Android：创建一个滑动图像视图
我想制作一个像下面第一张图片一样的滑动图像视图。这些图片将从互联网上下载。在我按下一张图片后，将打开一个类似于第二张图片的活动。我只是要求一个指导方针，因为我是新来的，我不知道如何开始实施。谢谢各位: 第一图像 第二图像Android：创建一个滑动图像视图,android,android-imageview,Android,Android Imageview,我想制作一个像下面第一张图片一样的滑动图像视图。这些图片将从互联网上下载。在我按下一张图片后，将打开一个类似于第二张图片的活动。我只是要求一个指导方针，因为我是新来的，我不知道如何开始实施。谢谢各位: 第一图像 第二图像 以下是在应用程序中滑动多媒体资料的好教程： 以下是在应用程序中滑动多媒体资料的好教程： package com.example.swipableimagegallary import java.util.ArrayList; import android
以下是在应用程序中滑动多媒体资料的好教程：
以下是在应用程序中滑动多媒体资料的好教程： package com.example.swipableimagegallary
import java.util.ArrayList;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
ArrayList<String> arraylist_Url;
Button gallary;
GalleryDialog mGalleryDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gallary=(Button)findViewById(R.id.button_gallary);
arraylist_Url = new ArrayList<String>();
arraylist_Url.add("http://www.akfreshmart.com/AKFresh_ProductImages/494_20-02-2014_Banana_Small_Size.gif");
arraylist_Url.add("http://www.dhresource.com/200x200s/f2-albu-g3-M01-5A-A1-rBVaHFSuM9CAdXH-AAAoSL_PdrY916.jpg/8-7cm-small-size-simulation-foam-pumpkin.jpg");
arraylist_Url.add("http://www.dhresource.com/albu_1066143295_00-1.200x200/middle-size-30cm-and-small-size-20cm-stuffed.jpg");
arraylist_Url.add("http://i.ebayimg.com/images/g/ZpgAAOSwRLZT8EwE/s-l300.jpg");
arraylist_Url.add("http://guideimg.alibaba.com/images/shop/2015/08/14/43/super-mario-bros.-small-size-yoshi-plush-doll_7664843.jpeg");
gallary.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
galleryPopUp();
}
});
}
public void galleryPopUp() {
mGalleryDialog = new GalleryDialog();
mGalleryDialog.show(getFragmentManager(), "dialog");
mGalleryDialog.setCancelable(false);
}
public class GalleryDialog extends DialogFragment {
@SuppressWarnings("deprecation")
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
LayoutInflater inflater = getActivity().getLayoutInflater();
View convertview = inflater.inflate(R.layout.dialog_show_images,
null);
ViewPager viewPager = (ViewPager) convertview
.findViewById(R.id.view_pager);
ImageView imageview_close = (ImageView) convertview
.findViewById(R.id.imageview_close_imageshow);
ImageView imageview_noimage = (ImageView) convertview
.findViewById(R.id.imageview_noimage);
if (arraylist_Url.size() > 0) {
viewPager.setVisibility(View.VISIBLE);
imageview_noimage.setVisibility(View.GONE);
ImageAdapter adapter = new ImageAdapter(getActivity(),
arraylist_Url);
viewPager.setAdapter(adapter);
} else {
viewPager.setVisibility(View.GONE);
imageview_noimage.setVisibility(View.VISIBLE);
imageview_noimage.setBackgroundResource(R.drawable.ic_launcher);
}
imageview_close.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mGalleryDialog.dismiss();
}
});
builder.setView(convertview);
return builder.create();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
**ImageAdapter.java**
package com.example.swipableimagegallary;
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
public class ImageAdapter extends PagerAdapter {
Context context;
LayoutInflater inflater;
ImageLoader imageLoader;
ArrayList<String> arraylist_image_url;
public ImageAdapter(Context context, ArrayList<String> arraylist_image_url) {
this.context = context;
this.arraylist_image_url = arraylist_image_url;
inflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return arraylist_image_url.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
// TODO Auto-generated method stub
return view == ((ViewGroup) object);
}
public class ViewHolder {
TextView textview_count;
ImageView imageview;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
