ListTO(int id, String fileName, String fileUri) 

        Id = id;
        FileName = fileName;
        FileUri = fileUri;

    

    public String toString()
        return FileName
    

【讨论】：

如果您只需要基本搜索，这是一个很棒且简单的解决方案。 +1

这不仅仅是伟大的，这是不重新发明***的正确答案

非常适合实现简单搜索

【参考方案3】：

您需要覆盖 Adapter 中的 getFilter() 方法并提供您自己的过滤器。 看看这个Filterable Example 看看实际的实现。

将以下getFilter() 代码添加到您的FilterableAdapter 类中，并用您的过滤器填充它：

/* (non-Javadoc)
 * @see android.widget.ArrayAdapter#getFilter()
 */
@Override
public Filter getFilter() 
    return new Filter() 

        /* (non-Javadoc)
         * @see android.widget.Filter#performFiltering(java.lang.CharSequence)
         */
        @Override
        protected FilterResults performFiltering(CharSequence constraint) 
            // TODO Auto-generated method stub
            /*
             * Here, you take the constraint and let it run against the array
             * You return the result in the object of FilterResults in a form
             * you can read later in publichResults.
             */
            return null;
        

        /* (non-Javadoc)
         * @see android.widget.Filter#publishResults(java.lang.CharSequence, android.widget.Filter.FilterResults)
         */
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) 
            // TODO Auto-generated method stub
            /*
             * Here, you take the result, put it into Adapters array
             * and inform about the the change in data.
             */
        

    ;

我在 cmets 中添加了提示。

【参考方案4】：

试试这个：

     public class Adptr extends BaseAdapter implements Filterable 
public ArrayList<Model> modelValues;

private Activity activity;
private LayoutInflater layoutinflater;
private List<Model> mOriginalValues;
private int PositionSelected = 0;

public Adptr (ArrayList<Model> modelValues, Activity activity) 
    super();
    this.modelValues = modelValues;
    this.activity = activity;




@Override
public int getCount() 

    return modelValues.size();


@Override
public Object getItem(int position) 

    return modelValues.get(position);


@Override
public long getItemId(int position) 

    return position;



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

    layoutinflater = (LayoutInflater)  activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    ViewHolder holder = null;
    Model model = modelValues.get(position);

    if (convertView == null || !(convertView.getTag() instanceof ViewHolder)) 
        convertView = layoutinflater.inflate(R.layout.row_search, null);
        holder = new ViewHolder();
        holder.txtName = (TextView) convertView.findViewById(R.id.row_serch_txt_name);




        convertView.setTag(holder);
        convertView.setTag(R.id.row_serch_txt_name, holder.txtName);

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

    holder.txtArtistName.setText("" + modelValue.get_NAME());




    return convertView;


class ViewHolder 
    TextView txtName;




@Override
public Filter getFilter() 

    Filter filter = new Filter() 

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) 

            modelValues = (ArrayList<ModelValueArtist>) results.values; // has

            notifyDataSetChanged();
        

        @Override
        protected FilterResults performFiltering(CharSequence constraint) 
            FilterResults results = new FilterResults(); // Holds the
                                                            // results of a
                                                            // filtering
                                                            // operation in
                                                            // values
            // List<String> FilteredArrList = new ArrayList<String>();
            List<Model> FilteredArrList = new ArrayList<Model>();

            if (mOriginalValues == null) 
                mOriginalValues = new ArrayList<Model>(modelValues); // saves

            

            /********
             * 
             * If constraint(CharSequence that is received) is null returns
             * the mOriginalValues(Original) values else does the Filtering
             * and returns FilteredArrList(Filtered)
             * 
             ********/
            if (constraint == null || constraint.length() == 0) 

                // set the Original result to return
                results.count = mOriginalValues.size();
                results.values = mOriginalValues;
             else 
                Locale locale = Locale.getDefault();
                constraint = constraint.toString().toLowerCase(locale);
                for (int i = 0; i < mOriginalValues.size(); i++) 
                    Model model = mOriginalValues.get(i);

                    String data = model.get_NAME();
                    if (data.toLowerCase(locale).contains(constraint.toString())) 

                        FilteredArrList.add(modelMyMall);
                    
                
                // set the Filtered result to return
                results.count = FilteredArrList.size();
                results.values = FilteredArrList;

            
            return results;
        
    ;
    return filter;
  

     

【讨论】：

我一个字一个字地用这个词，但没有用。建议覆盖ArrayAdapter 中的getCount()，它只是过滤结果数量而不是结果本身。我在publishResults() 中结束了mThis.clear();mThis.addAll(customList);

