Toss for many days, and more people crash problems encountered N speechless, but today finally some gains, and this is the first version of the experiment, some confusion, the next step to transform segments, first recorded in the code down here.
Online search a lot of information, are stereotyped found, copy to copy many of the details and did not see the full instance, only a little bit of your own research, the overall feeling android below to display the pictures really easy.
The main functions of the project:
- Asynchronous Load picture
- Picture memory caching, file caching asynchronous disk
- Pictures after solving the misalignment problem using viewHolder
- Scroll through the list to optimize performance, only the visible child pictures
- Without a fixed picture display height, the height of the cache will not change the picture height and flashing when scrolling through the list to make the experience smoother scrolling
- Pictures animated display of results, the newly loaded image shows a transparent Tweening
Not related to the drop-down load and refresh the data, yet to come into contact with these, and has found a custom ListView if there is added at the top and bottom of the load pull data suggest more of view, will lead to the child ListView number and position confusion, Therefore, only the first using a ListView to be a simple effect.
The core is mainly three documents: MainActivity.java, ZAsyncImageLoader.java, DiaryListAdapter.java
Paste the code below:
MainActivity.java
package com.ai9475.meitian;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.Charset;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Looper;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.util.JsonReader;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
import com.ai9475.meitian.adapter.DiaryListAdapter;
import com.ai9475.util.ZAsyncImageLoader;
import com.ai9475.util.ZHttpRequest;
import com.ai9475.util.ZLog;
import com.ai9475.widget.PullToRefreshListView;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.protocol.HTTP;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONStringer;
import org.w3c.dom.Text;
public class MainActivity extends ActionBarActivity
{
private static final String TAG = "MainActivity";
private ListView mDiaryListView;
private DiaryListAdapter mDiaryListAdapter;
private ZAsyncImageLoader mAsyncImageLoader;
private Handler handler = new Handler();
private int endId = 0;
private boolean isScrolling = false;
@Override
protected void onCreate(Bundle savedInstanceState)
{
Log.d("main activity", "start");
// 执行父级初始化方法
super.onCreate(savedInstanceState);
// 让 ActionBar 浮动在 Activity 上方进行半透明遮盖
//this.supportRequestWindowFeature(Window.FEATURE_ACTION_BAR_OVERLAY);
// 解析视图数据
this.setContentView(R.layout.activity_main);
AppManager.getInstance().addActivity(this);
this.mAsyncImageLoader = new ZAsyncImageLoader();
this.mAsyncImageLoader.setIsUseDiskCache(true);
this.mAsyncImageLoader.setCacheDir(AppConfig.IMAGE_CACHE_PATH);
// 配置 ActionBar 相关
final ActionBar bar = this.getSupportActionBar();
// 标题
bar.setTitle("Bar");
// 返回按钮
//bar.setDisplayHomeAsUpEnabled(true);
// 应用徽标控制
//bar.setDisplayUseLogoEnabled(false);
// 应用图标控制
//bar.setDisplayShowHomeEnabled(true);
// 标题栏控制
//bar.setDisplayShowTitleEnabled(true);
// 设置 TABS 导航模式
bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
/*
bar.getHeight();
final ScrollView scrollView = (ScrollView) findViewById(R.id.scrollView);
ViewTreeObserver scvto = scrollView.getViewTreeObserver();
if (scvto != null) {
scvto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
scrollView.setPadding(
scrollView.getPaddingLeft(),
bar.getHeight(),
scrollView.getPaddingRight(),
scrollView.getPaddingBottom()
);
return true;
}
});
}*/
/*Fragment fragmentA = new FragmentTab();
Fragment fragmentB = new FragmentTab();
