在我们制作一个图片浏览器的时候，Android ImageSwitcher与Gallery组合使用是一个比较简便的方法，现在我们来看一下他们的基本用法。
1、配置布局文件 main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageSwitcher
android:id="@+id/imageSwitcher"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
/>
<Gallery
android:id="@+id/gallery"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:spacing="8dp"
android:layout_alignParentBottom="true"
/>
</RelativeLayout>
2、程序主要代码 MainActivity.java
package com.yin.picture_view;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;
public class MainActivity extends Activity {
// 显示图片的资源
private static int[] images = { R.drawable.s0, R.drawable.s1,
R.drawable.s2, R.drawable.s3, R.drawable.s4, R.drawable.s5,
R.drawable.s6, R.drawable.s7, R.drawable.s8, R.drawable.s9 };
Gallery gallery;
ImageSwitcher is;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gallery = (Gallery) findViewById(R.id.gallery);
is = (ImageSwitcher) findViewById(R.id.imageSwitcher);
gallery.setAdapter(new ImageAdapter(this));
// 让选定的图片在中心显示
gallery.setSelection(images.length / 2);
// 为Gallery绑定监听器；
gallery.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<!--?--> parent, View view,
int position, long id) {
// 当在Gallery中选定一张图片是 ImageSwitcher同步显示同一张
// position%images.length 为了让图片循环显示
is.setImageResource(images[position % images.length]);
}
public void onNothingSelected(AdapterView<!--?--> parent) {
}
});
is.setFactory(new ImageFactory(this));
}
private class ImageAdapter extends BaseAdapter {
private Context context;
public ImageAdapter(Context context) {
this.context = context;
}
// 可以return images.lenght(),在这里返回Integer.MAX_VALUE
// 是为了使图片循环显示
public int getCount() {
return Integer.MAX_VALUE;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView iv = new ImageView(context);
iv.setImageResource(images[position % images.length]);
iv.setLayoutParams(new Gallery.LayoutParams(90, 90));
iv.setAdjustViewBounds(true);
return iv;
}
}
private class ImageFactory implements ViewFactory {
private Context context;
public ImageFactory(Context context) {
this.context = context;
}
public View makeView() {
ImageView iv = new ImageView(context);
iv.setLayoutParams(new ImageSwitcher.LayoutParams(200, 200));
return iv;
}
}
}