View view = inflater.inflate(R.layout.row_imageadapter, null);
ViewHolder holder = new ViewHolder();
holder.imageview = (ImageView) view
.findViewById(R.id.imageview_machin_image);
holder.textview_count = (TextView) view
.findViewById(R.id.textview_loadingimage);
imageLoader = new ImageLoader(context);
imageLoader.DisplayImage(arraylist_image_url.get(position),
holder.imageview);
holder.textview_count.setText("" + (position + 1) + "/"
+ arraylist_image_url.size());
container.addView(view);
// }
return view;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ViewGroup) object);
}
}
**ImageLoader.java**
package com.example.swipableimagegallary;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.os.Handler;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.Rect;
import android.widget.ImageView;
public class ImageLoader {
Bitmap roundBitmap;
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
Handler handler = new Handler();// handler to display images in UI thread
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.ic_launcher;
public void DisplayImage(String url, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null) {
// roundBitmap=getRoundedShape(bitmap);
imageView.setImageBitmap(bitmap);
} else {
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView) {
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
conn.disconnect();
bitmap = decodeFile(f);
return bitmap;
} catch (Throwable ex) {
ex.printStackTrace();
if (ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
try {
// decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1 = new FileInputStream(f);
BitmapFactory.decodeStream(stream1, null, o);
stream1.close();
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 300;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
FileInputStream stream2 = new FileInputStream(f);
Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
try {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
handler.post(bd);
} catch (Throwable th) {
th.printStackTrace();
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run() {
if (imageViewReused(photoToLoad))
return;
if (bitmap != null) {
// for round image
// roundBitmap=getRoundedShape(bitmap);
photoToLoad.imageView.setImageBitmap(bitmap);
} else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
/** ----Round Image----- **/
public Bitmap getRoundedShape(Bitmap scaleBitmapImage) {
int targetWidth = 400;
int targetHeight = 400;
Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, targetHeight,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(targetBitmap);
Path path = new Path();
path.addCircle(((float) targetWidth - 1) / 2,
((float) targetHeight - 1) / 2,
(Math.min(((float) targetWidth), ((float) targetHeight)) / 2),
Path.Direction.CCW);
canvas.clipPath(path);
Bitmap sourceBitmap = scaleBitmapImage;
canvas.drawBitmap(sourceBitmap, new Rect(0, 0, sourceBitmap.getWidth(),
sourceBitmap.getHeight()), new Rect(0, 0, targetWidth,
targetHeight), null);
return targetBitmap;
}
}
**FileCache.java**
package com.example.swipableimagegallary;
import java.io.File;
import android.content.Context;
public class FileCache {
private File cacheDir;
public FileCache(Context context){
//Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
cacheDir=new File(android.os.Environment.getExternalStorageDirectory(),"LazyList");
else
cacheDir=context.getCacheDir();
if(!cacheDir.exists())
cacheDir.mkdirs();
}
public File getFile(String url){
//I identify images by hashcode. Not a perfect solution, good for the demo.
