Gallery的应用以及点击显示点击的是第几张图片

MainActivity

package com.example.gallerylx;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Gallery;
import android.widget.Toast;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);

Gallery g=(Gallery) this.findViewById(R.id.gallery1);

//添加ImageAdapter给Galley
g.setAdapter(new ImageAdapter(this));

//设置Gallery背景
g.setBackgroundResource(R.drawable.aa);

//设置Gallery事件监听
g.setOnItemClickListener(new OnItemClickListener() {

@Override
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
Toast.makeText(MainActivity.this, "你选择了"+position+"号图片", Toast.LENGTH_SHORT).show();
}

});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}
ImageAdapter

package com.example.gallerylx;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;

public class ImageAdapter extends BaseAdapter {

// 定义Context
private Context context;
private int[] images = { R.drawable.a, R.drawable.b, R.drawable.c,
R.drawable.d, R.drawable.e,R.drawable.f,R.drawable.g,R.drawable.h };

public ImageAdapter(Context context) {
this.context = context;
}

// 获取图片个数
public int getCount() {

return images.length;
}

@Override
// 获取图片在库中的位置
public Object getItem(int position) {
return position;
}

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView view = new ImageView(context);

// 给ImageView设置资源
view.setImageResource(images[position]);

// 设置布局图片以120*120显示
view.setLayoutParams(new Gallery.LayoutParams(120, 120));

// 设置显示比例类型
view.setScaleType(ImageView.ScaleType.FIT_CENTER);

return view;
}

}

Activity_main.xml

<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<Gallery
android:id="@+id/gallery1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="18dp"
/>

</RelativeLayout>