Fragment fragmentC = new FragmentTab();
tabA.setTabListener(new MyTabsListener(fragmentA));
tabB.setTabListener(new MyTabsListener(fragmentB));
tabC.setTabListener(new MyTabsListener(fragmentC));*/
bar.addTab(bar.newTab().setText("ATab").setTabListener(new MyTabsListener()));
bar.addTab(bar.newTab().setText("BTab").setTabListener(new MyTabsListener()));
bar.addTab(bar.newTab().setText("CTab").setTabListener(new MyTabsListener()));
/*//bar.setDisplayShowHomeEnabled(false);
//bar.setDisplayShowTitleEnabled(false);
// 顶部帧布局操作栏
final FrameLayout topActBar = (FrameLayout) findViewById(R.id.topActionBar);
// 底部帧布局操作栏
final FrameLayout bottomActBar = (FrameLayout) findViewById(R.id.bottomActionBar);
// 列表滚动视图
final ScrollView scrollView = (ScrollView) findViewById(R.id.scrollView);
// 顶部操作栏绑定事件：同步设置滚动视图顶部内边距
topActBar
.getViewTreeObserver()
.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
scrollView.setPadding(
scrollView.getPaddingLeft(),
topActBar.getHeight(),
scrollView.getPaddingRight(),
scrollView.getPaddingBottom()
);
return true;
}
});
// 底部操作栏绑定事件：同步设置滚动视图底部内边距
bottomActBar
.getViewTreeObserver()
.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
scrollView.setPadding(
scrollView.getPaddingLeft(),
scrollView.getPaddingTop(),
scrollView.getPaddingRight(),
bottomActBar.getHeight()
);
return true;
}
});
*/
//AppContext context = (AppContext) getApplicationContext();
//context.test();
/*
ZAsyncImageLoader loader = new ZAsyncImageLoader();
String url1 = "http://img.ai9475.com/data/attachment/images/meitian/c5/e4/59/c5e459f00dce21480c9941eefbb88f90_200.jpg";
String url2 = "http://img.ai9475.com/data/attachment/images/meitian/f9/29/ee/f929ee1dd6af7b805744b9fb3f4f99b5_200.jpg";
loader.loadDrawable(url1, new ZAsyncImageLoader.OnImageLoadListener() {
@Override
public void onLoaded(Drawable imageDrawable, String imageUrl) {
ImageView img = (ImageView) findViewById(R.id.showPic1);
img.setImageDrawable(imageDrawable);
}
});
loader.loadDrawable(url2, new ZAsyncImageLoader.OnImageLoadListener() {
@Override
public void onLoaded(Drawable imageDrawable, String imageUrl) {
ImageView img = (ImageView) findViewById(R.id.showPic2);
img.setImageDrawable(imageDrawable);
}
});*/
// 找到日记列表视图对象
this.mDiaryListView = (ListView) findViewById(R.id.diaryListCt);
new Thread(){
@Override
public void run() {
Runnable runnable = new Runnable() {
@Override
public void run() {
loadDiaryListData();
}
};
handler.post(runnable);
}
}.start();
}
/**
* 日记列表初始化
*/
protected void initDiaryList(JSONArray diaryList)
{
Log.d("initDiaryList", "start");
// 列表单元与数据的适配器生成
this.mDiaryListAdapter = new DiaryListAdapter(this, this.mDiaryListView, this.mAsyncImageLoader, diaryList);
// 绑定列表数据单元适配器
Log.d("initDiaryList", "setAdapter");
this.mDiaryListView.setAdapter(this.mDiaryListAdapter);
Log.d("bindListViewEvents", "start");
// 绑定日记列表事件
this.bindListViewEvents();
Log.d("DiaryListAdapter", "end");
}
static int j = 0;
/**
* 绑定日记列表事件
*/
public void bindListViewEvents()
{
// 列表滚动事件
this.mDiaryListView.setOnScrollListener(new AbsListView.OnScrollListener(){
@Override
public void onScrollStateChanged(AbsListView absListView, int scrollState)
{
switch (scrollState) {
case AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL:
ZLog.i(TAG, "OnScrollListener : SCROLL_STATE_TOUCH_SCROLL");
mDiaryListAdapter.setIsSCrolling(true);
break;
case AbsListView.OnScrollListener.SCROLL_STATE_FLING:
ZLog.i(TAG, "OnScrollListener : SCROLL_STATE_FLING");
mDiaryListAdapter.setIsSCrolling(true);
break;
case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
// 第一个可见 item 的 position
int first = mDiaryListView.getFirstVisiblePosition();
// 最后一个可见 item 的 position
int last = mDiaryListView.getLastVisiblePosition();
// 屏幕上可见 item 的总数
int onScreenCount = mDiaryListView.getChildCount();
int total = first + last;
