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Benutzerdefinierter Adapter für die Listenansicht

Ich möchte einen custom adapter für meine Listenansicht erstellen. Gibt es einen Artikel, der mir zeigen kann, wie man einen erstellt und wie er funktioniert?

205
Harsha M V
public class ListAdapter extends ArrayAdapter<Item> {

    private int resourceLayout;
    private Context mContext;

    public ListAdapter(Context context, int resource, List<Item> items) {
        super(context, resource, items);
        this.resourceLayout = resource;
        this.mContext = context;
    }

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

        View v = convertView;

        if (v == null) {
            LayoutInflater vi;
            vi = LayoutInflater.from(mContext);
            v = vi.inflate(resourceLayout, null);
        }

        Item p = getItem(position);

        if (p != null) {
            TextView tt1 = (TextView) v.findViewById(R.id.id);
            TextView tt2 = (TextView) v.findViewById(R.id.categoryId);
            TextView tt3 = (TextView) v.findViewById(R.id.description);

            if (tt1 != null) {
                tt1.setText(p.getId());
            }

            if (tt2 != null) {
                tt2.setText(p.getCategory().getId());
            }

            if (tt3 != null) {
                tt3.setText(p.getDescription());
            }
        }

        return v;
    }

}

Dies ist eine Klasse, die ich für mein Projekt verwendet hatte. Sie benötigen eine Sammlung Ihrer Artikel, die Sie anzeigen möchten. In meinem Fall ist dies <Item>. Sie müssen die View getView(int position, View convertView, ViewGroup parent)-Methode überschreiben.

R.layout.itemlistrow definiert die Zeile der ListView.

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

    <TableRow Android:layout_width="fill_parent"
              Android:id="@+id/TableRow01"
              Android:layout_height="wrap_content">

        <TextView Android:textColor="#FFFFFF"
                  Android:id="@+id/id"
                  Android:layout_width="fill_parent"
                  Android:layout_height="wrap_content"
                  Android:text="id" Android:textStyle="bold" 
                  Android:gravity="left"
                  Android:layout_weight="1" 
                  Android:typeface="monospace"
                  Android:height="40sp" />
    </TableRow>

    <TableRow Android:layout_height="wrap_content"
              Android:layout_width="fill_parent">

        <TextView Android:textColor="#FFFFFF" 
                  Android:id="@+id/categoryId"
                  Android:layout_width="fill_parent"
                  Android:layout_height="wrap_content"
                  Android:text="categoryId" 
                  Android:layout_weight="1" 
                  Android:height="20sp" />

        <TextView Android:layout_height="wrap_content"
                  Android:layout_width="fill_parent" 
                  Android:layout_weight="1"
                  Android:textColor="#FFFFFF"
                  Android:gravity="right"
                  Android:id="@+id/description"
                  Android:text="description" 
                  Android:height="20sp" />
    </TableRow>

</TableLayout>

In der Variablen MainActivity definieren Sie ListView wie folgt: 

ListView yourListView = (ListView) findViewById(R.id.itemListView);

// get data from the table by the ListAdapter
ListAdapter customAdapter = new ListAdapter(this, R.layout.itemlistrow, List<yourItem>);

yourListView .setAdapter(customAdapter);
292
Rakhita

Ich weiß, dass dies bereits beantwortet wurde ... aber ich wollte ein vollständigeres Beispiel geben.

In meinem Beispiel heißt die ListActivity, die unsere benutzerdefinierte ListView anzeigen wird, OptionsActivity, da diese Activity in meinem Projekt die verschiedenen Optionen anzeigt, die mein Benutzer zur Steuerung meiner App festlegen kann. Es gibt zwei Listenelementtypen, ein Listenelementtyp hat nur eine TextView und der zweite Listenelementtyp hat nur eine Button. Sie können beliebige Widgets in jeden Listenelementtyp einfügen, aber ich habe dieses Beispiel einfach gehalten.

Die getItemView()-Methode prüft, ob die Listenelemente vom Typ 1 oder vom Typ 2 sind. Gemäß meinen statischen Angaben, die ich oben definiert habe, werden die ersten 5 Listenelemente vom Listenelementtyp 1 und die letzten 5 Listenelemente vom Listenelementtyp 2. Wenn Sie das also kompilieren und ausführen, haben Sie eine ListView, die fünf Elemente enthält, die nur eine Button enthalten, und dann fünf Elemente, die nur eine TextView enthalten.

