ViewPage选择变大效果

package com.itheima.galleryview;

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

import com.itheima.galleryview.view.ViewPagerTransform;

public class ViewPagerAct extends AppCompatActivity {

private ViewPagerTransform viewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_viewpager);

    viewPager = (ViewPagerTransform) findViewById(R.id.viewpager);

    // 设置页面间距
    viewPager.setPageMargin(15);
    viewPager.setAdapter(new PagerAdapter() {
        @Override
        public int getCount() {
            return 10;
        }

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

// @Override
// public float getPageWidth(int position) {
// return 0.8f;
// }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            View view = View.inflate(container.getContext(),R.layout.widget_gallery_view, null);

// view.setLayoutParams(getPageLayoutParams());
ImageView iv = (ImageView) view.findViewById(R.id.headRIV);
iv.setImageResource(position % 2 == 0 ? R.mipmap.a1 : R.mipmap.head);
container.addView(view);
return view;
}

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

// @Override
// public float getPageWidth(int position) {
// return 0.5f;
// }
});
}

private ViewPager.LayoutParams getPageLayoutParams() {
    ViewPager.LayoutParams layoutParams = new ViewPager.LayoutParams();
    layoutParams.width = (int) (viewPager.getMeasuredWidth() * 0.85);
    layoutParams.height = viewPager.getMeasuredHeight();
    return layoutParams;
}

}