ZLog.i(TAG, "OnScrollListener : SCROLL_STATE_IDLE => " + (j++) +", first: "+ first +", last: "+ last +", total: "+ total +", onScreenCount:"+ onScreenCount);
mDiaryListAdapter.setIsSCrolling(false);
mDiaryListAdapter.setPositionRange(first, last);
View child;
int position;
for (int i = 0; i < onScreenCount; i++) {
position = first + i;
if (mDiaryListAdapter.isInPrevPositionRange(position)) {
ZLog.i(TAG, "inPrevPositionRange position:"+ position);
continue;
}
// 获取可见 item 子项的视图容器对象
child = mDiaryListView.getChildAt(i);
ImageView picPhoto = (ImageView) child.findViewById(R.id.picPhoto);
ImageView avatar = (ImageView) child.findViewById(R.id.avatar);
try {
ZLog.i(TAG, "load image i:"+ first);
mDiaryListAdapter.loadImage(picPhoto, avatar, mDiaryListAdapter.getItem(position));
} catch (JSONException e) {
AppException.io(e);
}
}
break;
default:
break;
}
}
@Override
public void onScroll(AbsListView absListView, int first, int last, int total) {
//mDiaryListAdapter.setPositionLimit(first, last);
//ZLog.i(TAG, "OnScrollListener : onScroll => " + (j++) +", first: "+ first +", last: "+ last +", total:"+ total);
}
});
// 列表单元点击事件
ZLog.i(TAG, "diaryListInit : setOnItemClickListener");
this.mDiaryListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
getSupportActionBar().setTitle("点击了: "+ i);
}
});
ZLog.i("DiaryListAdapter", "setOnRefreshListener");
// 当向下拉动刷新时触发列表更新事件
/*this.mDiaryListView.setOnRefreshListener(new PullToRefreshListView.OnRefreshListener() {
@Override
public void onRefresh() {
getSupportActionBar().setTitle("执行加载…");
loadDiaryListData();
mDiaryListView.onRefreshComplete();
}
});*/
}
public void loadDiaryListData()
{
ZLog.i(TAG, "loadDiaryListData : start");
try {
ZHttpRequest httpRequset = new ZHttpRequest(new ZHttpRequest.OnHttpRequestListener() {
@Override
public void onRequest(ZHttpRequest request) {
ZLog.i(TAG, "request data : start");
}
@Override
public void onSucceed(int statusCode, ZHttpRequest request) {
// 创建每行数据的集合
ZLog.i(TAG, "request onSucceed : start");
try {
String content = request.getInputStream();
if (content == null) {
Toast.makeText(getApplicationContext(), "数据请求失败", Toast.LENGTH_SHORT).show();
return;
}
JSONArray diaryList = new JSONArray(content);
/*if (asyncImageLoader.getMaxPosition() < 1) {
asyncImageLoader.setPositionLimit(0, diaryList.length());
}*/
endId = ((JSONObject) diaryList.opt(diaryList.length() - 1)).getInt("id");
initDiaryList(diaryList);
} catch (IOException e) {
Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
} catch (JSONException e) {
Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
@Override
public void onFailed(int statusCode, ZHttpRequest request) {
ZLog.i(TAG, "request onFailed : code"+ statusCode);
}
});
httpRequset.get("http://m.ai9475.com/?con=meitian_app&endId=" + this.endId);
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
}
}
protected class MyTabsListener implements ActionBar.TabListener
{
// private Fragment fragment;
// public MyTabsListener(Fragment fragment)
// {
// this.fragment = fragment;
// }
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft)
{
// ft.add(R.id.fragmentPlace, this.fragment, null);
}
@Override
public void onTabReselected(ActionBar.Tab arg0, FragmentTransaction arg1) {
// TODO Auto-generated method stub
}
@Override
public void onTabUnselected(ActionBar.Tab arg0, FragmentTransaction arg1) {
// TODO Auto-generated method stub
}
}
/**
* 配置 ActionBar
*
* @param menu
* @return
*/
public boolean onCreateOptionsMenu(Menu menu)
{
this.getMenuInflater().inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
/*public void doClick(View view)
{
ZHttpRequest get = new ZHttpRequest();
get
.setCharset(HTTP.UTF_8)
.setConnectionTimeout(5000)
.setSoTimeout(5000);
get.setOnHttpRequestListener(new ZHttpRequest.OnHttpRequestListener() {
@Override
public void onRequest(ZHttpRequest request) throws Exception {
}