Unten finden Sie den Code Activity, die Aktivitäts-XML-Datei und eine XML-Datei für jeden Listenelementtyp.

OptionsActivity.Java:

public class OptionsActivity extends ListActivity {

    private static final int LIST_ITEM_TYPE_1 = 0;
    private static final int LIST_ITEM_TYPE_2 = 1;
    private static final int LIST_ITEM_TYPE_COUNT = 2;

    private static final int LIST_ITEM_COUNT = 10;
    // The first five list items will be list item type 1 
    // and the last five will be list item type 2
    private static final int LIST_ITEM_TYPE_1_COUNT = 5;

    private MyCustomAdapter mAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mAdapter = new MyCustomAdapter();
        for (int i = 0; i < LIST_ITEM_COUNT; i++) {
          if (i < LIST_ITEM_TYPE_1_COUNT)
            mAdapter.addItem("item type 1");
          else
            mAdapter.addItem("item type 2");
        }
        setListAdapter(mAdapter);
    }

    private class MyCustomAdapter extends BaseAdapter {

        private ArrayList<String> mData = new ArrayList<String>();
        private LayoutInflater mInflater;

        public MyCustomAdapter() {
            mInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }

        public void addItem(final String item) {
            mData.add(item);
            notifyDataSetChanged();
        }

        @Override
        public int getItemViewType(int position) {
          if(position < LIST_ITEM_TYPE_1_COUNT)
              return LIST_ITEM_TYPE_1;
          else
              return LIST_ITEM_TYPE_2;
        }

        @Override
        public int getViewTypeCount() {
            return LIST_ITEM_TYPE_COUNT;
        }

        @Override
        public int getCount() {
            return mData.size();
        }

        @Override
        public String getItem(int position) {
            return mData.get(position);
        }

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

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder = null;
            int type = getItemViewType(position);
            if (convertView == null) {
                holder = new ViewHolder();
                switch(type) {
                    case LIST_ITEM_TYPE_1:
                        convertView = mInflater.inflate(R.layout.list_item_type1, null);
                        holder.textView = (TextView)convertView.findViewById(R.id.list_item_type1_text_view);
                        break;
                    case LIST_ITEM_TYPE_2:
                        convertView = mInflater.inflate(R.layout.list_item_type2, null);
                        holder.textView = (TextView)convertView.findViewById(R.id.list_item_type2_button);
                        break;
                }
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder)convertView.getTag();
            }
            holder.textView.setText(mData.get(position));
            return convertView;
        }

    }

    public static class ViewHolder {
        public TextView textView;
    }

}

activity_options.xml:

<LinearLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
    xmlns:tools="http://schemas.Android.com/tools"
    Android:id="@+id/container"
    Android:layout_width="match_parent"
    Android:layout_height="match_parent"
    Android:orientation="vertical"
     >

    <ListView
        Android:id="@+id/optionsList"
        Android:layout_width="match_parent"
        Android:layout_height="wrap_content" >
    </ListView>

</LinearLayout>

list_item_type_1.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:Android="http://schemas.Android.com/apk/res/Android"
    Android:id="@+id/list_item_type1_layout"
    Android:layout_width="match_parent"
    Android:layout_height="match_parent"
    Android:orientation="vertical" >

    <TextView
        Android:id="@+id/list_item_type1_text_view"
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:text="Text goes here" />

</LinearLayout>

list_item_type2.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:Android="http://schemas.Android.com/apk/res/Android"
    Android:id="@+id/list_item_type2_layout"
    Android:layout_width="match_parent"
    Android:layout_height="match_parent"
    Android:orientation="vertical" >

    <Button
        Android:id="@+id/list_item_type2_button"
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:text="Button text goes here" />

</LinearLayout>
33
Lou Morda

Dieser Code ist leicht zu verstehen.

three_horizontal_text_views_layout.xml

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

    <TextView
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:id="@+id/leftTextView"/>

    <TextView
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:id="@+id/centreTextView"/>

    <TextView
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:id="@+id/rightTextView"/>

</LinearLayout>

ThreeStrings.Java

public class ThreeStrings {
    private String left;
    private String right;
    private String centre;

    public ThreeStrings(String left, String right, String centre) {
        this.left = left;
        this.right = right;
        this.centre = centre;
    }
}

