在qq空间或者微信朋友圈里 看到图片总会点击图片进行查看，图片放大缩小功能包括通过手势放大缩小旋转以及双击放大缩小，并且可以左右滑动看到前一张图片或者后一张图片，需要该功能的话，这篇文章或许可以给你帮助。
众所周知，imageloader异步加载图片，不仅可以快速加载图片，而且还可以将图片保存到sdk缓存中，因此下载图片用imageloader即可，如有不懂的，可简单看下我的这篇文章http://blog.csdn.net/u012303938/article/details/46330123，scaleimageview网上流行的一个继续于imageview的封装可以放大缩小的view，viewpager是可以实现左右滑动v4jar包中的类。
demo下载地址http://download.csdn.net/detail/u012303938/8764507
本demo实现了一个简单的相册功能，点击相册，异步加载所有图片，点击图片查看，左右滑动上下张，可手势放大缩小查看的图片。
上代码
BaseAvtivity
package com.example.image;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
public abstract class BaseActivity extends Activity{
protected void onCreate(Bundle savedInstanceState,int layoutResID) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(layoutResID);
findView();
addListenr();
}
public abstract void findView();
public abstract void addListenr();
}
主要的mianactivti继承与baseactivity
package com.example.image;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import com.nostra13.universalimageloader.core.ImageLoader;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
public class MainActivity extends BaseActivity {
private Button btn_dl,tv_left;
private ListView lv;
private Context context;
private TextView tv_tt;
private ArrayList<Map<String, Object>> list=new ArrayList<Map<String,Object>>();
String[] imageUrls = new String[] {
"http://file.bmob.cn/M00/D9/44/oYYBAFSGZlyAXZjwAAC5ynS9Zww4985471",
"http://file.bmob.cn/M00/D8/8F/oYYBAFSFh_WAB_uIAAB4PTlS6rI0966668",};
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState,R.layout.activity_main);
loadData();
}
private void loadData() {
// TODO Auto-generated method stub
for(int i=0;i<imageUrls.length;i++){
Map<String, Object> map=new HashMap<String, Object>();
map.put("text", "我的相册"+i+"张");
list.add(map);
}
MyAdapter adapter=new MyAdapter();
lv.setAdapter(adapter);
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
startActivity(new Intent(context,PhotoGlDetail.class));
}
});
}
@Override
public void findView() {
// TODO Auto-generated method stub
context=this;
lv=(ListView) findViewById(R.id.lv);
}
@Override
public void addListenr() {
// TODO Auto-generated method stub
}
private class MyAdapter extends BaseAdapter{
class HolderView {
public ImageView imageView1;
public TextView textView1;
}
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return list.get(arg0);
}
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return arg0;
}
public View getView(int position, View converView, ViewGroup arg2) {
// TODO Auto-generated method stub
HolderView holderView=null;
if(converView==null){
holderView=new HolderView();
converView=View.inflate(context, R.layout.photo_item, null);
holderView.textView1=(TextView) converView.findViewById(R.id.textView1);
holderView.imageView1=(ImageView) converView.findViewById(R.id.imageView1);
converView.setTag(holderView);
}else{
holderView=(HolderView) converView.getTag();
}
holderView.textView1.setText(list.get(position).get("text").toString());
ImageLoader.getInstance().displayImage(imageUrls[position], holderView.imageView1);
return converView;
}
}
}
Tapplication继承的application
package com.example.image;
import java.io.File;
import com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.QueueProcessingType;
import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer;
import com.nostra13.universalimageloader.utils.StorageUtils;
import android.app.Application;
import android.content.Context;
public class TAppliacation extends Application{
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
File cacheDir = StorageUtils.getOwnCacheDirectory(getApplicationContext(), "imageloader/Cache");