@Override
public String onSucceed(int statusCode, ZHttpRequest request) throws Exception {
return request.getInputStream();
}
@Override
public String onFailed(int statusCode, ZHttpRequest request) throws Exception {
return "GET 请求失败：statusCode "+ statusCode;
}
});
ZHttpRequest post = new ZHttpRequest();
post
.setCharset(HTTP.UTF_8)
.setConnectionTimeout(5000)
.setSoTimeout(10000);
post.setOnHttpRequestListener(new ZHttpRequest.OnHttpRequestListener() {
private String CHARSET = HTTP.UTF_8;
private ContentType TEXT_PLAIN = ContentType.create("text/plain", Charset.forName(CHARSET));
@Override
public void onRequest(ZHttpRequest request) throws Exception {
// 设置发送请求的 header 信息
request.addHeader("cookie", "abc=123;456=爱就是幸福;");
// 配置要 POST 的数据
MultipartEntityBuilder builder = request.getMultipartEntityBuilder();
builder.addTextBody("p1", "abc");
builder.addTextBody("p2", "中文", TEXT_PLAIN);
builder.addTextBody("p3", "abc中文cba", TEXT_PLAIN);
if (picPath != null && ! "".equals(picPath)) {
builder.addTextBody("pic", picPath);
builder.addBinaryBody("file", new File(picPath));
}
request.buildPostEntity();
}
@Override
public String onSucceed(int statusCode, ZHttpRequest request) throws Exception {
return request.getInputStream();
}
@Override
public String onFailed(int statusCode, ZHttpRequest request) throws Exception {
return "POST 请求失败：statusCode "+ statusCode;
}
});
TextView textView = (TextView) findViewById(R.id.showContent);
String content = "初始内容";
try {
if (view.getId() == R.id.doGet) {
content = get.get("http://www.baidu.com");
content = "GET数据：isGet: " + (get.isGet() ? "yes" : "no") + " =>" + content;
} else {
content = post.post("http://192.168.1.6/test.php");
content = "POST数据：isPost" + (post.isPost() ? "yes" : "no") + " =>" + content;
}
} catch (IOException e) {
content = "IO异常：" + e.getMessage();
} catch (Exception e) {
content = "异常：" + e.getMessage();
}
textView.setText(content);
}
public void doPhoto(View view)
{
destoryBimap();
String state = Environment.getExternalStorageState();
if (state.equals(Environment.MEDIA_MOUNTED)) {
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
startActivityForResult(intent, 1);
} else {
Toast.makeText(MainActivity.this, "没有SD卡", Toast.LENGTH_LONG).show();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
Uri uri = data.getData();
if (uri != null) {
this.photo = BitmapFactory.decodeFile(uri.getPath());
}
if (this.photo == null) {
Bundle bundle = data.getExtras();
if (bundle != null) {
this.photo = (Bitmap) bundle.get("data");
} else {
Toast.makeText(MainActivity.this, "拍照失败", Toast.LENGTH_LONG).show();
return;
}
}
FileOutputStream fileOutputStream = null;
try {
// 获取 SD 卡根目录
String saveDir = Environment.getExternalStorageDirectory() + "/meitian_photos";
// 新建目录
File dir = new File(saveDir);
if (! dir.exists()) dir.mkdir();
// 生成文件名
SimpleDateFormat t = new SimpleDateFormat("yyyyMMddssSSS");
String filename = "MT" + (t.format(new Date())) + ".jpg";
// 新建文件
File file = new File(saveDir, filename);
// 打开文件输出流
fileOutputStream = new FileOutputStream(file);
// 生成图片文件
this.photo.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream);
// 相片的完整路径
this.picPath = file.getPath();
ImageView imageView = (ImageView) findViewById(R.id.showPhoto);
imageView.setImageBitmap(this.photo);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
/**
* 销毁图片文件
*
private void destoryBimap()
{
if (photo != null && ! photo.isRecycled()) {
photo.recycle();
photo = null;
}
}*/
}Android brief analysis of the sequence of events regarding the number of OnScrollListener
ZAsyncImageLoader.java
package com.ai9475.util;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.os.Message;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Date;
import java.util.HashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* 异步多线程加载图片
*
* Created by ZHOUZ on 14-2-7.
