Java 在listview中缓存json中的图像?
我上了这节课,讲的是json解析和列表视图中的图像加载。这个例子很好,但是在imageview中,当上下滚动所有图像时,它有一个问题,所以有人能解决这个问题吗 这是listview的适配器Java 在listview中缓存json中的图像?,java,android,json,Java,Android,Json,我上了这节课,讲的是json解析和列表视图中的图像加载。这个例子很好,但是在imageview中,当上下滚动所有图像时,它有一个问题,所以有人能解决这个问题吗 这是listview的适配器 package com.wingnity.jsonparsingtutorial; import java.io.InputStream; import java.util.ArrayList; import android.content.Context; import android.grap
package com.wingnity.jsonparsingtutorial;
import java.io.InputStream;
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class ActorAdapter extends ArrayAdapter<Actors> {
ArrayList<Actors> actorList;
LayoutInflater vi;
int Resource;
ViewHolder holder;
public ActorAdapter(Context context, int resource, ArrayList<Actors> objects) {
super(context, resource, objects);
vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
Resource = resource;
actorList = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// convert view = design
View v = convertView;
if (v == null) {
holder = new ViewHolder();
v = vi.inflate(Resource, null);
holder.imageview = (ImageView) v.findViewById(R.id.ivImage);
holder.tvName = (TextView) v.findViewById(R.id.tvName);
holder.tvDescription = (TextView) v.findViewById(R.id.tvDescriptionn);
holder.tvDOB = (TextView) v.findViewById(R.id.tvDateOfBirth);
holder.tvCountry = (TextView) v.findViewById(R.id.tvCountry);
holder.tvHeight = (TextView) v.findViewById(R.id.tvHeight);
holder.tvSpouse = (TextView) v.findViewById(R.id.tvSpouse);
holder.tvChildren = (TextView) v.findViewById(R.id.tvChildren);
v.setTag(holder);
} else {
holder = (ViewHolder) v.getTag();
}
holder.imageview.setImageResource(R.drawable.ic_launcher);
new DownloadImageTask(holder.imageview).execute(actorList.get(position).getImage());
holder.tvName.setText(actorList.get(position).getName());
holder.tvDescription.setText(actorList.get(position).getDescription());
holder.tvDOB.setText("B'day: " + actorList.get(position).getDob());
holder.tvCountry.setText(actorList.get(position).getCountry());
holder.tvHeight.setText("Height: " + actorList.get(position).getHeight());
holder.tvSpouse.setText("Spouse: " + actorList.get(position).getSpouse());
holder.tvChildren.setText("Children: " + actorList.get(position).getChildren());
return v;
}
static class ViewHolder {
public ImageView imageview;
public TextView tvName;
public TextView tvDescription;
public TextView tvDOB;
public TextView tvCountry;
public TextView tvHeight;
public TextView tvSpouse;
public TextView tvChildren;
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
}
package com.wingnity.jsonparsingtutorial;
导入java.io.InputStream;
导入java.util.ArrayList;
导入android.content.Context;
导入android.graphics.Bitmap;
导入android.graphics.BitmapFactory;
导入android.os.AsyncTask;
导入android.util.Log;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.ArrayAdapter;
导入android.widget.ImageView;
导入android.widget.TextView;
公共类ActoradPter扩展ArrayAdapter{
ArrayList actorList;
拉平机vi;
智力资源;
视窗座;
公共Actorapter(上下文、int资源、ArrayList对象){
超级(上下文、资源、对象);
vi=(LayoutInflater)context.getSystemService(context.LAYOUT\u充气机\u服务);
资源=资源;
actorList=对象;
}
@凌驾
公共视图getView(int位置、视图转换视图、视图组父视图){
//转换视图=设计
视图v=转换视图;
如果(v==null){
holder=新的ViewHolder();
v=vi.充气(资源,空);
holder.imageview=(imageview)v.findViewById(R.id.ivImage);
holder.tvName=(TextView)v.findViewById(R.id.tvName);
holder.tvDescription=(TextView)v.findViewById(R.id.tvDescriptionn);
holder.tvDOB=(TextView)v.findviewbyd(R.id.tvDateOfBirth);
holder.tvCountry=(TextView)v.findViewById(R.id.tvCountry);
holder.tvHeight=(TextView)v.findViewById(R.id.tvHeight);
holder.TVparty=(TextView)v.findViewById(R.id.TVparty);
holder.tvChildren=(TextView)v.findViewById(R.id.tvChildren);
v、 setTag(支架);
}否则{
holder=(ViewHolder)v.getTag();
}
holder.imageview.setImageResource(R.drawable.ic_启动器);
新建下载的ImageTask(holder.imageview).execute(actorList.get(position.getImage());
holder.tvName.setText(actorList.get(position.getName());
holder.tvDescription.setText(actorList.get(position.getDescription());
holder.tvDOB.setText(“B'day:+actorList.get(position.getDob());
holder.tvCountry.setText(actorList.get(position.getCountry());
holder.tvHeight.setText(“高度:+actorList.get(位置).getHeight());
holder.tvpament.setText(“配偶:+actorList.get(position.getspament());
