使用Photoview实现图片左右滑动及缩放功能

我想，不管是做什么样的app。一般都会涉及到图片点击方法，和左右滑动的功能吧。今天我就把自己的实现拿来分享一下。图片的加载用到了picasso的图片加载工具。

第一步：注入依赖

compile 'com.squareup.picasso:picasso:2.5.2'
compile 'com.github.chrisbanes:PhotoView:1.3.0'

第二步，我们就来实现这个功能。多张图片左右滑动，这需要用到ViewPager这个类。

且看布局：

<uk.co.senab.photoview.sample.HackyViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/iv_photo"
android:layout_width="match_parent"
android:layout_height="match_parent"/>

这里用到了自定义的ViewPager

public class HackyViewPager extends ViewPager {

public HackyViewPager(Context context) {
super(context);
}

public HackyViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
try {
return super.onInterceptTouchEvent(ev);
} catch (IllegalArgumentException e) {
e.printStackTrace();
return false;
}
}
}

这个是点击之后跳转到大图的Activity,来显示大图。最重要也是很简单的一步：

package uk.co.senab.photoview.sample;

import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;

import com.squareup.picasso.Callback;
import com.squareup.picasso.Picasso;

import uk.co.senab.photoview.PhotoView;
import uk.co.senab.photoview.PhotoViewAttacher;

public class PicassoSampleActivity extends AppCompatActivity {

ViewPager mViewPager;
//String position;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_simple);
mViewPager = (HackyViewPager) findViewById(R.id.iv_photo);
setContentView(mViewPager);
mViewPager.setAdapter(new SamplePagerAdapter());
//position=getIntent().getStringExtra("position");

//设置默认的坐标，实际情况不要写死，只需点击哪张图片的position，并传过来接受就可以了，就默认显示点击图片的大图。
//mViewPager.setCurrentItem(Integer.parseInt(position));
mViewPager.setCurrentItem(2);
}

static class SamplePagerAdapter extends PagerAdapter {
//这里暂时写死了，实际情况中要从服务端获取图片地址结合，传过来
private static final String[] url = {"http://pbs.twimg.com/media/Bist9mvIYAAeAyQ.jpg", "http://d.hiphotos.bdimg.com/album/whcrop%3D657%2C370%3Bq%3D90/sign=2c994e578a82b9013df895711cfd9441/09fa513d269759eede0805bbb2fb43166d22df62.jpg",
"http://www.fwjia.com/d/file/2013-11-14/13631d143b7076dc3257b1e516a2a9a2.jpg", "http://img2.3lian.com/2014/f5/63/d/7.jpg"};

@Override
public int getCount() {
return url.length;
}

@Override
public View instantiateItem(ViewGroup container, int position) {
PhotoView photoView = new PhotoView(container.getContext());
final PhotoViewAttacher attacher = new PhotoViewAttacher(photoView);
Picasso.with(container.getContext())
.load(url[position])
.into(photoView, new Callback() {
@Override
public void onSuccess() {
attacher.update();
}

@Override
public void onError() {

}
});

container.addView(photoView, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);

return photoView;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}

@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}

}
}

有了这个工具我们很轻松就实现了图片点击放大，左右活动，缩放等功能。