String filename=String.valueOf(url.hashCode());
//Another possible solution (thanks to grantland)
//String filename = URLEncoder.encode(url);
File f = new File(cacheDir, filename);
return f;
}
public void clear(){
File[] files=cacheDir.listFiles();
if(files==null)
return;
for(File f:files)
f.delete();
}
}
**MemoryCache.java**
package com.example.swipableimagegallary;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import android.graphics.Bitmap;
import android.util.Log;
public class MemoryCache {
private static final String TAG = "MemoryCache";
private Map<String, Bitmap> cache=Collections.synchronizedMap(
new LinkedHashMap<String, Bitmap>(10,1.5f,true));//Last argument true for LRU ordering
private long size=0;//current allocated size
private long limit=1000000;//max memory in bytes
public MemoryCache(){
//use 25% of available heap size
setLimit(Runtime.getRuntime().maxMemory()/4);
}
public void setLimit(long new_limit){
limit=new_limit;
Log.i(TAG, "MemoryCache will use up to "+limit/1024./1024.+"MB");
}
public Bitmap get(String id){
try{
if(!cache.containsKey(id))
return null;
//NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78
return cache.get(id);
}catch(NullPointerException ex){
ex.printStackTrace();
return null;
}
}
public void put(String id, Bitmap bitmap){
try{
if(cache.containsKey(id))
size-=getSizeInBytes(cache.get(id));
cache.put(id, bitmap);
size+=getSizeInBytes(bitmap);
checkSize();
}catch(Throwable th){
th.printStackTrace();
}
}
private void checkSize() {
Log.i(TAG, "cache size="+size+" length="+cache.size());
if(size>limit){
Iterator<Entry<String, Bitmap>> iter=cache.entrySet().iterator();//least recently accessed item will be the first one iterated
while(iter.hasNext()){
Entry<String, Bitmap> entry=iter.next();
size-=getSizeInBytes(entry.getValue());
iter.remove();
if(size<=limit)
break;
}
Log.i(TAG, "Clean cache. New size "+cache.size());
}
}
public void clear() {
try{
//NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78
cache.clear();
size=0;
}catch(NullPointerException ex){
ex.printStackTrace();
}
}
long getSizeInBytes(Bitmap bitmap) {
if(bitmap==null)
return 0;
return bitmap.getRowBytes() * bitmap.getHeight();
}
}
**activity_main.xml**
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.swipableimagegallary.MainActivity" >
<Button
android:id="@+id/button_gallary"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="Button" />
</RelativeLayout>
**dialog_show_images.xml**
<?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:gravity="center"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:background="@android:color/transparent" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="@android:color/holo_blue_light"
android:gravity="center_vertical"
android:orientation="horizontal"
android:padding="5dp" >
<TextView
android:id="@+id/textview_dialog_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
<ImageView
android:id="@+id/imageview_close_imageshow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|center"
android:layout_marginRight="5dp"
android:background="@drawable/close"
android:contentDescription="@null" />
</FrameLayout>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center" >
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_marginBottom="10dp"
android:layout_marginTop="10dp"
android:contentDescription="@null" />
<ImageView
android:id="@+id/imageview_noimage"
android:layout_width="match_parent"
android:layout_height="400dp"
android:layout_gravity="center"
android:layout_margin="20dp"
android:background="@drawable/ic_launcher"
android:contentDescription="@null"
android:visibility="visible" />
</FrameLayout>
</LinearLayout>
</LinearLayout>
**row_imageadapter.xml**
<?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:gravity="center"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="400dp"
android:orientation="vertical" >
<ImageView
android:id="@+id/imageview_machin_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="10dp"
android:contentDescription="@null" />
</LinearLayout>
<TextView
android:id="@+id/textview_loadingimage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
**add following permissions in manifest**
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
import java.util.ArrayList;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
ArrayList<String> arraylist_Url;
Button gallary;
GalleryDialog mGalleryDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gallary=(Button)findViewById(R.id.button_gallary);
arraylist_Url = new ArrayList<String>();
arraylist_Url.add("http://www.akfreshmart.com/AKFresh_ProductImages/494_20-02-2014_Banana_Small_Size.gif");
arraylist_Url.add("http://www.dhresource.com/200x200s/f2-albu-g3-M01-5A-A1-rBVaHFSuM9CAdXH-AAAoSL_PdrY916.jpg/8-7cm-small-size-simulation-foam-pumpkin.jpg");
arraylist_Url.add("http://www.dhresource.com/albu_1066143295_00-1.200x200/middle-size-30cm-and-small-size-20cm-stuffed.jpg");
arraylist_Url.add("http://i.ebayimg.com/images/g/ZpgAAOSwRLZT8EwE/s-l300.jpg");
arraylist_Url.add("http://guideimg.alibaba.com/images/shop/2015/08/14/43/super-mario-bros.-small-size-yoshi-plush-doll_7664843.jpeg");
gallary.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
galleryPopUp();
}
});
}
public void galleryPopUp() {
mGalleryDialog = new GalleryDialog();
mGalleryDialog.show(getFragmentManager(), "dialog");
mGalleryDialog.setCancelable(false);
}
