An_ListView 多样展示
2017-08-25 本文已影响9人
android_en
MyApplication类：加载ImageLoader的实现
！！！！别忘了加权限和
在清单里加上MyApplication：
<application
//name---->
android:name="com.example.listview_3item.MyApplication"
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
package com.example.listview_3item;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.DisplayImageOptions.Builder;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;
import android.app.Application;
public class MyApplication extends Application{
@Override
public void onCreate() {
// TODO Auto-generated method stub
DisplayImageOptions options = new DisplayImageOptions.Builder()
.showImageOnLoading(R.drawable.ic_launcher)
.displayer(new FadeInBitmapDisplayer(3000))
.build();
ImageLoaderConfiguration config = ImageLoaderConfiguration.createDefault(this);
ImageLoader.getInstance().init(config);
super.onCreate();
MainActivity 加载图片放到listview
package com.example.listview_3item;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import com.example.listview_3item.bean.Max;
import com.example.listview_3item.bean.news;
import com.google.gson.Gson;
import com.nostra13.universalimageloader.core.ImageLoader;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
public class MainActivity extends Activity {
List<news> list;
private MyAdapter myAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView lv=(ListView) findViewById(R.id.lv);
getData();
myAdapter = new MyAdapter();
lv.setAdapter(myAdapter);
}
private void getData() {
// TODO Auto-generated method stub
new AsyncTask<String, String, String>() {
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
initData();
return null;
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
myAdapter.notifyDataSetChanged();
super.onPostExecute(result);
}
}.execute();
}
protected void initData() {
// TODO Auto-generated method stub
try {
URL url = new URL("http://169.254.122.215:8080/day10/news.json");
HttpURLConnection conn=(HttpURLConnection) url.openConnection();
int code = conn.getResponseCode();
if(code==200){
Gson gson = new Gson();
Max m = gson.fromJson(new InputStreamReader(conn.getInputStream(),"GBK"), Max.class);
list=new ArrayList<news>();
list=m.getData();
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
class MyAdapter extends BaseAdapter{
public static final int TPONE=0;
public static final int TPTWO=1;
public static final int TPTHREE=2;
@Override
public int getCount() {
// TODO Auto-generated method stub
if(list!=null){
return list.size();
}
return 0;
}
//在使用多条目加载的时候 返回当前position对应的类型
//************必须满足的条件 getItemViewType的返回值 必须要小于getViewTypeCount的返回值
@Override
public int getItemViewType(int position) {
// TODO Auto-generated method stub
if(list.get(position).getType()==10001){
return TPONE;
}else if(list.get(position).getType()==10002){
return TPTWO;
}else {
return TPTHREE;
}
}
//使用多条目加载时 一共有几种类型
//从写该方法后，listview控件会知道 当前的布局样式不止一种
//所以 当ListView发现convertview在复用时 类型不配不上时 会重写让convertView加载一遍布局
@Override
public int getViewTypeCount() {
// TODO Auto-generated method stub
return 3;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
ViewHolder0 holder0=null;
ViewHolder1 holder1=null;
ViewHolder2 holder2=null;
int type=getItemViewType(position);
if(convertView==null){
if(type==TPONE){
convertView=View.inflate(MainActivity.this, R.layout.item0,null);
holder0=new ViewHolder0();
holder0.ivleft=(ImageView) convertView.findViewById(R.id.ivleft);
convertView.setTag(holder0);
}else if(type==TPTWO){
convertView=View.inflate(MainActivity.this, R.layout.item1,null);
holder1=new ViewHolder1();
holder1.ivm=(ImageView) convertView.findViewById(R.id.ivm);
convertView.setTag(holder1);
}else{
convertView=View.inflate(MainActivity.this, R.layout.item2,null);
holder2=new ViewHolder2();
holder2.ivright=(ImageView) convertView.findViewById(R.id.ivright);
convertView.setTag(holder2);
}
}else{
if(type==TPONE){
holder0=(ViewHolder0) convertView.getTag();
}else if(type==TPTWO){
holder1=(ViewHolder1) convertView.getTag();
}else if(type==TPTHREE){
holder2=(ViewHolder2) convertView.getTag();
}
}
if(type==TPONE){
ImageLoader.getInstance().displayImage(list.get(position).getPic_url(), holder0.ivleft);
}else if(type==TPTWO){
ImageLoader.getInstance().displayImage(list.get(position).getPic_url(), holder1.ivm);
}else if(type==TPTHREE){
ImageLoader.getInstance().displayImage(list.get(position).getPic_url(), holder2.ivright);
}
return convertView;
}
}
static class ViewHolder0{
ImageView ivleft;
}
static class ViewHolder1{
ImageView ivm;
}
static class ViewHolder2{
ImageView ivright;
}
}
布局 item0
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/ivleft"
android:src="@drawable/ic_launcher"
/>
</LinearLayout>
布局 item1
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/ivm"
android:layout_gravity="center_horizontal"
android:src="@drawable/ic_launcher"
/>
</LinearLayout>
布局 item2
<?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" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/ivright"
android:src="@drawable/ic_launcher"
android:layout_alignParentRight="true"
/>
</RelativeLayout>
}
}