ThreeHorizontalTextViewsAdapter.Java

public class ThreeHorizontalTextViewsAdapter extends ArrayAdapter<ThreeStrings> {

private int layoutResource;

public ThreeHorizontalTextViewsAdapter(Context context, int layoutResource, List<ThreeStrings> threeStringsList) {
    super(context, layoutResource, threeStringsList);
    this.layoutResource = layoutResource;
}

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

    View view = convertView;

    if (view == null) {
        LayoutInflater layoutInflater = LayoutInflater.from(getContext());
        view = layoutInflater.inflate(layoutResource, null);
    }

    ThreeStrings threeStrings = getItem(position);

    if (threeStrings != null) {
        TextView leftTextView = (TextView) view.findViewById(R.id.leftTextView);
        TextView rightTextView = (TextView) view.findViewById(R.id.rightTextView);
        TextView centreTextView = (TextView) view.findViewById(R.id.centreTextView);

        if (leftTextView != null) {
            leftTextView.setText(threeStrings.getLeft());
        }
        if (rightTextView != null) {
            rightTextView.setText(threeStrings.getRight());
        }
        if (centreTextView != null) {
            centreTextView.setText(threeStrings.getCentre());
        }
    }

    return view;
}
      }

main_layout.xml

<LinearLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
    xmlns:tools="http://schemas.Android.com/tools" Android:layout_width="match_parent"
    Android:layout_height="match_parent" Android:paddingLeft="@dimen/activity_horizontal_margin"
    Android:paddingRight="@dimen/activity_horizontal_margin"
    Android:paddingTop="@dimen/activity_vertical_margin"
    Android:paddingBottom="@dimen/activity_vertical_margin"
    Android:orientation="vertical"
    tools:context="com.androidapplication.ListActivity">


    <ListView
        Android:layout_width="match_parent"
        Android:layout_height="wrap_content"
        Android:id="@+id/listView"></ListView>

</LinearLayout>

MainActivity.Java

public class MainActivity extends Activity {


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

        List<ThreeStrings> threeStringsList = new ArrayList<>();
        ThreeStrings threeStrings = new ThreeStrings("a", "b", "c");
        threeStringsList.add(threeStrings);        
        ListView listView = (ListView)findViewById(R.id.listView);
        ThreeHorizontalTextViewsAdapter threeHorizontalTextViewsAdapter = new ThreeHorizontalTextViewsAdapter(this, R.layout.three_horizontal_text_views_layout, threeStringsList);
        listView.setAdapter(threeHorizontalTextViewsAdapter);
      }
   //......}
13
Siddarth Kanted

Google hat ein Beispiel namens EfficientAdapter, das meiner Meinung nach das beste einfache Beispiel für die Implementierung benutzerdefinierter Adapter ist. http://developer.Android.com/resources/samples/ApiDemos/src/com/example/Android/apis/view/List14.html @ CommonsWare hat eine gute Erklärung der verwendeten Muster geschrieben das obige Beispiel http://commonsware.com/Android/excerpt.pdf

10
Marmoy

Sie können this sample in den offiziellen ApiDemos betrachten. Es zeigt, wie Sie BaseAdapter erweitern und auf eine ListView anwenden. Sehen Sie sich anschließend die Referenz für BaseAdapter an und versuchen Sie zu verstehen, was jede Methode (einschließlich der vererbten Methoden) und wann/wie sie verwendet.

Google ist auch dein Freund :).

7
Felix

überprüfe diesen Link , sehr einfach über convertView, wir können das Layout einer Zeile erhalten, die in der Listenansicht angezeigt wird (was parentView ist).

View v = convertView;

if (v == null) {

    LayoutInflater vi;
    vi = LayoutInflater.from(getContext());
    v = vi.inflate(R.layout.itemlistrow, null);

}

Über die Position können Sie die Objekte des List<Item> abrufen.

Item p = items.get(position);

danach müssen wir die gewünschten Details des Objekts auf die identifizierten Formular-Widgets setzen.

if (p != null) {

    TextView tt = (TextView) v.findViewById(R.id.id);
    TextView tt1 = (TextView) v.findViewById(R.id.categoryId);
    TextView tt3 = (TextView) v.findViewById(R.id.description);

    if (tt != null) {
        tt.setText(p.getId());
    }
    if (tt1 != null) {

        tt1.setText(p.getCategory().getId());
    }
    if (tt3 != null) {

        tt3.setText(p.getDescription());
    }
}

dann wird die erstellte Ansicht zurückgegeben, die an parentView angehängt wird (was ein ListView/GridView ist).