DisplayImageOptions defaultOptions = new DisplayImageOptions
.Builder()
.showImageForEmptyUri(R.drawable.ic_empty)
.showImageOnFail(R.drawable.ic_error)
.cacheInMemory(true)
.cacheOnDisc(true)
.considerExifParams(true)
.build();
ImageLoaderConfiguration config = new ImageLoaderConfiguration
.Builder(getApplicationContext())
.discCache(new UnlimitedDiscCache(cacheDir))
.defaultDisplayImageOptions(defaultOptions)
.discCacheSize(50 * 1024 * 1024)//
.discCacheFileCount(100)//
.threadPriority(Thread.NORM_PRIORITY - 2)
.denyCacheImageMultipleSizesInMemory()
.tasksProcessingOrder(QueueProcessingType.LIFO)
.writeDebugLogs()
.build();
ImageLoader.getInstance().init(config);
}
}
异步加载所有图片phtogldetail
package com.example.image;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer;
/*
* @author CarrayDraw
* @time 2015-6-1
* 照片详细
*/
public class PhotoGlDetail extends BaseActivity{
private ArrayList<Map<String, Object>> list=new ArrayList<Map<String,Object>>();
private GridView gridView1;
private Context context;
private ArrayList<byte[]> lbyte=new ArrayList<byte[]>();
DisplayImageOptions options;
//private NormalLoadPictrue loadPictrue;
public static String[] imageUrls = new String[] {
"http://file.bmob.cn/M00/D8/8F/oYYBAFSFh_WAB_uIAAB4PTlS6rI0966668",
"http://file.bmob.cn/M00/D7/56/oYYBAFSBhJSAIdIJAACoNxTDcM44444974",
"http://file.bmob.cn/M00/D9/45/oYYBAFSGZvKAdpqWAACKHHYyClU0459660",
"http://file.bmob.cn/M00/D9/45/oYYBAFSGZreAEyRSAADfcLFM62U5428980",
"http://file.bmob.cn/M00/D9/44/oYYBAFSGZlyAXZjwAAC5ynS9Zww4985471",
"http://file.bmob.cn/M00/D9/44/oYYBAFSGZYqAUYxAAADSNZMdbOs5036914",
"http://file.bmob.cn/M00/D9/43/oYYBAFSGZRCATj2XAADDaZB1Nbo6433800",
"http://file.bmob.cn/M00/D9/41/oYYBAFSGZJKAWXyDAADPOI8iH6Q3523485",
"http://file.bmob.cn/M00/D8/8F/oYYBAFSFiE6AbAu2AACfguCRGHY3486277",
"http://file.bmob.cn/M00/D7/57/oYYBAFSBhd-Aa1IiAAC86WAfmc89917549",
"http://file.bmob.cn/M00/D7/55/oYYBAFSBgiKAC2aGAAC4We1hZmk1405980",
"http://file.bmob.cn/M00/D7/56/oYYBAFSBgrmAXQ8BAAD665llCTc5545260",
"http://file.bmob.cn/M00/D7/56/oYYBAFSBg-CAePQKAAC38mflwMY8903422"};
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState,R.layout.photodetail);
options = new DisplayImageOptions.Builder()
.showImageOnLoading(R.drawable.ic_launcher)
.showImageForEmptyUri(R.drawable.ic_empty)
.showImageOnFail(R.drawable.ic_error).cacheInMemory(true)
.cacheOnDisc(true).considerExifParams(true)
.displayer(new RoundedBitmapDisplayer(20)).build();
loadData();
}
private void loadData() {
// TODO Auto-generated method stub
for(int i=0;i<imageUrls.length;i++){
Map<String, Object> map=new HashMap<String, Object>();
map.put("img", imageUrls[i]);
list.add(map);
}
MyAdapter adapter=new MyAdapter();
gridView1.setAdapter(adapter);
gridView1.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position,
long arg3) {
// TODO Auto-generated method stub
Intent intent=new Intent(context,HeadPortrait.class);
intent.putExtra("bitmap", lbyte);
intent.putExtra("pos", position);
startActivity(intent);
}
});
}
@Override
public void findView() {
// TODO Auto-generated method stub
context=this;
// loadPictrue=new NormalLoadPictrue();
gridView1=(GridView) findViewById(R.id.gridView1);
}
private class MyAdapter extends BaseAdapter{
class HolderView {
public ImageView imageView1;
}
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return list.get(arg0);
}
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return arg0;
}
public View getView(final int position, View converView, ViewGroup arg2) {
// TODO Auto-generated method stub
HolderView holderView=null;
if(converView==null){
holderView=new HolderView();
converView=View.inflate(context,R.layout.photodetail_item, null);
