Android中Gallery和ImageSwitcher的使用

效果如下：

布局文件activity_main.xml如下：

<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" >        <ImageSwitcher          android:id="@+id/imageSwitcher"          android:layout_width="wrap_content"          android:layout_height="wrap_content"          android:layout_weight="2"          android:paddingTop="30px" >      </ImageSwitcher>        <Gallery          android:id="@+id/gallery1"          android:layout_width="match_parent"          android:layout_height="wrap_content"          android:layout_weight="1"          android:spacing="5px"          android:unselectedAlpha="0.6" />    </RelativeLayout>

MainActivity.java代码如下：

import android.app.ActionBar.LayoutParams;  import android.app.Activity;  import android.os.Bundle;  import android.view.View;  import android.view.animation.AnimationUtils;  import android.widget.AdapterView;  import android.widget.AdapterView.OnItemSelectedListener;  import android.widget.Gallery;  import android.widget.ImageSwitcher;  import android.widget.ImageView;  import android.widget.ViewSwitcher.ViewFactory;    public class MainActivity extends Activity {        private int imageId[] = new int[] { R.drawable.a, R.drawable.b,              R.drawable.c, R.drawable.d, R.drawable.e, R.drawable.f,              R.drawable.g, R.drawable.h, R.drawable.i, R.drawable.j,              R.drawable.k };        private ImageSwitcher imageSwitcher;      private Gallery gallery;        @Override      protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.activity_main);          imageSwitcher = (ImageSwitcher) this.findViewById(R.id.imageSwitcher);          gallery = (Gallery) this.findViewById(R.id.gallery1);            // 设置动画效果          imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,                  android.R.anim.fade_in));          imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,                  android.R.anim.fade_out));            imageSwitcher.setFactory(new ViewFactory() {                @Override              public View makeView() {                  ImageView imageView = new ImageView(MainActivity.this);                  imageView.setScaleType(ImageView.ScaleType.FIT_CENTER); // 设置保持纵横比居中                  imageView.setLayoutParams(new ImageSwitcher.LayoutParams(                          LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));                    return imageView;              }          });            GalleryAdapter adapter = new GalleryAdapter(MainActivity.this,imageId);          gallery.setAdapter(adapter);          gallery.setSelection(imageId.length / 2);          gallery.setOnItemSelectedListener(new OnItemSelectedListener() {                @Override              public void onItemSelected(AdapterView<?> parent, View view,int position, long id) {                  imageSwitcher.setImageResource(imageId[position]);              }                @Override              public void onNothingSelected(AdapterView<?> arg0) {                }          });      }  }

其中需要的一个适配器：

import android.content.Context;  import android.content.res.TypedArray;  import android.view.View;  import android.view.ViewGroup;  import android.widget.BaseAdapter;  import android.widget.Gallery;  import android.widget.ImageView;    public class GalleryAdapter extends BaseAdapter {        private int[] imageId;        private Context mContext;        /**       * 穿入上下文和图片资源数组       * @param mContext       * @param imageId       */      public GalleryAdapter(Context mContext, int[] imageId) {          this.mContext = mContext;          this.imageId = imageId;      }        @Override      public int getCount() {          return imageId.length;      }        @Override      public Object getItem(int position) {          return imageId[position];      }        @Override      public long getItemId(int position) {          return position;      }        @Override      public View getView(int position, View convertView, ViewGroup parent) {          ImageView imageView1;          if (convertView == null) {              imageView1 = new ImageView(mContext);              imageView1.setScaleType(ImageView.ScaleType.FIT_XY);              imageView1.setLayoutParams(new Gallery.LayoutParams(180, 135));              TypedArray typedArray = mContext                      .obtainStyledAttributes(R.styleable.Gallery);              imageView1.setBackgroundResource(typedArray.getResourceId(                      R.styleable.Gallery_android_galleryItemBackground, 0));              imageView1.setPadding(5, 0, 5, 0); // 设置ImageView的内边距          } else {              imageView1 = (ImageView) convertView;          }          imageView1.setImageResource(imageId[position]); // 为ImageView设置要显示的图片          return imageView1; // 返回ImageView      }    }