6
Rakhita

Hier ist die komplette Anleitung zum Erstellen eines benutzerdefinierten Adapters für die Listenansicht - Schritt für Schritt -

https://www.caveofprogramming.com/guest-posts/custom-listview-mit-imageview-and-textview-in-Android.html

public class CustomAdapter extends BaseAdapter{   
    String [] result;
    Context context;
 int [] imageId;
      private static LayoutInflater inflater=null;
    public CustomAdapter(MainActivity mainActivity, String[] prgmNameList, int[] prgmImages) {
        // TODO Auto-generated constructor stub
        result=prgmNameList;
        context=mainActivity;
        imageId=prgmImages;
         inflater = ( LayoutInflater )context.
                 getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }
    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return result.length;
    }

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

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

    public class Holder
    {
        TextView tv;
        ImageView img;
    }
    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        Holder holder=new Holder();
        View rowView;       
             rowView = inflater.inflate(R.layout.program_list, null);
             holder.tv=(TextView) rowView.findViewById(R.id.textView1);
             holder.img=(ImageView) rowView.findViewById(R.id.imageView1);       
         holder.tv.setText(result[position]);
         holder.img.setImageResource(imageId[position]);         
         rowView.setOnClickListener(new OnClickListener() {            
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Toast.makeText(context, "You Clicked "+result[position], Toast.LENGTH_LONG).show();
            }
        });   
        return rowView;
    }

} 
4

Datenmodell

public class DataModel {
    String name;
    String type;
    String version_number;
    String feature;

    public DataModel(String name, String type, String version_number, String feature ) {
        this.name=name;
        this.type=type;
        this.version_number=version_number;
        this.feature=feature;

    }

    public String getName() {
        return name;
    }

    public String getType() {
        return type;
    }

    public String getVersion_number() {
        return version_number;
    }

    public String getFeature() {
        return feature;
    }    
}

Array-Adapter

public class CustomAdapter extends ArrayAdapter<DataModel> implements View.OnClickListener{
    private ArrayList<DataModel> dataSet;
    Context mContext;

    // View lookup cache
    private static class ViewHolder {
        TextView txtName;
        TextView txtType;
        TextView txtVersion;
        ImageView info;
    }

    public CustomAdapter(ArrayList<DataModel> data, Context context) {
        super(context, R.layout.row_item, data);
        this.dataSet = data;
        this.mContext=context;

    }

    @Override
    public void onClick(View v) {

        int position=(Integer) v.getTag();
        Object object= getItem(position);
        DataModel dataModel=(DataModel)object;

        switch (v.getId())
        {
            case R.id.item_info:
                Snackbar.make(v, "Release date " +dataModel.getFeature(), Snackbar.LENGTH_LONG)
                        .setAction("No action", null).show();
                break;
        }
    }

    private int lastPosition = -1;

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // Get the data item for this position
        DataModel dataModel = getItem(position);
        // Check if an existing view is being reused, otherwise inflate the view
        ViewHolder viewHolder; // view lookup cache stored in tag

        final View result;

        if (convertView == null) {

            viewHolder = new ViewHolder();
            LayoutInflater inflater = LayoutInflater.from(getContext());
            convertView = inflater.inflate(R.layout.row_item, parent, null);
            viewHolder.txtName = (TextView) convertView.findViewById(R.id.name);
            viewHolder.txtType = (TextView) convertView.findViewById(R.id.type);
            viewHolder.txtVersion = (TextView) convertView.findViewById(R.id.version_number);
            viewHolder.info = (ImageView) convertView.findViewById(R.id.item_info);

            result=convertView;

            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
            result=convertView;
        }

        Animation animation = AnimationUtils.loadAnimation(mContext, (position > lastPosition) ? R.anim.up_from_bottom : R.anim.down_from_top);
        result.startAnimation(animation);
        lastPosition = position;

        viewHolder.txtName.setText(dataModel.getName());
        viewHolder.txtType.setText(dataModel.getType());
        viewHolder.txtVersion.setText(dataModel.getVersion_number());
        viewHolder.info.setOnClickListener(this);
        viewHolder.info.setTag(position);
        // Return the completed view to render on screen
        return convertView;
    }
}