holderView.imageView1=(ImageView) converView.findViewById(R.id.imageView1);
converView.setTag(holderView);
}else{
holderView=(HolderView) converView.getTag();
}
//loadPictrue.getPicture(imageUrls[position], holderView.imageView1);
ImageLoader.getInstance().displayImage(imageUrls[position], holderView.imageView1,options);
return converView;
}
}
@Override
public void addListenr() {
// TODO Auto-generated method stub
}
}
查看图片的类 headportrail
package com.example.image;
import java.io.File;
import java.util.ArrayList;
import com.nostra13.universalimageloader.cache.disc.DiscCacheAware;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.assist.DiscCacheUtil;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
/*
* @author CrrayDraw
* @time 2015-6-1
* 查看图片
*/
public class HeadPortrait extends Activity implements OnPageChangeListener{
private ViewPager viewPager;
private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.aaa);
textView=(TextView) findViewById(R.id.textView);
viewPager=(ViewPager) findViewById(R.id.viewPager);
Intent intent = getIntent();
if (intent != null)
{
int currentPos=intent.getIntExtra("pos", 0);
MyAdapter adapter=new MyAdapter();
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(currentPos);
viewPager.setEnabled(false);
viewPager.setOnPageChangeListener(this);
textView.setText(currentPos+"/"+PhotoGlDetail.imageUrls.length);
}
}
class MyAdapter extends PagerAdapter{
@Override
public int getCount() {
// TODO Auto-generated method stub
return PhotoGlDetail.imageUrls.length;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
// TODO Auto-generated method stub
View view=(View) object;
container.removeView(view);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
// TODO Auto-generated method stub
Bitmap bitmap =null;
File file=DiscCacheUtil.findInCache(PhotoGlDetail.imageUrls[position], ImageLoader.getInstance().getDiscCache() );
if(file.exists()){
bitmap= BitmapFactory.decodeFile(file.getPath());
}
if(bitmap==null){
Log.i("values", "i:"+position);
bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.ic_empty);
}
Log.i("values", "iiiii:"+position);
View view=View.inflate(HeadPortrait.this, R.layout.img_frag, null);
ScaleImageView imageView=(ScaleImageView) view.findViewById(R.id.img);
imageView.setImageBitmap(bitmap);
container.addView(imageView);
return view;
}
@Override
public boolean isViewFromObject(View agr0, Object arg1) {
// TODO Auto-generated method stub
return agr0==arg1;
}
}
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
}
public void onPageSelected(int currentPos) {
// TODO Auto-generated method stub
textView.setText((currentPos+1)+"/"+PhotoGlDetail.imageUrls.length);
}
public String getpaths(String url){
String urlPath=url.substring(url.indexOf("/")+1);
return url;
}
}
网上流行的scaleimageview
package com.example.image;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.ImageView;
/**
* 来自网络：图片缩放控件（支持缩放、拖动双击旋转）<br>
*
* @author kymjs (https://github.com/kymjs)
*/
public class ScaleImageView extends ImageView {
public enum ImageState {
NONE, // 初始状
DRAG, // 拖动
ZOOM, // 缩放
ROTATE, // 旋转
ZOOM_OR_ROTATE // 缩放或旋
}
private ImageState mode = ImageState.NONE;
static final float MAX_SCALE = 2.5f;
private float imageW; // 图片宽度
private float imageH; // 图片高度
private float rotatedImageW;
private float rotatedImageH;
private float viewW;
private float viewH;
private final Matrix matrix = new Matrix();
private final Matrix savedMatrix = new Matrix();
private final PointF pA = new PointF();
private final PointF pB = new PointF();
private final PointF mid = new PointF();
private final PointF lastClickPos = new PointF();
