Android图片转换器代码分享

mainactivity.java

package com.zhang.showphoto;
 
import android.app.actionbar.layoutparams;
import android.app.activity;
import android.os.bundle;
import android.view.view;
import android.view.view.onclicklistener;
import android.view.animation.animationutils;
import android.widget.button;
import android.widget.imageswitcher;
import android.widget.imageview;
import android.widget.viewswitcher.viewfactory;
 
public class mainactivity extends activity {
   
  private int[] imagid=new int[]{
      r.drawable.img01,r.drawable.img02,r.drawable.img03,r.drawable.img04,
      r.drawable.img05,r.drawable.img06,r.drawable.img07,r.drawable.img08,
      r.drawable.img09,r.drawable.img10
    };
  private int index=0;
  private imageswitcher imageswitcher;
  private button up,down;
   
 
  @override
  protected void oncreate(bundle savedinstancestate) {
   
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.main);
     
    up=(button) findviewbyid(r.id.bt1);
    down=(button) findviewbyid(r.id.bt2);
     
   
    imageswitcher=(imageswitcher) findviewbyid(r.id.imagsw1);
    imageswitcher.setinanimation(animationutils.loadanimation(this, android.r.anim.fade_in));
    imageswitcher.setoutanimation(animationutils.loadanimation(this, android.r.anim.fade_out));
    imageswitcher.setfactory(new viewfactory() {
       
     
      public view makeview() {
        imageview imageview = new imageview(mainactivity.this);
        imageview.setscaletype(imageview.scaletype.fit_center);
        imageview.setlayoutparams(new imageswitcher.layoutparams(
            layoutparams.wrap_content,layoutparams.wrap_content
            ));
        return imageview;
      }
    });
     
    imageswitcher.setimageresource(imagid[index]);
     
    up.setonclicklistener(new onclicklistener() {
       
      @override
      public void onclick(view v) {
        if(index>0){
          index--;
        }else{
          index=imagid.length-1;
        }
        imageswitcher.setimageresource(imagid[index]);
      }
    });
     
    down.setonclicklistener(new onclicklistener() {
       
      @override
      public void onclick(view v) {
        if(index<imagid.length-1){
          index++;
        }else{
          index=0;
        }
        imageswitcher.setimageresource(imagid[index]);
      }
    });
   
  }
   
 
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:background="@drawable/bg1"
  android:id="@+id/llayout"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:gravity="center"
  android:orientation="horizontal" >
 
  <button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="上一张"
    android:id="@+id/bt1"
    />
  <imageswitcher
     android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/imagsw1"
    android:layout_gravity="center"
    />
   <button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="下一张"
    android:id="@+id/bt2"
    />
 
</linearlayout>

再来看一段代码

    // 获取图片的宽高
    bitmapfactory.options opt = new bitmapfactory.options();
    opt.injustdecodebounds = true;
    try{
      bitmapin = bitmapfactory.decodefile(puzzle.user.custom_image[customimage], opt);
    }catch(exception e){
      if(d) log.d(tag,"error");
      return;
    }
    int in_w=opt.outwidth,in_h=opt.outheight;
     
    // 获取imageview的尺寸 注意imageview的宽高比要与原图相同 否则需要另行计算
    full_w = imageview.getwidth()
    full_h = getheight()
 
    // 计算缩放比例 带有四舍五入
    int size_rate=(in_w*in_h*10)/(full_w*full_h);
    if(size_rate>10){
      size_rate+=5; 
      size_rate/=10;
    }else{
      size_rate=1;
    }
 
    // 重新设置opt 读取图片文件
    opt.insamplesize=size_rate;
    opt.injustdecodebounds = false;
    opt.inscaled = false;
 
    opt.outwidth=full_w;
    opt.outheight=full_h;
    bitmapin = bitmapfactory.decodefile(puzzle.user.custom_image[customimage], opt);}