public class GalleryDialog extends DialogFragment {
@SuppressWarnings("deprecation")
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
LayoutInflater inflater = getActivity().getLayoutInflater();
View convertview = inflater.inflate(R.layout.dialog_show_images,
null);
ViewPager viewPager = (ViewPager) convertview
.findViewById(R.id.view_pager);
ImageView imageview_close = (ImageView) convertview
.findViewById(R.id.imageview_close_imageshow);
ImageView imageview_noimage = (ImageView) convertview
.findViewById(R.id.imageview_noimage);
if (arraylist_Url.size() > 0) {
viewPager.setVisibility(View.VISIBLE);
imageview_noimage.setVisibility(View.GONE);
ImageAdapter adapter = new ImageAdapter(getActivity(),
arraylist_Url);
viewPager.setAdapter(adapter);
} else {
viewPager.setVisibility(View.GONE);
imageview_noimage.setVisibility(View.VISIBLE);
imageview_noimage.setBackgroundResource(R.drawable.ic_launcher);
}
imageview_close.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mGalleryDialog.dismiss();
}
});
builder.setView(convertview);
return builder.create();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
**ImageAdapter.java**
package com.example.swipableimagegallary;
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
public class ImageAdapter extends PagerAdapter {
Context context;
LayoutInflater inflater;
ImageLoader imageLoader;
ArrayList<String> arraylist_image_url;
public ImageAdapter(Context context, ArrayList<String> arraylist_image_url) {
this.context = context;
this.arraylist_image_url = arraylist_image_url;
inflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return arraylist_image_url.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
// TODO Auto-generated method stub
return view == ((ViewGroup) object);
}
public class ViewHolder {
TextView textview_count;
ImageView imageview;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
View view = inflater.inflate(R.layout.row_imageadapter, null);
ViewHolder holder = new ViewHolder();
holder.imageview = (ImageView) view
.findViewById(R.id.imageview_machin_image);
holder.textview_count = (TextView) view
.findViewById(R.id.textview_loadingimage);
imageLoader = new ImageLoader(context);
imageLoader.DisplayImage(arraylist_image_url.get(position),
holder.imageview);
holder.textview_count.setText("" + (position + 1) + "/"
+ arraylist_image_url.size());
container.addView(view);
// }
return view;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ViewGroup) object);
}
}
**ImageLoader.java**
package com.example.swipableimagegallary;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.os.Handler;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.Rect;
import android.widget.ImageView;
public class ImageLoader {
Bitmap roundBitmap;
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
Handler handler = new Handler();// handler to display images in UI thread
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.ic_launcher;
public void DisplayImage(String url, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null) {
// roundBitmap=getRoundedShape(bitmap);
imageView.setImageBitmap(bitmap);
} else {
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView) {
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
conn.disconnect();
bitmap = decodeFile(f);
return bitmap;
} catch (Throwable ex) {
ex.printStackTrace();
if (ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
try {
// decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1 = new FileInputStream(f);
BitmapFactory.decodeStream(stream1, null, o);
stream1.close();
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 300;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
FileInputStream stream2 = new FileInputStream(f);
Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
try {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
handler.post(bd);
} catch (Throwable th) {
th.printStackTrace();
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run() {
if (imageViewReused(photoToLoad))
return;
if (bitmap != null) {
// for round image
// roundBitmap=getRoundedShape(bitmap);
photoToLoad.imageView.setImageBitmap(bitmap);
} else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
/** ----Round Image----- **/
public Bitmap getRoundedShape(Bitmap scaleBitmapImage) {
int targetWidth = 400;
int targetHeight = 400;
Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, targetHeight,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(targetBitmap);
Path path = new Path();
path.addCircle(((float) targetWidth - 1) / 2,
((float) targetHeight - 1) / 2,
(Math.min(((float) targetWidth), ((float) targetHeight)) / 2),
Path.Direction.CCW);
canvas.clipPath(path);
Bitmap sourceBitmap = scaleBitmapImage;
canvas.drawBitmap(sourceBitmap, new Rect(0, 0, sourceBitmap.getWidth(),
sourceBitmap.getHeight()), new Rect(0, 0, targetWidth,
targetHeight), null);
return targetBitmap;
}
}
**FileCache.java**
package com.example.swipableimagegallary;
import java.io.File;
import android.content.Context;
public class FileCache {
private File cacheDir;
public FileCache(Context context){
//Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
cacheDir=new File(android.os.Environment.getExternalStorageDirectory(),"LazyList");
else
cacheDir=context.getCacheDir();
if(!cacheDir.exists())
cacheDir.mkdirs();
}
public File getFile(String url){
//I identify images by hashcode. Not a perfect solution, good for the demo.