private long lastClickTime = 0; // 上次点击时间（用于计算双击）
private double rotation = 0.0;
private float dist = 1f; // 两点间距
private boolean canRotate = true; // 是否启旋转图片功
private boolean canDoubleClick = true; // 是否启双击缩放功
public void setCanDoubleClick(boolean canDoubleClick) {
this.canDoubleClick = canDoubleClick;
}
public boolean canDoubleClick() {
return canDoubleClick;
}
public void setCanRotate(boolean canRotate) {
this.canRotate = canRotate;
}
public boolean canRotate() {
return canRotate;
}
public ScaleImageView(Context context) {
super(context);
initView();
}
public ScaleImageView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
public ScaleImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initView();
}
/**
* 初始化控
*/
private void initView() {
setScaleType(ImageView.ScaleType.MATRIX);
}
@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
setImageWidthHeight();
}
@Override
public void setImageDrawable(Drawable drawable) {
super.setImageDrawable(drawable);
setImageWidthHeight();
}
@Override
public void setImageResource(int resId) {
super.setImageResource(resId);
setImageWidthHeight();
}
private void setImageWidthHeight() {
Drawable d = getDrawable();
if (d == null) {
return;
}
imageW = rotatedImageW = d.getIntrinsicWidth();
imageH = rotatedImageH = d.getIntrinsicHeight();
initImage();
}
/**
* 图片大小改变时回
*/
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
viewW = w;
viewH = h;
if (oldw == 0) { // 如果图片还没有计算大
initImage();
} else {
fixScale(); // 固定大小
fixTranslation();
setImageMatrix(matrix);
}
}
/**
* 首次加载，初始化图片控件
*/
private void initImage() {
if (viewW <= 0 || viewH <= 0 || imageW <= 0 || imageH <= 0) {
return;
}
mode = ImageState.NONE;
matrix.setScale(0, 0);
fixScale();
fixTranslation();
setImageMatrix(matrix);
}
/**
* 设置matrix，记录当前图片大
*/
private void fixScale() {
float p[] = new float[9];
matrix.getValues(p);
float curScale = Math.abs(p[0]) + Math.abs(p[1]);
float minScale = Math.min(viewW / rotatedImageW, viewH / rotatedImageH);
if (curScale < minScale) {
if (curScale > 0) {
double scale = minScale / curScale;
p[0] = (float) (p[0] * scale);
p[1] = (float) (p[1] * scale);
p[3] = (float) (p[3] * scale);
p[4] = (float) (p[4] * scale);
matrix.setValues(p);
} else {
matrix.setScale(minScale, minScale);
}
}
}
/**
* 大缩放
*/
private float maxPostScale() {
float p[] = new float[9];
matrix.getValues(p);
float curScale = Math.abs(p[0]) + Math.abs(p[1]);
float minScale = Math.min(viewW / rotatedImageW, viewH / rotatedImageH);
float maxScale = Math.max(minScale, MAX_SCALE);
return maxScale / curScale;
}
/**
* 移动matrix
*/
private void fixTranslation() {
RectF rect = new RectF(0, 0, imageW, imageH);
matrix.mapRect(rect);
float height = rect.height();
float width = rect.width();
float deltaX = 0, deltaY = 0;
if (width < viewW) {
deltaX = (viewW - width) / 2 - rect.left;
} else if (rect.left > 0) {
deltaX = -rect.left;
} else if (rect.right < viewW) {
deltaX = viewW - rect.right;
}
if (height < viewH) {
deltaY = (viewH - height) / 2 - rect.top;
} else if (rect.top > 0) {
deltaY = -rect.top;
} else if (rect.bottom < viewH) {
deltaY = viewH - rect.bottom;
}
matrix.postTranslate(deltaX, deltaY);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
// 主点按下 ：记录当前matrix，以及初始化按下坐标、图片状
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
pA.set(event.getX(), event.getY());
pB.set(event.getX(), event.getY());
mode = ImageState.DRAG;
break;
// 副点按下 ：如果间距大10，记录此时matrix，以及两点的坐标、图片状
case MotionEvent.ACTION_POINTER_DOWN:
if (event.getActionIndex() > 1) // 超过两个点返
break;
dist = spacing(event.getX(0), event.getY(0), event.getX(1),
event.getY(1));
if (dist > 10f) { // 如果连续两点距离大于10，则判定为多点模
savedMatrix.set(matrix);
pA.set(event.getX(0), event.getY(0));
pB.set(event.getX(1), event.getY(1));
mid.set((event.getX(0) + event.getX(1)) / 2,
(event.getY(0) + event.getY(1)) / 2);
mode = ImageState.ZOOM_OR_ROTATE;
}
break;
// 主点或负点抬
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
if (mode == ImageState.DRAG) {
if (spacing(pA.x, pA.y, pB.x, pB.y) < 50) {
long now = System.currentTimeMillis();
if (now - lastClickTime < 500
&& spacing(pA.x, pA.y, lastClickPos.x,
lastClickPos.y) < 50) {
doubleClick(pA.x, pA.y);
now = 0;
}
lastClickPos.set(pA);
lastClickTime = now;
}
} else if (mode == ImageState.ROTATE) {
int level = (int) Math.floor((rotation + Math.PI / 4)
/ (Math.PI / 2));
if (level == 4)
level = 0;
matrix.set(savedMatrix);
matrix.postRotate(90 * level, mid.x, mid.y);
if (level == 1 || level == 3) {
float tmp = rotatedImageW;
rotatedImageW = rotatedImageH;
rotatedImageH = tmp;
fixScale();
}
fixTranslation();
setImageMatrix(matrix);
}
mode = ImageState.NONE;
break;
// 拖动
case MotionEvent.ACTION_MOVE:
if (mode == ImageState.ZOOM_OR_ROTATE) {
PointF pC = new PointF(event.getX(1) - event.getX(0) + pA.x,
event.getY(1) - event.getY(0) + pA.y);
double a = spacing(pB.x, pB.y, pC.x, pC.y);
double b = spacing(pA.x, pA.y, pC.x, pC.y);
double c = spacing(pA.x, pA.y, pB.x, pB.y);
if (a >= 10) {
double cosB = (a * a + c * c - b * b) / (2 * a * c);
double angleB = Math.acos(cosB);
double PID4 = Math.PI / 4;
if (angleB > PID4 && angleB < 3 * PID4) {
mode = ImageState.ROTATE;
rotation = 0;
} else {
mode = ImageState.ZOOM;
}
}
}
if (mode == ImageState.DRAG) {
matrix.set(savedMatrix);
pB.set(event.getX(), event.getY());
matrix.postTranslate(event.getX() - pA.x, event.getY() - pA.y);
fixTranslation();
setImageMatrix(matrix);
} else if (mode == ImageState.ZOOM) {
float newDist = spacing(event.getX(0), event.getY(0),
event.getX(1), event.getY(1));
if (newDist > 10f) {
matrix.set(savedMatrix);
float tScale = Math.min(newDist / dist, maxPostScale());
matrix.postScale(tScale, tScale, mid.x, mid.y);
fixScale();
fixTranslation();
setImageMatrix(matrix);
}
} else if (mode == ImageState.ROTATE) {
if (canRotate) {
PointF pC = new PointF(
event.getX(1) - event.getX(0) + pA.x, event.getY(1)
- event.getY(0) + pA.y);
double a = spacing(pB.x, pB.y, pC.x, pC.y);
double b = spacing(pA.x, pA.y, pC.x, pC.y);
double c = spacing(pA.x, pA.y, pB.x, pB.y);
if (b > 10) {
double cosA = (b * b + c * c - a * a) / (2 * b * c);
double angleA = Math.acos(cosA);
double ta = pB.y - pA.y;
double tb = pA.x - pB.x;
double tc = pB.x * pA.y - pA.x * pB.y;
double td = ta * pC.x + tb * pC.y + tc;
if (td > 0) {
angleA = 2 * Math.PI - angleA;
}
rotation = angleA;
matrix.set(savedMatrix);
matrix.postRotate((float) (rotation * 180 / Math.PI),
mid.x, mid.y);
setImageMatrix(matrix);
}
}
}
break;
}
return true;
}
/**
* 两点的距
*/
private float spacing(float x1, float y1, float x2, float y2) {
float x = x1 - x2;
float y = y1 - y2;
return (float) Math.sqrt(x * x + y * y);
}
/**
* 双击时调
*/
private void doubleClick(float x, float y) {
if (canDoubleClick) {
float p[] = new float[9];
matrix.getValues(p);
float curScale = Math.abs(p[0]) + Math.abs(p[1]);
float minScale = Math.min(viewW / rotatedImageW, viewH
/ rotatedImageH);
if (curScale <= minScale + 0.01) { // 放大
float toScale = Math.max(minScale, MAX_SCALE) / curScale;
matrix.postScale(toScale, toScale, x, y);
} else { // 缩小
float toScale = minScale / curScale;
matrix.postScale(toScale, toScale, x, y);
fixTranslation();
}
setImageMatrix(matrix);
}
}
} imageloader+scaleimageview+viewpager组合异步加载图片的图片浏览功能
原文地址：http://blog.csdn.net/u012303938/article/details/46328899