Hauptaktivität

public class MainActivity extends AppCompatActivity {

    ArrayList<DataModel> dataModels;
    ListView listView;
    private static CustomAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        listView=(ListView)findViewById(R.id.list);

        dataModels= new ArrayList<>();

        dataModels.add(new DataModel("Apple Pie", "Android 1.0", "1","September 23, 2008"));
        dataModels.add(new DataModel("Banana Bread", "Android 1.1", "2","February 9, 2009"));
        dataModels.add(new DataModel("Cupcake", "Android 1.5", "3","April 27, 2009"));
        dataModels.add(new DataModel("Donut","Android 1.6","4","September 15, 2009"));
        dataModels.add(new DataModel("Eclair", "Android 2.0", "5","October 26, 2009"));
        dataModels.add(new DataModel("Froyo", "Android 2.2", "8","May 20, 2010"));
        dataModels.add(new DataModel("Gingerbread", "Android 2.3", "9","December 6, 2010"));
        dataModels.add(new DataModel("Honeycomb","Android 3.0","11","February 22, 2011"));
        dataModels.add(new DataModel("Ice cream sandwich", "Android 4.0", "14","October 18, 2011"));
        dataModels.add(new DataModel("Jelly bean", "Android 4.2", "16","July 9, 2012"));
        dataModels.add(new DataModel("KitKat", "Android 4.4", "19","October 31, 2013"));
        dataModels.add(new DataModel("Lollipop","Android 5.0","21","November 12, 2014"));
        dataModels.add(new DataModel("Marshmallow", "Android 6.0", "23","October 5, 2015"));

        adapter= new CustomAdapter(dataModels,getApplicationContext());

        listView.setAdapter(adapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                DataModel dataModel= dataModels.get(position);

                Snackbar.make(view, dataModel.getName()+"\n"+dataModel.getType()+" API: "+dataModel.getVersion_number(), Snackbar.LENGTH_LONG)
                        .setAction("No action", null).show();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

row_item.xml

<RelativeLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
    Android:layout_width="match_parent"
    Android:layout_height="wrap_content"
    Android:orientation="vertical"
    Android:padding="10dp">

    <TextView
        Android:id="@+id/name"
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:layout_alignParentTop="true"
        Android:text="Marshmallow"
        Android:textAppearance="?android:attr/textAppearanceSmall"
        Android:textColor="@Android:color/black" />


    <TextView
        Android:id="@+id/type"
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:layout_below="@+id/name"
        Android:layout_marginTop="5dp"
        Android:text="Android 6.0"
        Android:textColor="@Android:color/black" />

    <ImageView
        Android:id="@+id/item_info"
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:layout_alignParentEnd="true"
        Android:layout_alignParentRight="true"
        Android:layout_centerVertical="true"
        Android:src="@Android:drawable/ic_dialog_info" />


    <LinearLayout
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        Android:layout_centerInParent="true">

        <TextView
            Android:id="@+id/version_heading"
            Android:layout_width="wrap_content"
            Android:layout_height="wrap_content"
            Android:text="API: "
            Android:textColor="@Android:color/black"
            Android:textStyle="bold" />

        <TextView
            Android:id="@+id/version_number"
            Android:layout_width="wrap_content"
            Android:layout_height="wrap_content"
            Android:text="23"
            Android:textAppearance="?android:attr/textAppearanceButton"
            Android:textColor="@Android:color/black"
            Android:textStyle="bold" />

    </LinearLayout>

</RelativeLayout>
1
Nilesh Savaliya

Es ist sehr einfach.

import Android.content.Context;
import Android.content.DialogInterface;
import Android.support.annotation.NonNull;
import Android.support.annotation.Nullable;
import Android.support.v7.app.AlertDialog;
import Android.view.LayoutInflater;
import Android.view.View;
import Android.view.ViewGroup;
import Android.widget.ArrayAdapter;
import Android.widget.Button;
import Android.widget.ImageView;
import Android.widget.TextView;

import Java.util.List;

/**
 * Created by Belal on 9/14/2017.
 */

//we need to extend the ArrayAdapter class as we are building an adapter
public class MyListAdapter extends ArrayAdapter<Hero> {

    //the list values in the List of type hero 
    List<Hero> heroList;

    //activity context 
    Context context;

    //the layout resource file for the list items
    int resource;

    //constructor initializing the values 
    public MyListAdapter(Context context, int resource, List<Hero> heroList) {
        super(context, resource, heroList);
        this.context = context;
        this.resource = resource;
        this.heroList = heroList;
    }