String filename=String.valueOf(url.hashCode());
//Another possible solution (thanks to grantland)
//String filename = URLEncoder.encode(url);
File f = new File(cacheDir, filename);
return f;
}
public void clear(){
File[] files=cacheDir.listFiles();
if(files==null)
return;
for(File f:files)
f.delete();
}
}
**MemoryCache.java**
package com.example.swipableimagegallary;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import android.graphics.Bitmap;
import android.util.Log;
public class MemoryCache {
private static final String TAG = "MemoryCache";
private Map<String, Bitmap> cache=Collections.synchronizedMap(
new LinkedHashMap<String, Bitmap>(10,1.5f,true));//Last argument true for LRU ordering
private long size=0;//current allocated size
private long limit=1000000;//max memory in bytes
public MemoryCache(){
//use 25% of available heap size
setLimit(Runtime.getRuntime().maxMemory()/4);
}
public void setLimit(long new_limit){
limit=new_limit;
Log.i(TAG, "MemoryCache will use up to "+limit/1024./1024.+"MB");
}
public Bitmap get(String id){
try{
if(!cache.containsKey(id))
return null;
//NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78
return cache.get(id);
}catch(NullPointerException ex){
ex.printStackTrace();
return null;
}
}
public void put(String id, Bitmap bitmap){
try{
if(cache.containsKey(id))
size-=getSizeInBytes(cache.get(id));
cache.put(id, bitmap);
size+=getSizeInBytes(bitmap);
checkSize();
}catch(Throwable th){
th.printStackTrace();
}
}
private void checkSize() {
Log.i(TAG, "cache size="+size+" length="+cache.size());
if(size>limit){
Iterator<Entry<String, Bitmap>> iter=cache.entrySet().iterator();//least recently accessed item will be the first one iterated
while(iter.hasNext()){
Entry<String, Bitmap> entry=iter.next();
size-=getSizeInBytes(entry.getValue());
iter.remove();
if(size<=limit)
break;
}
Log.i(TAG, "Clean cache. New size "+cache.size());
}
}
public void clear() {
try{
//NullPointerException sometimes happen here http://code.google.com/p/osmdroid/issues/detail?id=78
cache.clear();
size=0;
}catch(NullPointerException ex){
ex.printStackTrace();
}
}
long getSizeInBytes(Bitmap bitmap) {
if(bitmap==null)
return 0;
return bitmap.getRowBytes() * bitmap.getHeight();
}
}
**activity_main.xml**
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.swipableimagegallary.MainActivity" >
<Button
android:id="@+id/button_gallary"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="Button" />
</RelativeLayout>
**dialog_show_images.xml**
<?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:gravity="center"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:background="@android:color/transparent" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="@android:color/holo_blue_light"
android:gravity="center_vertical"
android:orientation="horizontal"
android:padding="5dp" >
<TextView
android:id="@+id/textview_dialog_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
<ImageView
android:id="@+id/imageview_close_imageshow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|center"
android:layout_marginRight="5dp"
android:background="@drawable/close"
android:contentDescription="@null" />
</FrameLayout>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center" >
<android.support.v4.view.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_marginBottom="10dp"
android:layout_marginTop="10dp"
android:contentDescription="@null" />
<ImageView
android:id="@+id/imageview_noimage"
android:layout_width="match_parent"
android:layout_height="400dp"
android:layout_gravity="center"
android:layout_margin="20dp"
android:background="@drawable/ic_launcher"
android:contentDescription="@null"
android:visibility="visible" />
</FrameLayout>
</LinearLayout>
</LinearLayout>
**row_imageadapter.xml**
<?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:gravity="center"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="400dp"
android:orientation="vertical" >
<ImageView
android:id="@+id/imageview_machin_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="10dp"
android:contentDescription="@null" />
</LinearLayout>
<TextView
android:id="@+id/textview_loadingimage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
**add following permissions in manifest**
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />