布局：

　　

 

代码：

 

package me.chunsheng.hongbao.activities;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.LinearLayout;import java.io.IOException;import java.io.InputStream;import me.chunsheng.hongbao.R;public class GallaryActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_gallary);        final ImageView diplayImage = (ImageView) findViewById(R.id.displayImage);        final LinearLayout myGallery = (LinearLayout) findViewById(R.id.mygallery);        try {            String galleryDirectoryName = "gallery";            String[] listImages = new String[3];            for (int i = 0; i < 4; i++) {                //InputStream is = getAssets().open(galleryDirectoryName + "/" + imageName);                //final Bitmap bitmap = BitmapFactory.decodeStream(is);                ImageView imageView = new ImageView(getApplicationContext());                imageView.setLayoutParams(new ViewGroup.LayoutParams(700, 700));                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);                imageView.setImageResource(R.mipmap.mayun);                imageView.setOnClickListener(new View.OnClickListener() {                    @Override                    public void onClick(View view) {                        diplayImage.setImageResource(R.mipmap.bg_action_bar);                    }                });                myGallery.addView(imageView);            }        } catch (Exception e) {        }    }}