<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="fill_parent"  android:layout_height="fill_parent"  android:id="@+id/frameLayout1"  android:orientation="vertical"  >   </FrameLayout> 

package com.example.test;  import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.BitmapShader; import android.graphics.Canvas; import android.graphics.Matrix; import android.graphics.Shader.TileMode; import android.graphics.drawable.ShapeDrawable; import android.graphics.drawable.shapes.OvalShape; import android.os.Bundle; import android.view.MotionEvent; import android.view.View; import android.widget.FrameLayout;  public class MainActivity extends Activity {    @Override  public void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.main);     //獲取布局文件中添加的幀布局管理器   FrameLayout fl=(FrameLayout)findViewById(R.id.frameLayout1);   //將自定義的MyView視圖添加到幀布局   fl.addView(new MyView(this));  }    public class MyView extends View{   private Bitmap bitmap;//源圖像，也就是背景圖像   private ShapeDrawable drawable;   private final int RADIUS=57;//放大鏡的半徑   private final int FACTOR=2;//放大倍數(shù)   private Matrix matrix=new Matrix();   private Bitmap bitmap_magnifiter;//放大鏡位圖   private int m_left=0;//放大鏡的左邊距   private int m_top=0;//放大鏡的頂邊距      public MyView(Context context) {    super(context);        //獲取要顯示的源圖像    Bitmap bitmap_source=BitmapFactory.decodeResource(getResources(), R.drawable.backgroud);    bitmap=bitmap_source;    BitmapShader shader=new BitmapShader(Bitmap.createScaledBitmap(      bitmap_source, bitmap_source.getWidth()*FACTOR,      bitmap_source.getHeight()*FACTOR, true),TileMode.CLAMP,      TileMode.CLAMP);//創(chuàng)建BitmapShader對(duì)象    /* 注：Bitmap.createScaledBitmap() 方 法根據(jù)給定的 Bitmap 創(chuàng)建 一個(gè)新的，縮放后的 Bitmap。     * Shader.TileMode類(lèi)型的參數(shù)包括CLAMP、MIRROR和REPEAT3個(gè)可選值，其中，CLAMP為使用     * 邊界顏色來(lái)填充剩余的空間；MIRROR為采用鏡像方式；REPEAT為采用重復(fù)方式*/        //圓形的drawable    drawable=new ShapeDrawable(new OvalShape());    drawable.getPaint().setShader(shader);    drawable.setBounds(0, 0, RADIUS*2, RADIUS*2);//設(shè)置圓的外切矩形    bitmap_magnifiter=BitmapFactory.decodeResource(getResources(),      R.drawable.magnifiter);//獲取放大鏡圖像    m_left=RADIUS-bitmap_magnifiter.getWidth()/2;//計(jì)算放大鏡默認(rèn)的左邊距    m_top=RADIUS-bitmap_magnifiter.getHeight()/2;//計(jì)算放大鏡默認(rèn)的右邊距   }     @Override   protected void onDraw(Canvas canvas) {    canvas.drawBitmap(bitmap, 0,0, null);//繪制背景圖像    canvas.drawBitmap(bitmap_magnifiter, m_left, m_top,null);//繪制放大鏡圖像    drawable.draw(canvas);//繪制放大后的圖像    super.onDraw(canvas);   }     //重寫(xiě)onTouchEvent方法實(shí)現(xiàn)當(dāng)用戶(hù)觸摸屏幕時(shí)，放大觸摸點(diǎn)附近的圖像   @Override   public boolean onTouchEvent(MotionEvent event) {    final int x=(int)event.getX();    final int y=(int)event.getY();    //平移到繪制shader的起始位置    matrix.setTranslate(RADIUS-x*FACTOR, RADIUS-y*FACTOR);    drawable.getPaint().getShader().setLocalMatrix(matrix);    drawable.setBounds(x-RADIUS,y-RADIUS,x+RADIUS,y+RADIUS);//設(shè)置圓的外切矩形    m_left=x-bitmap_magnifiter.getWidth()/2;//計(jì)算放大鏡的左邊距    m_top=y-bitmap_magnifiter.getHeight()/2;//計(jì)算放大鏡的右邊距    invalidate();//重繪畫(huà)布        return true;   }        } }