*/
public class ZAsyncImageLoader
{
private static final String TAG = "ZAsyncImageLoader";
/**
* 线程池中的线程数量
*/
private int mThreadSize = 5;
/**
* 是否使用 SD 卡缓存图片
*/
private boolean mIsUseDiskCache = false;
/**
* SD 卡上缓存的图片有效期（单位:秒）
*/
private int mExpireTime = 86400;
/**
* 图片缓存文件目录
*/
private String mCachePath = null;
/**
* 同步缓存已加载过的图片，使用软引用优化内存
*/
private HashMap<String, SoftReference<Drawable>> mImageCaches = new HashMap<String, SoftReference<Drawable>>();
/**
* 使用线程池，根据 CPU 数量来动态决定可用线程数量
*/
private ExecutorService mExecutorService = null;
/**
* 设置 SD 卡中的图片缓存有效时长（单位:秒）
*
* @param time
*/
public void setExpireTime(int time) {
this.mExpireTime = time;
}
/**
* 设置线程数量
*
* @param size
*/
public void setThreadSize(int size) {
this.mThreadSize = size;
}
/**
* 设置是否使用 SD 卡缓存图片
*
* @param isUse
*/
public void setIsUseDiskCache(Boolean isUse) {
this.mIsUseDiskCache = isUse;
}
/**
* 设置缓存目录
*
* @param path
*/
public void setCacheDir(String path) {
this.mCachePath = path;
}
/**
* 获取线程池管理器
*
* @return
*/
public ExecutorService getExecutorService() {
if (this.mExecutorService == null) {
if (this.mThreadSize < 1) {
this.mThreadSize = Runtime.getRuntime().availableProcessors() * 5;
}
this.mExecutorService = Executors.newFixedThreadPool(this.mThreadSize);
}
return this.mExecutorService;
}
/**
* 加载图片的多线程控制
*
* @param imageUrl
* @param tag
* @param listener
*/
public Drawable loadDrawable(final String imageUrl, final String tag, final OnImageLoadListener listener)
{
// 是否已缓存过图片, 是则从缓存中直接获取, 若缓存中数据丢失则重新远程加载
if (this.mImageCaches.containsKey(imageUrl)) {
SoftReference<Drawable> softReference = this.mImageCaches.get(imageUrl);
if (softReference != null) {
Drawable drawable = softReference.get();
if (drawable != null) {
return drawable;
}
}
}
// 异步多线程加载图片后的数据传递处理
final Handler handler = new Handler() {
@Override
public void handleMessage(Message message) {
if (message.what == 1) {
listener.onLoaded((Drawable) message.obj, imageUrl, tag);
} else {
listener.onFailed((IOException) message.obj, imageUrl, tag);
}
}
};
// 通过线程池来控制管理图片加载
this.getExecutorService().submit(new Runnable() {
@Override
public void run() {
Message msg;
try {
Drawable drawable = loadImageFromUrl(imageUrl);
mImageCaches.put(imageUrl, new SoftReference<Drawable>(drawable));
msg = handler.obtainMessage(1, drawable);
} catch (IOException e) {
msg = handler.obtainMessage(0, e);
}
handler.sendMessage(msg);
}
});
return null;
}
/**
* 加载远程图片或本地图片缓存文件
*
* @param imageUrl
* @return
* @throws IOException
*/
public Drawable loadImageFromUrl(String imageUrl) throws IOException
{
// 检查 SD 卡是否可用并将图片缓存到 SD 卡上
if (mIsUseDiskCache && mCachePath != null)
{
File d = new File(mCachePath);
if (! d.exists()) {
d.mkdirs();
}
final File f = new File(mCachePath + ZHelper.md5(imageUrl));
long time = (new Date()).getTime();
long expire = time - (mExpireTime * 1000L);
// 文件存在且在有效期内则直接读取
if (f.exists() && f.lastModified() > expire) {
FileInputStream fis = new FileInputStream(f);
return Drawable.createFromStream(fis, "src");
}
// 远程加载图片后写入到 SD 卡上
InputStream i = this.getImageInputStream(imageUrl);
if (i == null) {
return null;
}
final Drawable drawable = Drawable.createFromStream(i, "src");
// 将图片异步写入到本地 SD 卡中缓存, 避免阻塞UI线程, 导致图片不能显示
new Thread(new Runnable() {
@Override
public void run() {
try {
InputStream i = ZFormat.drawable2InputStream(drawable);
DataInputStream in = new DataInputStream(i);
FileOutputStream out = new FileOutputStream(f);
byte[] buffer = new byte[1024];
int byteRead;
while ((byteRead = in.read(buffer)) != -1) {
out.write(buffer, 0, byteRead);
}
in.close();
out.close();
} catch (IOException e) {
ZLog.d("write image cache IOException", e.getMessage());
e.printStackTrace();
}
}
}).start();
return drawable;
}
// 只读取远程图片不缓存
else {
InputStream i = this.getImageInputStream(imageUrl);
