photoview-----图片放大与缩小

最新推荐文章于 2018-10-24 14:39:23 发布

磊少1994

最新推荐文章于 2018-10-24 14:39:23 发布

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本文链接：https://blog.youkuaiyun.com/Lianglei1994/article/details/65629872

这篇博客介绍了如何在Android应用中实现图片点击后放大缩小的效果。通过引入PhotoView库，结合ViewPager和Picasso加载图片，实现了在GridView中点击图片跳转到新的Activity展示可缩放的图片。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1：导依赖

compile 'com.loopj.android:android-async-http:1.4.9'

compile 'com.squareup.picasso:picasso:2.5.1'

photoView 导jar包

compile files('libs/uk-co-senab-photoview.jar')

compile 'com.github.bumptech.glide:glide:3.5.2'

2：main_layout

点击item，跳过去activity的布局

<android.support.v4.view.ViewPager
        android:id="@+id/vp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />

适配器布局

最重要的布局

<uk.co.senab.photoview.PhotoView
        android:id="@+id/pv"
        android:layout_width="wrap_content"
        android:scaleType="centerCrop"
        android:layout_height="wrap_content"
        />

3：代码

public class ImageActivity extends AppCompatActivity {
    private ViewPager vp;
    private List<User.DataInfo> list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_image);
        vp= (ViewPager) findViewById(R.id.vp);

        Intent intent = getIntent();
        User user = (User) intent.getSerializableExtra("user");
        list = user.data;
        int position = intent.getIntExtra("position", 0);

        vp.setAdapter(new PagerAdapter() {
            @Override
            public int getCount() {
                return list.size();
            }

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

            @Override
            public Object instantiateItem(ViewGroup container, int position) {
                View view=View.inflate(ImageActivity.this,R.layout.item,null);
                PhotoView pv= (PhotoView) view.findViewById(R.id.pv);
                String image_url = list.get(position).image_url;
                Picasso.with(ImageActivity.this).load(image_url).into(pv);
                container.addView(view);
                return view;
            }

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

    }
}

MAinActivity

public class MainActivity extends AppCompatActivity {
    private GridView gv;
    private List<User.DataInfo> list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        gv= (GridView) findViewById(R.id.gv);
        //获取数据
        getServerData();
    }

    private void getServerData() {
        String url="http://mock.eoapi.cn/success/aDpzG1ZiKPbEI6JdXjqasb958Q1rBg9j";
        AsyncHttpClient client=new AsyncHttpClient();
        client.get(MainActivity.this, url, new TextHttpResponseHandler() {
            @Override
            public void onFailure(int statusCode, Header[] headers, String responseString, Throwable throwable) {

            }

            @Override
            public void onSuccess(int statusCode, Header[] headers, String responseString) {

                Gson gson=new Gson();
                final User user = gson.fromJson(responseString, User.class);
                list = user.data;
                gv.setAdapter(new MyAdapter());
                gv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                    @Override
                    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                        Intent it=new Intent(MainActivity.this,ImageActivity.class);
                        Bundle bundle=new Bundle();
                        bundle.putSerializable("user",user);
                        it.putExtras(bundle);
                        it.putExtra("position",position);
                        startActivity(it);
                    }
                });
            }
        });
    }
    class MyAdapter extends BaseAdapter{

        @Override
        public int getCount() {
            return list.size();
        }

        @Override
        public Object getItem(int position) {
            return position;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView image=new ImageView(MainActivity.this);
            Picasso.with(MainActivity.this).load(list.get(position).image_url).into(image);
            return image;
        }
    }
}