Android 实现图片的自动缩放，适应分辨率不同的手机

以下代码可实现Android图片按照不同屏幕手机的大小 比例缩放。

1、定义 bitmap

public Bitmap viewBg;// 背景图

2、给他图片资源

viewBg = BitmapFactory.decodeResource(res, R.drawable.shuaibao_bg);

3、就是正事了，自己看吧

canvas.save();
Matrix matrix=new Matrix();
int width = viewBg.getWidth();//获取资源位图的宽
int height = viewBg.getHeight();//获取资源位图的高
float w = scalX/viewBg.getWidth();
float h = scalY/viewBg.getHeight();
matrix.postScale(w, h);//获取缩放比例
Bitmap dstbmp = Bitmap.createBitmap(viewBg,0,0,
width,height,matrix,true);//根据缩放比例获取新的位图
canvas.drawBitmap(dstbmp,0,0, mPaint); //在屏幕上画出位图
canvas.restore();

下面是最全面的代码：

import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import cn.com.ldci.madc.firecrackers.R;
import cn.com.ldci.madc.firecrackers.ui.shuaibao.ShuaiBaoActivity;

public class ShuaiBaoView extends SurfaceView implements SurfaceHolder.Callback{

 ShuaiBaoActivity main = new ShuaiBaoActivity();

 //状态
 public final static int START = 0;//摔炮开始运动
 public final static int PAUSE =1;//软件暂停
 public final static int HIT =2;//定义摔炮撞墙是的状态
 //监听软件状态
 public  int state = PAUSE;
 //定义图片
 public Bitmap imgBao;
 public Bitmap imgBaoend;
 public Bitmap imgBaobg;
 Bitmap dstbmp ;
// private Animation mAnimationTranslate;//定义平移的动画
 //定义摔炮位置
 public int x;
 public int y;
 int initX ;
 public int initY ;
 private float scalX;
 private float scalY;
 //定义摔炮运行速度
 public int speed = 15;
 //定义线程的运行参数
 public boolean isStop = true;
 SurfaceHolder holder;

 Intent intent;
 Context context;

 public ShuaiBaoView(Context context,int x,int y) {
  super(context);
  // TODO Auto-generated constructor stub

  this.context = context;
  initY = y-30;//初始化摔炮y轴初始坐标
  this.x = x/2-5;;//初始化摔炮x轴坐标
  this.y = initY;//初始化摔炮Y周卓表
  scalX = x;//保存屏幕宽
  scalY = y;//保存屏幕高
  holder = getHolder();//获取holder
  holder.addCallback(this);
  Resources res = context.getResources();
  imgBao = BitmapFactory.decodeResource(res,R.drawable.shuaibao_bao);
  imgBaoend = BitmapFactory.decodeResource(res,R.drawable.shuaipao_baoend);
  imgBaobg = BitmapFactory.decodeResource(res,R.drawable.shuaibao_bg);
  Matrix matrix=new Matrix();
  matrix.postScale(scalX/imgBaobg.getWidth(),
    scalY/imgBaobg.getHeight());//获取缩放比例
  dstbmp = Bitmap.createBitmap(imgBaobg,0,0,imgBaobg.getWidth(),
    imgBaobg.getHeight(),matrix,true);//按缩放比例生成适应屏幕的新的bitmap；
  intent = new Intent("com.soundmanagerbao.android.music");
  setFocusable(true);
 }
 public void onDraw(Canvas canvas){
  super.onDraw(canvas);
  //绘制图片
  canvas = holder.lockCanvas(null);//获取画布
  Paint mPaint = new Paint();//获取画笔
  //画自适应背景
  canvas.save();
  canvas.drawBitmap(dstbmp, 0, 0, mPaint); //画出图片
  canvas.restore();
  switch(state){
  case PAUSE:{//暂停

   canvas.save();
   canvas.drawBitmap(imgBao, x, initY,mPaint);
   canvas.restore();
  }
  break;
  case START://开始
  {
   canvas.save();
   canvas.drawBitmap(imgBao, x, y,mPaint);
   canvas.restore();
   y-=speed;
   if(y<=120){
    state = HIT;
   }
  }
  break;
  case HIT:{//撞击
   canvas.save();
   canvas.drawBitmap(imgBaoend, x, 115,mPaint);
   canvas.drawBitmap(imgBaoend, x, 115,mPaint);
   canvas.restore();
   context.startService(intent);
   state = PAUSE;
  }
  break;
  }
  holder.unlockCanvasAndPost(canvas);
 }
 class MyThread implements Runnable{//画图，刷新

  @Override
  public void run() {
   // TODO Auto-generated method stub
   while(isStop){
    Canvas canvas1 = null;
    onDraw(canvas1);
   }
  }

 }
 @Override
 public void surfaceChanged(SurfaceHolder holder, int format, int width,
   int height) {
  // TODO Auto-generated method stub

 }
 @Override
 public void surfaceCreated(SurfaceHolder holder) {
  // TODO Auto-generated method stub
  isStop = true;
  new Thread(new MyThread()).start();//开始线程
 }
 @Override
 public void surfaceDestroyed(SurfaceHolder holder) {
  // TODO Auto-generated method stub
  isStop = false;//返回时关闭线程
 }

}