return Drawable.createFromStream(i, "src");
}
}
/**
* 远程加载图片数据
*
* @param imageUrl
* @return
* @throws IOException
*/
public InputStream getImageInputStream(String imageUrl) throws IOException
{
URL m = new URL(imageUrl);
HttpURLConnection conn = (HttpURLConnection) m.openConnection();
conn.setRequestMethod("GET");
conn.setUseCaches(false);
conn.setDoInput(true);
conn.setConnectTimeout(5000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
return conn.getInputStream();
}
/**
* 加载图片的事件监听器
*/
public interface OnImageLoadListener {
/**
* 图片加载完成事件处理
*
* @param imageDrawable
* @param imageUrl
* @param tag
*/
public void onLoaded(Drawable imageDrawable, String imageUrl, String tag);
/**
* 图片加载失败的事件处理
*
* @param e
* @param imageUrl
* @param tag
*/
public void onFailed(IOException e, String imageUrl, String tag);
}
protected void finalize()
{
this.mExecutorService.shutdown();
}
}DiaryListAdapter.java
package com.ai9475.meitian.adapter;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.ai9475.meitian.R;
import com.ai9475.util.ZAsyncImageLoader;
import com.ai9475.util.ZHelper;
import com.ai9475.util.ZLog;
import com.ai9475.util.ZUI;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
/**
* Created by ZHOUZ on 14-2-8.
*/
public class DiaryListAdapter extends BaseAdapter implements AbsListView.RecyclerListener
{
private static final String TAG = "DiaryListAdapter";
private Context mContext;
private ListView mDiaryListView;
public View mConvertView;
private ZAsyncImageLoader mAsyncImageLoader;
private JSONArray mDiaryDataList = null;
private boolean mIsScrolling = false;
private int mFirstPosition = 0;
private int mLastPosition = 0;
private int mPrevFirstPosition = 0;
private int mPrevLastPosition = 0;
private HashMap<String, Integer> mImagesHeight = new HashMap<String, Integer>();
public DiaryListAdapter(Context context, ListView listView, ZAsyncImageLoader imageLoader, JSONArray diaryList)
{
this.mContext = context;
this.mAsyncImageLoader = imageLoader;
this.mDiaryDataList = diaryList;
this.mDiaryListView = listView;
}
public void setIsSCrolling(boolean flag)
{
this.mIsScrolling = flag;
}
/**
* 当前列表加载到的日记总数
*
* @return
*/
public int getCount() {
return this.mDiaryDataList == null ? 0 : this.mDiaryDataList.length();
}
/**
* 可见单元位置对比是否处在在上次滚动可是范围内
*
* @param position
* @return
*/
public boolean isInPrevPositionRange(int position) {
// 初始化时直接返回 false
if (this.mPrevLastPosition == 0) return false;
// 检测当前 item 的位置是否在上次滚动范围内, 是则表示该 item 正处于屏幕可见状态中无需重新加载
return (position >= this.mPrevFirstPosition && position <= this.mPrevLastPosition) ? true : false;
}
/**
* 设置滚动后可见的起止项目序号
*
* @param first
* @param last
*/
public void setPositionRange(int first, int last) {
// 保存上次滚动后的可见位置
this.mPrevFirstPosition = this.mFirstPosition;
this.mPrevLastPosition = this.mLastPosition;
// 重置当前可见位置
this.mFirstPosition = first;
this.mLastPosition = last;
ZLog.i(TAG, "setPositionLimit prevFirst: "+ mPrevFirstPosition +", prevLast: "+ mPrevLastPosition +", first: "+ mFirstPosition +", last: "+ mLastPosition);
}
/**
* 获取当前列表单元的日记id
*
* @param position
* @return
*/
public long getItemId(int position) {
int id = 0;
try {
id = this.getItem(position).getInt("id");
} catch (JSONException e) {
Toast.makeText(this.mContext, e.getMessage(), Toast.LENGTH_LONG);
}
return id;
}
/**
* 获取一条数据
*
* @param position
* @return
*/
public JSONObject getItem(int position) {
return (JSONObject) this.mDiaryDataList.opt(position);
}
/**
* 获取视图
*
* @param position
* @param convertView
* @param parent
* @return
*/
public View getView(int position, View convertView, ViewGroup parent)
{
ZLog.v(TAG, "getView i: " + position);
final ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(this.mContext).inflate(R.layout.list_item_diary, null);
this.mConvertView = convertView;
