本文实例介绍的android的gallery控件是个很不错的看图控件，可以大大减轻开发者对于看图功能的开发，并且效果也很美观。本文实例中的gallery的用法，主要实现用反射机制来动态读取资源中的图片。
该实例代码运行的效果图如下：
main.xml源码如下:
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<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<gallery android:id="@+id/gallery" android:layout_height="fill_parent" android:layout_width="fill_parent"></gallery>
</linearlayout>
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java程序源码如下：
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package com.testimageview;
import java.lang.reflect.field;
import java.util.arraylist;
import android.app.activity;
import android.content.context;
import android.graphics.bitmap;
import android.graphics.bitmapfactory;
import android.os.bundle;
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 android.widget.adapterview.onitemclicklistener;
public class testimageview extends activity {
private gallery mgallery;
@override
public void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.main);
mgallery = (gallery)findviewbyid(r.id.gallery);
try {
mgallery.setadapter(new imageadapter(this));
} catch (illegalargumentexception e) {
// todo auto-generated catch block
e.printstacktrace();
} catch (illegalaccessexception e) {
// todo auto-generated catch block
e.printstacktrace();
}
mgallery.setonitemclicklistener(new onitemclicklistener() {
public void onitemclick(adapterview parent, view v, int position, long id) {
testimageview.this.settitle(string.valueof(position));
}
});
}
/*
* class imageadapter is used to control gallery source and operation.
*/
private class imageadapter extends baseadapter{
private context mcontext;
private arraylist<integer> imglist=new arraylist<integer>();
private arraylist<object> imgsizes=new arraylist<object>();
public imageadapter(context c) throws illegalargumentexception, illegalaccessexception{
mcontext = c;
//用反射机制来获取资源中的图片id和尺寸
field[] fields = r.drawable.class.getdeclaredfields();
for (field field : fields)
{
if (!"icon".equals(field.getname()))//除了icon之外的图片
{
int index=field.getint(r.drawable.class);
//保存图片id
imglist.add(index);
//保存图片大小
int size[]=new int[2];
bitmap bmimg=bitmapfactory.decoderesource(getresources(),index);
size[0]=bmimg.getwidth();size[1]=bmimg.getheight();
imgsizes.add(size);
}
}
}
@override
public int getcount() {
// todo auto-generated method stub
return imglist.size();
}
@override
public object getitem(int position) {
// todo auto-generated method stub
return position;
}
@override
public long getitemid(int position) {
// todo auto-generated method stub
return position;
}
@override
public view getview(int position, view convertview, viewgroup parent) {
// todo auto-generated method stub
imageview i = new imageview (mcontext);
//从imglist取得图片id
i.setimageresource(imglist.get(position).intvalue());
i.setscaletype(imageview.scaletype.fit_xy);
//从imgsizes取得图片大小
int size[]= new int[2];
size=(int[]) imgsizes.get(position);
i.setlayoutparams(new gallery.layoutparams(size[0], size[1]));
return i;
}
};
}
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