    //this will return the ListView Item as a View
    @NonNull
    @Override
    public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) {

        //we need to get the view of the xml for our list item
        //And for this we need a layoutinflater
        LayoutInflater layoutInflater = LayoutInflater.from(context);

        //getting the view
        View view = layoutInflater.inflate(resource, null, false);

        //getting the view elements of the list from the view
        ImageView imageView = view.findViewById(R.id.imageView);
        TextView textViewName = view.findViewById(R.id.textViewName);
        TextView textViewTeam = view.findViewById(R.id.textViewTeam);
        Button buttonDelete = view.findViewById(R.id.buttonDelete);

        //getting the hero of the specified position
        Hero hero = heroList.get(position);

        //adding values to the list item 
        imageView.setImageDrawable(context.getResources().getDrawable(hero.getImage()));
        textViewName.setText(hero.getName());
        textViewTeam.setText(hero.getTeam());

        //adding a click listener to the button to remove item from the list
        buttonDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //we will call this method to remove the selected value from the list
                //we are passing the position which is to be removed in the method 
                removeHero(position);
            }
        });

        //finally returning the view
        return view;
    }

    //this method will remove the item from the list 
    private void removeHero(final int position) {
        //Creating an alert dialog to confirm the deletion
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setTitle("Are you sure you want to delete this?");

        //if the response is positive in the alert 
        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

                //removing the item 
                heroList.remove(position);

                //reloading the list 
                notifyDataSetChanged();
            }
        });

        //if response is negative nothing is being done 
        builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

            }
        });

        //creating and displaying the alert dialog 
        AlertDialog alertDialog = builder.create();
        alertDialog.show();
    }
}

Quelle: Benutzerdefinierte ListView-Anleitung für Android

0
Belal Khan

Ein kompakteres Beispiel eines benutzerdefinierten Adapters (Listenarray als meine Daten verwenden): 

class MyAdapter extends ArrayAdapter<Object> {
    public ArrayAdapter(Context context, List<MyObject> objectList) {
        super(context, R.layout.my_list_item, R.id.textViewTitle, objectList.toArray());
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = super.getView(position, convertView, parent);
        TextView title = (TextView) row.findViewById(R.id.textViewTitle);
        ImageView icon = (ImageView) row.findViewById(R.id.imageViewAccessory);
        MyObject obj = (MyObject) getItem(position);
        icon.setImageBitmap( ... );
        title.setText(obj.name);
        return row;
    }
}

Und so benutzt man es:

List<MyObject> objectList = ...
MyAdapter adapter = new MyAdapter(this.getActivity(), objectList);
listView.setAdapter(adapter);
0
david72

BaseAdapter ist der beste benutzerdefinierte Adapter für Listenansicht.

Class MyAdapter extends BaseAdapter{}

und es hat viele Funktionen wie getCount(), getView() usw.

0
public class CustomAdapter extends BaseAdapter{

    ArrayList<BookPojo> data;
    Context ctx;
    int index=0;

    public CustomAdapter(ArrayList<BookPojo> data, Context ctx) {
        super();
        this.data = data;
        this.ctx = ctx;
    }

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

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

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

    @Override
    public View getView(int position, View convertview, ViewGroup parent) {
        // TODO Auto-generated method stub
        View v=convertview;

        if(v==null){
            LayoutInflater vi=LayoutInflater.from(ctx);
            v=vi.inflate(R.layout.messgeview,null);

        }

        RelativeLayout rlmessage=(RelativeLayout)v.findViewById(R.id.rlmessgeview);

        TextView tvisdn=(TextView)v.findViewById(R.id.tvisdn);
        TextView tvtitle=(TextView)v.findViewById(R.id.tvtitle);
        TextView tvauthor=(TextView)v.findViewById(R.id.tvauthor);
        TextView tvprice=(TextView)v.findViewById(R.id.tvprice);

        BookPojo bpj=data.get(position);

        tvisdn.setText(bpj.isdn+"");
        tvtitle.setText(bpj.title);
        tvauthor.setText(bpj.author);
        tvprice.setText(bpj.price+"");

        if(index%2==0)
        {
            rlmessage.setBackgroundColor(Color.BLUE);
        }
        else
        {
            rlmessage.setBackgroundColor(Color.YELLOW);

        }

        index++;

        return v;
    }
}
0
Hardik Karkar