如何使用Hashmap为自定义列表视图创建自定义适配器

debugcn 发表于 Dev

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我如何为该xml创建自定义适配器。有人可以指导我如何创建自定义适配器，也可以给我提供有关如何执行此操作的示例代码。请帮助我，我需要学习如何创建自定义适配器。请帮助我。提前致谢。

这是我的MainActivity.java

package com.example.work.listviewadapter;

import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;
import android.widget.SimpleAdapter;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;


public class MainActivity extends ActionBarActivity {

private static final String PRODUCTLIST_URL ="http://192.168.56.1/productlist.php";


private ProgressDialog pDialog;

public  static  final JSONParser jParser = new JSONParser();

private static final String GET_PRODUCT = "message";

private static final String GET_ID = "ID";

private static final String GET_BRAND = "Brand";

private static final String GET_CATEGORY = "Category";

private static final String GET_DESCRIPTION = "Description";

private static final String GET_CODE = "Code";

private static final String GET_QUANTITY = "Quantity";

private static final String GET_UNIT = "Unit";

private static final String GET_UNITPRICE = "Unitprice";

private JSONArray order = null;

ListView list;
private ArrayList<HashMap<String, String>> orderlist;

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

new LoadComments().execute();


}


public void updateJSONdata() {

    orderlist = new ArrayList<HashMap<String, String>>();


    JSONObject json = jParser.getJSONFromUrl(PRODUCTLIST_URL);


    try {


        order = json.getJSONArray(GET_PRODUCT);

        for (int i = 0; i < order.length(); i++) {

            JSONObject c = order.getJSONObject(i);

            String id = c.getString(GET_ID);

            String brand = c.getString(GET_BRAND);

            String category = c.getString(GET_CATEGORY);

            String description = c.getString(GET_DESCRIPTION);

            String code = c.getString(GET_CODE);

            String quantity = c.getString(GET_QUANTITY);

            String unit = c.getString(GET_UNIT);

            String unitprice = c.getString(GET_UNITPRICE);



            HashMap<String, String> map = new HashMap<String, String>();

            map.put(GET_ID,id);

            map.put(GET_BRAND, brand);

            map.put(GET_CATEGORY, category);

            map.put(GET_DESCRIPTION, description);

            map.put(GET_CODE, code);

            map.put(GET_QUANTITY, quantity);

            map.put(GET_UNIT, unit);

            map.put(GET_UNITPRICE, unitprice);


            orderlist.add(map);

            }

    } catch (JSONException e) {

        e.printStackTrace();

    }

}

private void updateList() {

    //this is for my custom listview

}

final  public class LoadComments extends AsyncTask<Void, Void, Boolean> {

    @Override

    protected void onPreExecute() {

        super.onPreExecute();

        pDialog = new ProgressDialog(MainActivity.this);

        pDialog.setMessage("Loading Order...");

        pDialog.setIndeterminate(false);

        pDialog.setCancelable(true);

        pDialog.show();

    }

    @Override

    protected Boolean doInBackground(Void... arg0) {

        //we will develop this method in version 2

        updateJSONdata();

        return null;

    }

    @Override

    protected void onPostExecute(Boolean result) {

        super.onPostExecute(result);

        pDialog.dismiss();

        //we will develop this method in version 2

        updateList();

    }

}

}

这是我的自定义ListView。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="5dip"
android:background="@drawable/list_selector"
>


<TextView
    android:id="@+id/Quantity"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="10000"
    android:textSize="24dip"
    android:textStyle="bold"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:layout_marginTop="24dp"
    android:layout_marginRight="51dp"
    >
</TextView>

<TextView
    android:id="@+id/Unit"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Gal."
    android:layout_alignParentRight="true"
    android:layout_marginTop="26dp"
    android:textSize="20dp"
    android:layout_marginRight="15dp"
    />

<TextView
    android:id="@+id/Description"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="10dp"
    android:text="White"
    android:textColor="#040404"
    android:typeface="sans"
    android:textSize="20dip"
    android:textStyle="bold"/>

<TextView
    android:id="@+id/Code"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Wpu-01"
    android:layout_marginTop="2dp"
    android:layout_below="@+id/Description"
    android:layout_marginLeft="10dp"/>
<TextView
    android:id="@+id/Brand"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/Code"
    android:layout_marginLeft="10dp"
    android:layout_marginTop="2dp"
    android:text="Weber"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Urethane"
    android:layout_below="@+id/Code"
    android:layout_marginTop="2dp"
    android:layout_toRightOf="@+id/Brand"
    android:layout_marginLeft="5dp"
    android:id="@+id/Category" />
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/Category"
    android:text="P"
    android:layout_marginLeft="12dp"
    android:paddingRight="5dp"
    android:layout_marginTop="2dp"
    android:layout_marginBottom="2dp"
    android:textStyle="italic"
    android:id="@+id/P"
    />
<TextView
    android:id="@+id/Price"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="10000.00"
    android:layout_below="@+id/Brand"
    android:layout_toRightOf="@+id/P"
    android:layout_marginTop="2dp"
    android:layout_marginLeft="2dp"
    />
<TextView
    android:id="@+id/ID"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="11"
    android:layout_alignParentRight="true"
    android:visibility="invisible"
    />
</RelativeLayout>

这对于列表视图

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


<EditText
    android:id="@+id/search"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:hint="Search"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true"
    android:singleLine="true"/>

<ListView
    android:layout_below="@+id/search"
    android:id="@android:id/list"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="#fff"
    android:divider="#ff5873ff"
    android:dividerHeight="3dp" />

德吉什帕特尔

您可以设计BaseAdapter下面的代码，也可以使用ViewHolder模式优化列表视图的性能

private class MyAdapter extends BaseAdapter{
    private LayoutInflater mlayoutInflater;

    public MyAdapter(Context context) {
        mlayoutInflater = LayoutInflater.from(context);  //Dynamic layout mapping
    }

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

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView = mlayoutInflater.inflate(R.layout.listitem, null);  //  According to the layout of the document to instantiate view
        TextView tv = (TextView)convertView.findViewById(R.id.textView);
        tv.setText(orderlist.get(position).get(GET_BRAND).toString());
        return convertView;
    }
}

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