【参考方案5】：

您可以在自定义对象类中覆盖 toString() 并返回要过滤掉的 String 对象。

@Override
public void toString()
      return this.toBeFilteredString;

然后简单地使用arrayAdapter的默认内置过滤器并使用它调用它

adapter.getFilter().filter(Charsequence c);

【讨论】：

正是我想要的！ :)

那里也一样！在编写了公认的解决方案后，我寻找了像这样更简单的东西......谢谢！

【参考方案6】：

我在 SO 上搜索了很多答案以获得所需的所有 sn-ps。所以这是我的班级Registration 的自定义过滤器的 Kotlin 版本。 这个确实有效，您需要的所有信息都在此代码中。

class RegistrationArrayAdapter(context: Context, private val layoutResId: Int, registrations: List<Registration>) :
    ArrayAdapter<Registration>(context, layoutResId, registrations) 

    private val filter = RegistrationFilter(registrations)

    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View 
        val registration = getItem(position)
        val view = convertView ?: LayoutInflater.from(context).inflate(layoutResId, null)
        (view as TextView).text = registration?.mainGuest?.name ?: ""
        return view
    

    override fun getFilter() = filter

    inner class RegistrationFilter(private val originalList: List<Registration>) : Filter() 

        private val sourceObjects: ArrayList<Registration> = ArrayList()

        init 
            synchronized (this) 
                sourceObjects.addAll(originalList)
            
        

        override fun performFiltering(constraint: CharSequence?): FilterResults 
            if (constraint == null) return FilterResults()

            val result = FilterResults()

            if (constraint.isNotEmpty()) 
                val filteredList = ArrayList<Registration>()

                sourceObjects.filterTo(filteredList)  isWithinConstraint(it, constraint) 

                result.count = filteredList.size
                result.values = filteredList

             else 
                synchronized(this) 
                    result.values = sourceObjects
                    result.count = sourceObjects.size
                

            
            return result
        

        override fun publishResults(constraint: CharSequence?, results: FilterResults) 
            if (results.values == null) return

            @Suppress("UNCHECKED_CAST")
            val filtered = results.values as ArrayList<Registration>

            if (results.count > 0) 
                clear()
                addAll(filtered)
                notifyDataSetChanged()
             else 
                notifyDataSetInvalidated()
            

        


        override fun convertResultToString(resultValue: Any?): CharSequence 
            return (resultValue as Registration).mainGuest.name
        

        private fun isWithinConstraint(registration: Registration, constraint: CharSequence): Boolean 
            return registration.mainGuest.name.toLowerCase().contains(constraint, true)
        

    

【讨论】：

你是唯一的救星！！没有其他解决方案可以像您那样工作。

【参考方案7】：

正如你所说“我想实现类似谷歌中使用的自动建议功能；但这里是从列表视图中。-重做”

还有另一种方法可以使用 自动完成文本视图

更多详情请通过AutoCompleteTextView

OutPut 将如下所示

ma​​in.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/listitem_layout"
    android:layout_
    android:layout_
    android:background="#e2e2e2"
    android:orientation="vertical" >

    <AutoCompleteTextView
            android:id="@+id/autocomplete"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:background="@drawable/text_area"
            android:inputType="text|textNoSuggestions|textMultiLine"
            android:paddingLeft="10dp"
            android:popupBackground="#EFEEEC"
            android:textColor="#333333"
            android:textColorHint="#9c9c9c"
            android:textSize="18sp"
            android:completionThreshold="1" />

</LinearLayout>

auto_textview.xml

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_
    android:layout_
    android:padding="12dp"
    android:textColor="#333333"
    android:layout_margin="15dp"
    android:textSize="16sp" >
</TextView>

MainActivity.java

public class MainActivity extends Activity 

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        AutoCompleteTextView seachView = (AutoCompleteTextView) findViewById(R.id.autocomplete);
        seachView.setAdapter(new ArrayAdapter<String>(this,
                R.layout.auto_textview, getHeading()));
    

    /**
     * @return
     */
    public List<String> getHeading() 
        List<String> list = new ArrayList<String>();
        list.add("Android");
        list.add("Arnold");
        list.add("Blackberry");
        list.add("Blackpearl");
        list.add("Country");
        list.add("Canada");
        list.add("City");
        list.add("Street Address");
        list.add("Objective C");
        return list;
    

希望这会对你有所帮助。

【讨论】：

你能帮我解决我的问题吗：***.com/questions/20524417/…