holder = new ViewHolder(convertView);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
try {
// 获取当前列表单元的 JSON 日记数据
JSONObject item = this.getItem(position);
ZLog.i(TAG, "getView i: "+ position +", isScrolling: "+ mIsScrolling +", mFirstPosition: "+ mFirstPosition +", mLastPosition: "+ mLastPosition);
/*if (! isScrolling && (position >= mFirstPosition && position <= mLastPosition)) {
ZLog.i(TAG, "getView i: "+ position +", show images");
this.loadImage(holder.picPhoto, holder.avatar, item);
} else {*/
ZLog.i(TAG, "getView i: "+ position +", can't show images");
// 初始化时自动加载
if (this.mLastPosition == 0) {
this.loadImage(holder.picPhoto, holder.avatar, item);
this.mPrevLastPosition = position;
} else {
this.setDefaultImage(holder.picPhoto, holder.avatar, item);
}
/*holder.picPhoto.setScaleType(ImageView.ScaleType.CENTER);
holder.picPhoto.setImageResource(R.drawable.default_pic);
holder.avatar.setScaleType(ImageView.ScaleType.CENTER);
holder.avatar.setImageResource(R.drawable.default_avatar);
}*/
holder.nickname.setText(item.getString("nickname") +":"+ position);
holder.content.setText(item.getString("content"));
holder.calendarMonth.setText(ZHelper.dateFormat("MM月", item.getInt("calendarDate")));
holder.calendarDay.setText(ZHelper.dateFormat("dd", item.getInt("calendarDate")));
} catch (JSONException e) {
Toast.makeText(this.mContext, e.getMessage(), Toast.LENGTH_LONG);
}
return convertView;
}
public void setDefaultImage(ImageView picPhoto, ImageView avatar, JSONObject item) throws JSONException
{
int height = 0;
String picUrl = getPicUrl(item.getString("picUrl"));
if (mImagesHeight.containsKey(picUrl)) {
height = mImagesHeight.get(picUrl);
}
int minHeight = ZUI.dp2px(this.mContext, 100);
if (height < minHeight) height = minHeight;
picPhoto.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, height));
picPhoto.setScaleType(ImageView.ScaleType.CENTER);
picPhoto.setImageResource(R.drawable.default_pic);
avatar.setScaleType(ImageView.ScaleType.CENTER);
avatar.setImageResource(R.drawable.default_avatar);
}
public String getPicUrl(String pic)
{
return "http://img.ai9475.com/data/attachment/images/meitian/" + pic;
}
public String getAvatarUrl(String avatar)
{
return "http://img.ai9475.com/data/attachment/images/avatar/" + avatar;
}
/**
* 加载可见单元的图片
*
* @param picPhoto
* @param avatar
* @param item
* @throws JSONException
*/
public void loadImage(ImageView picPhoto, ImageView avatar, JSONObject item) throws JSONException
{
// 图片链接
String picUrl = getPicUrl(item.getString("picUrl"));
String avatarUrl = getAvatarUrl(item.getString("avatar"));
// 记录异步加载的图片标签
String picTag = "pic"+ item.getInt("calendarDate") + item.getInt("id");
String avatarTag = "avatar"+ item.getInt("id");
picPhoto.setTag(picTag);
avatar.setTag(avatarTag);
OnPicLoadListener mOnPicLoadListener = new OnPicLoadListener();
OnAvatarLoadListener mOnAvatarLoadListener = new OnAvatarLoadListener();
// 异步加载远程日记照片或缓存
Drawable picDrawable = this.mAsyncImageLoader.loadDrawable(picUrl, picTag, mOnPicLoadListener);
// 存在缓存则使用缓存中的图片资源或者使用默认占位图
mOnPicLoadListener.setDrawable(picPhoto, picUrl, picTag, picDrawable);
// 异步加载远程用户头像或加载缓存
Drawable avatarDrawable = this.mAsyncImageLoader.loadDrawable(avatarUrl, avatarTag, mOnAvatarLoadListener);
// 存在缓存则使用缓存中的图片资源或者使用默认占位图
mOnAvatarLoadListener.setDrawable(avatar, avatarUrl, avatarTag, avatarDrawable);
}
/**
* 当列表单元滚动到可是区域外时清除掉已记录的图片视图
*
* @param view
*/
@Override
public void onMovedToScrapHeap(View view) {
/*ViewHolder holder = (ViewHolder) view.getTag();
this.imageViews.remove(holder.avatar);
this.imageViews.remove(holder.picPhoto);*/
}
private static class ViewHolder
{
public ImageView picPhoto;
public ImageView avatar;
public TextView nickname;
public TextView content;
public TextView calendarMonth;
public TextView calendarDay;
