微信放大效果，簡易版

別問，拷貝上就好使，傻瓜操作！！！

傳過來的數據：

    JSONArray jsonArray = new JSONArray();
    jsonArray.put("https://vip.wenes.cn/khmember/images/wenes/logo_new.png");
    jsonArray.put("https://vip.wenes.cn/khmember/images/wenes/logo_new.png");
    jsonArray.put("https://vip.wenes.cn/khmember/images/wenes/logo_new.png");
    startActivity(new Intent(this, ShowImageActivity.class)
            //圖片路徑
           .putExtra("json", jsonArray.toString())
           //圖片位置 
           .putExtra("index", 1)
    );
}

首先是ShowImageViewActivity：

public class ShowImageActivity extends AppCompatActivity {
    JSONArray jsonArray = null;
    private int index;
    private ViewPager viewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_show_image);
//        setWindowStatusBarColor(this, R.color.black);
        getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
        viewPager = (ViewPager) findViewById(R.id.viewPager);
        Intent intent = getIntent();
        String json = intent.getStringExtra("json");
        index = intent.getIntExtra("index", -1);

        ArrayList<String> arrayList = new ArrayList<>();
        if (!TextUtils.isEmpty(json)) {
            try {
                jsonArray  = new JSONArray(json);
                if(index != -1){
                    if (jsonArray != null) {
                        for (int i = 0; i < jsonArray.length(); i++) {
                            String string = jsonArray.getString(i);
                            arrayList.add(string);
                        }
                    }
                }

            } catch (JSONException e) {
                e.printStackTrace();
            }
        }

        PagerAdapter pagerAdapter = new PagerAdapter(arrayList);
        viewPager.setAdapter(pagerAdapter);
        if (index != -1) {
            viewPager.setCurrentItem(index);
        }
    }

    public static void setWindowStatusBarColor(Activity activity, int colorResId) {
        try {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                Window window = activity.getWindow();
                window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
                window.setStatusBarColor(activity.getResources().getColor(colorResId));


            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    class PagerAdapter extends android.support.v4.view.PagerAdapter {

        public ArrayList<String> arrayList;

        public PagerAdapter(ArrayList<String> arrayList) {
            this.arrayList = arrayList;
        }

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

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

        @NonNull
        @Override
        public Object instantiateItem(@NonNull ViewGroup container, int position) {
            View inflate = LayoutInflater.from(ShowImageActivity.this).inflate(R.layout.show_image_viewpager_item, null);
            PhotoView viewById = inflate.findViewById(R.id.imageView_item);
            Glide.with(ShowImageActivity.this).load(arrayList.get(position)).into(viewById);
            container.addView(inflate);
            return inflate;
        }

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

    float x1;
    float x2;
    float y1;
    float y2;
    boolean isMove = false;

    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                //當手指按下的時候
                x1 = event.getX();
                y1 = event.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                //當手指移動的時候
                x2 = event.getX();
                y2 = event.getY();
                if ((y1 - y2 > 50) || (y2 - y1 > 50) || (x1 - x2 > 50) || (x2 - x1 > 50)) {
                    isMove = true;
                }

                break;
            case MotionEvent.ACTION_UP:
                //當手指擡起的時候
                if (!isMove) {
                    finish();
                }
                isMove = false;
                break;
        }
        return super.dispatchTouchEvent(event);

    }
}

其次是xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".ShowImageActivity">

    <com.rxjy.myapplication.MyViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#000"
        ></com.rxjy.myapplication.MyViewPager>

</LinearLayout>

然後自定義一個ViewPager：

public class MyViewPager extends ViewPager {
    public MyViewPager(@NonNull Context context) {
        super(context);
    }

    public MyViewPager(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        try {
            return super.onTouchEvent(ev);
        } catch (IllegalArgumentException ex) {
            ex.printStackTrace();
        }
        return false;
    }

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

對了，還有ViewPagerAdapter的xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <uk.co.senab.photoview.PhotoView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imageView_item"
        android:src="@mipmap/ic_launcher"
        />

</RelativeLayout>

最後PhotoView的依賴：

implementation 'com.github.chrisbanes.photoview:library:1.2.4'

項目的grade中的AllProject下

maven { url "https://jitpack.io" }

對了還需要一個V4包和Glide：

implementation 'com.android.support:support-v4:28.0.0'

implementation 'com.github.bumptech.glide:glide:3.7.0'