holder.tvChildren.setText(“Children:+actorList.get(position.getChildren());
返回v;
}
静态类视窗夹{
公共影像视图;
公共文本视图tvName;
公共文本视图描述;
公共文本视图tvDOB;
公共文本视图;
公共文本视图高度;
公共文本视图;
公共文本视图;
}
私有类DownloadImageTask扩展了AsyncTask{
图像视图bmImage;
公共下载ImageTask(ImageView bmImage){
this.bmImage=bmImage;
}
受保护位图doInBackground(字符串…URL){
字符串urldisplay=url[0];
位图mIcon=null;
试一试{
InputStream in=newjava.net.URL(urldisplay.openStream();
mIcon=BitmapFactory.decodeStream(in);
}捕获(例外e){
Log.e(“Error”,e.getMessage());
e、 printStackTrace();
}
返回mIcon;
}
受保护的void onPostExecute(位图结果){
bmImage.setImageBitmap(结果);
}
}
}
使用了Android通用图像加载程序这是最好的
申报
论创造
此处没有图像缓存中没有任何图像加载的可绘制图像
您也可以使用Piccaso和Glide这是编辑后的代码,它工作起来很有魅力
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;
public class ActorAdapter extends BaseAdapter {
private Activity activity;
private LayoutInflater inflater;
private List<Actors> movieItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public ActorAdapter(Activity activity, List<Actors> movieItems) {
this.activity = activity;
this.movieItems = movieItems;
}
@Override
public int getCount() {
return movieItems.size();
}
@Override
public Object getItem(int location) {
return movieItems.get(location);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.list_item, null);
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
NetworkImageView thumbNail = (NetworkImageView) convertView
.findViewById(R.id.flag);
TextView title = (TextView) convertView.findViewById(R.id.rank);
// getting movie data for the row
Actors m = movieItems.get(position);
// thumbnail image
thumbNail.setImageUrl(m.getImage(), imageLoader);
// title
title.setText(m.getName());
return convertView;
}
}
import java.util.List;
导入android.app.Activity;
导入android.content.Context;
导入android.view.LayoutInflater;
导入android.view.view;
导入android.view.ViewGroup;
导入android.widget.BaseAdapter;
导入android.widget.TextView;
导入com.android.volley.toolbox.ImageLoader;
导入com.android.volley.toolbox.NetworkImageView;
公共类Actorapter扩展了BaseAdapter{
私人活动;
私人充气机;
私人电影项目清单;
ImageLoader ImageLoader=AppController.getInstance().getImageLoader();
公共Actorapter(活动,列出电影项目){
这个。活动=活动;
this.movieItems=movieItems;
}
@凌驾
public int getCount(){
返回movieItems.size();
}
@凌驾
公共对象getItem(int位置){
返回电影项目。获取(位置);
}
@凌驾
公共长getItemId(int位置){
返回位置;
}
@凌驾
公共视图getView(int位置、视图转换视图、视图组父视图){
如果(充气器==null)
充气器=(充气器)活动
.getSystemService(上下文布局\充气机\服务);
if(convertView==null)
convertView=充气机。充气(R.layout.list_项,空);
如果(imageLoader==null)
imageLoader=AppController.getInstance().getImageLoader();
NetworkImageView缩略图=(NetworkImageView)convertView
.findviewbyd(R.id.flag);
TextView title=(TextView)convertView.findViewById(R.id.rank);
//正在获取行的电影数据
Actors m=movieItems.get(位置);
//缩略图像
缩略图.setImag
imageLoader1 = ImageLoader.getInstance();
imageLoader1.init(ImageLoaderConfiguration.createDefault(getActivity()));
DisplayImageOptions
options = new DisplayImageOptions.Builder()
.cacheInMemory(true)
.cacheOnDisk(true)
.showImageOnLoading(R.drawable.no_image) // resource or drawable
.showImageForEmptyUri(R.drawable.no_image) // resource or drawable
.showImageOnFail(R.drawable.no_image)
.considerExifParams(true)
.bitmapConfig(Bitmap.Config.RGB_565)
.build();
imageLoader1.displayImage(yourpath.replace(" ", "%20"), ivprofile, options);
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;
public class ActorAdapter extends BaseAdapter {
private Activity activity;
private LayoutInflater inflater;
private List<Actors> movieItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public ActorAdapter(Activity activity, List<Actors> movieItems) {
this.activity = activity;
this.movieItems = movieItems;
}
@Override
public int getCount() {
return movieItems.size();
}
@Override
public Object getItem(int location) {
return movieItems.get(location);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.list_item, null);
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
NetworkImageView thumbNail = (NetworkImageView) convertView
.findViewById(R.id.flag);
TextView title = (TextView) convertView.findViewById(R.id.rank);
// getting movie data for the row
Actors m = movieItems.get(position);
// thumbnail image
thumbNail.setImageUrl(m.getImage(), imageLoader);
// title
title.setText(m.getName());
return convertView;
}
}