Android基础篇之ImageSwitcher与Gallery

Android基础篇之ImageSwitcher与Gallery

2011-05-19 16:16:15

自己制作一个图片浏览器的时候ImageSwitcher与Gallery组合使用是一个比较简遍的方法，现在我们蓝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; } } }