public ViewHolder(View view)
{
this.picPhoto = (ImageView) view.findViewById(R.id.picPhoto);
this.avatar = (ImageView) view.findViewById(R.id.avatar);
this.nickname = (TextView) view.findViewById(R.id.nickname);
this.content = (TextView) view.findViewById(R.id.content);
this.calendarMonth = (TextView) view.findViewById(R.id.calendarMonth);
this.calendarDay = (TextView) view.findViewById(R.id.calendarDay);
}
}
/**
* 头像图片加载事件监听
*/
private class OnAvatarLoadListener extends OnImageLoadListener
{
private int mImageSource = R.drawable.default_avatar;
/**
* 设置图片
*
* @param view
* @param imageUrl
* @param tag
* @param drawable
*/
public void setDrawable(ImageView view, String imageUrl, String tag, Drawable drawable)
{
if (view == null) return;
if (drawable != null) {
view.setScaleType(ImageView.ScaleType.CENTER_CROP);
view.setImageDrawable(drawable);
} else {
view.setScaleType(ImageView.ScaleType.CENTER);
view.setImageResource(this.mImageSource);
}
}
}
/**
* 日记照片加载事件监听
*/
private class OnPicLoadListener extends OnImageLoadListener
{
private int mImageSource = R.drawable.default_pic;
/**
* 设置图片
*
* @param view
* @param imageUrl
* @param tag
* @param drawable
*/
public void setDrawable(ImageView view, String imageUrl, String tag, Drawable drawable)
{
if (view == null) return;
int height = 0;
if (mImagesHeight.containsKey(imageUrl)) {
height = mImagesHeight.get(imageUrl);
}
if (drawable != null) {
// 定义图片的最佳高度
if (height == 0) {
int minHeight = ZUI.dp2px(mContext, 100);
int maxHeight = ZUI.dp2px(mContext, 300);
height = (int) ((float) view.getWidth() / drawable.getMinimumWidth() * drawable.getMinimumHeight());
if (height > maxHeight) {
height = maxHeight;
} else if (height < minHeight) {
height = minHeight;
}
mImagesHeight.put(imageUrl, height);
}
// 现将图片完全透明
drawable.setAlpha(0);
view.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, height));
view.setScaleType(ImageView.ScaleType.CENTER_CROP);
view.setImageDrawable(drawable);
// 添加透明渐变动画显示图片
AlphaAnimation alphaAnim = new AlphaAnimation(0.0f, 1.0f);
alphaAnim.setDuration(1000);
view.setAnimation(alphaAnim);
} else {
int minHeight = ZUI.dp2px(mContext, 100);
height = height < minHeight ? minHeight : height;
view.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, height));
view.setScaleType(ImageView.ScaleType.CENTER);
view.setImageResource(mImageSource);
}
}
}
/**
* 图片的加载监听事件
*/
abstract private class OnImageLoadListener implements ZAsyncImageLoader.OnImageLoadListener
{
/**
* 实现图片显示的抽象方法
*
* @param view
* @param tag
* @param drawable
*/
abstract public void setDrawable(ImageView view, String imageUrl, String tag, Drawable drawable);
@Override
public void onLoaded(Drawable drawable, String imageUrl, String tag) {
ImageView view = (ImageView) mDiaryListView.findViewWithTag(tag == null ? imageUrl : tag);
this.setDrawable(view, imageUrl, tag, drawable);
}
@Override
public void onFailed(IOException e, String imageUrl, String tag) {
//Toast.makeText(mContext, e.toString(), Toast.LENGTH_SHORT).show();
}
}
}Some of the code related to a class method, as well as other aspects relevant blog posts related to the:
some of the data conversion method android
Android achieve 100% ImageView image width and a height in proportion to the width autostretch
Also reminded:
If you encounter position values do not correspond, you may be using a custom ListView, he also added pulling load more children, resulting in the transfer of the ListView and the number of child getView do not correspond in position, I am here to toss only I stumbled across this issue for a long time.
Project Source: http: //yunpan.cn/QpzhBEWCw3gDH
Projects need to modify the address of the server, I accompanied some of the JSON data sent by the server in a compressed package
Reproduced in: https: //my.oschina.net/zhouz/blog/213091