using Android.App;using Android.OS;using Android.Widget;namespace ImageDemo{  [Activity(Label = "@string/ApplicationName", MainLauncher = true, Icon = "@drawable/icon")]  public class MainActivity : Activity  {    private Gallery _gallery;    private ImageView _selectedImg;    private readonly int[] _imageIds = {      Resource.Drawable.test1,      Resource.Drawable.test2,      Resource.Drawable.test3,      Resource.Drawable.test4,      Resource.Drawable.test5,      Resource.Drawable.test6,      Resource.Drawable.test7,      Resource.Drawable.test8  };    protected override void OnCreate(Bundle bundle)    {      base.OnCreate(bundle);      SetContentView(Resource.Layout.Main);      _gallery = FindViewById<Gallery>(Resource.Id.gallery);      _selectedImg = FindViewById<ImageView>(Resource.Id.currentImg);      _gallery.Adapter = new ImageAdapter(this, _imageIds);      _gallery.ItemSelected += Gallery_ItemSelected;    }    private void Gallery_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e)    {      _selectedImg.SetImageResource(_imageIds[e.Position]);    }  }public class ImageAdapter : BaseAdapter  {    private readonly Context _context;    private readonly int[] _imageIds;    public ImageAdapter(Context context,int[]imageIds)    {      _context = context;      _imageIds = imageIds;    }    public override Object GetItem(int position)    {      return null;    }    public override long GetItemId(int position)    {      return 0;    }    public override int Count    {      get { return _imageIds.Length; }    }    public override View GetView(int position, View convertView, ViewGroup parent)    {      var image = new ImageView(_context);      image.SetImageResource(_imageIds[position]);      image.LayoutParameters = new Gallery.LayoutParams(150, 100);      image.SetScaleType(ImageView.ScaleType.FitXy);      return image;    }  }}

package com.example.halower.gallerydemo;import android.content.Context;import android.os.Bundle;import android.support.v7.app.ActionBarActivity;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.BaseAdapter;import android.widget.Gallery;import android.widget.ImageView;import static android.widget.Gallery.LayoutParams;public class MainActivity extends ActionBarActivity {  private int[] imageIds = {      R.drawable.test1,      R.drawable.test2,      R.drawable.test3,      R.drawable.test4,      R.drawable.test5,      R.drawable.test6,      R.drawable.test7,      R.drawable.test8  };  Gallery gallery;  ImageView currentView;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    gallery=(Gallery) findViewById(R.id.gallery);    ImageAdapter adapter=new ImageAdapter(this,imageIds);    currentView = (ImageView)findViewById(R.id.currentImg);    gallery.setAdapter(adapter);    gallery.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener(){      @Override      public void onItemSelected(AdapterView<?> parent, View view, int position,long id) {        currentView.setImageResource(imageIds[position]);      }      @Override      public void onNothingSelected(AdapterView<?> parent) {      }    });  }}class ImageAdapter extends BaseAdapter{  Context _context;  int[] imageIds;  public ImageAdapter(Context context,int[] imageIds){    _context=context;    this.imageIds=imageIds;  }  @Override  public int getCount() {    return imageIds.length;  }  @Override  public Object getItem(int position) {    return null;  }  @Override  public long getItemId(int position) {    return 0;  }  @Override  public View getView(int position, View convertView, ViewGroup parent) {    ImageView imageView=new ImageView(_context);    imageView.setImageResource(imageIds[position]);    imageView.setScaleType(ImageView.ScaleType.FIT_XY);    imageView.setLayoutParams(new LayoutParams(70,100));    return imageView;  }}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"  android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"  android:paddingRight="@dimen/activity_horizontal_margin"  android:paddingTop="@dimen/activity_vertical_margin"  android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">  <ImageView    android:layout_width="320dp"    android:layout_height="320dp"    android:id="@+id/currentImg"    android:layout_centerHorizontal="true" />  <Gallery    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:unselectedAlpha="0.6"    android:spacing="2pt"    android:layout_below="@+id/currentImg"    android:id="@+id/gallery" /></RelativeLayout>