Android基于google Zxing实现各类二维码扫描效果

随着微信的到来，二维码越来越火爆，随处能看到二维码，比如商城里面，肯德基，餐厅等等，对于二维码扫描我们使用的是google的开源框架zxing,我们可以去http://code.google.com/p/zxing/下载源码和jar包，之前我项目中的二维码扫描功能只实现了扫描功能，其ui真的是其丑无比，一个好的应用软件，其ui界面也要被大众所接纳，不然人家就不会用你的软件啦，所以说应用软件功能和界面一样都很重要，例如微信，相信微信ui被很多应用软件所模仿，我也仿照微信扫描二维码效果进行模仿，虽然没有微信做的那么精致，但是效果还是可以的，所以将自己修改ui的代码和扫描二维码的代码分享给大家，一是自己以后项目遇到同样的功能直接拷贝来用，二是给还没有加入二维码功能的人一个参考，站在巨人的肩膀上,哈哈，我之前也是站在巨人的肩膀上加上此功能，接下来跟着我一步一步来实现此项功能，里面去除了很多不必要的文件

我们先看下项目的结构

• 如果你项目也想加入此功能，你直接将com.mining.app.zxing.camera，com.mining.app.zxing.decoding，com.mining.app.zxing.view这三个包拷贝到你的项目中，然后引入相对应的资源进去，我也是从我的项目中直接引用过来的，包名都没改呢，当然还需要引用zxing.jar
• com.example.qr_codescan包里面有一个mipcaactivitycapture,也是直接引入我之前项目的代码的，这个activity主要处理扫描界面的类，比如，扫描成功有声音和振动等等，主要关注里面的handledecode(result result, bitmap barcode)方法，扫描完成之后将扫描到的结果和二维码的bitmap当初参数传递到handledecode(result result, bitmap barcode)里面，我们只需要在里面写出相对应的处理代码即可，其他的地方都不用改得，我这里处理扫描结果和扫描拍的照片

/**
 * 处理扫描结果
 * @param result
 * @param barcode
 */
public void handledecode(result result, bitmap barcode) {
 inactivitytimer.onactivity();
 playbeepsoundandvibrate();
 string resultstring = result.gettext();
 if (resultstring.equals("")) {
  toast.maketext(mipcaactivitycapture.this, "scan failed!", toast.length_short).show();
 }else {
  intent resultintent = new intent();
  bundle bundle = new bundle();
  bundle.putstring("result", resultstring);
  bundle.putparcelable("bitmap", barcode);
  resultintent.putextras(bundle);
  this.setresult(result_ok, resultintent);
 }
 mipcaactivitycapture.this.finish();
}

我对mipcaactivitycapture界面的布局做了自己的改动，先看下效果图，主要是用到framelayout,里面嵌套relativelayout。

布局代码如下

<?xml version="1.0" encoding="utf-8"?>
<framelayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
  android:layout_height="fill_parent" >

 <relativelayout
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" >

  <surfaceview
   android:id="@+id/preview_view"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:layout_gravity="center" />

  <com.mining.app.zxing.view.viewfinderview
   android:id="@+id/viewfinder_view"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content" />

  <include
   android:id="@+id/include1"
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:layout_alignparenttop="true"
   layout="@layout/activity_title" />
 </relativelayout>

</framelayout>

在里面我将界面上面部分写在另一个布局里面，然后include进来，因为这个activity_title在我项目里面还供其他的activity使用，我也是直接拷贝出来的

<?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="wrap_content"
 android:background="@drawable/mmtitle_bg_alpha" >

 <button
  android:id="@+id/button_back"
  android:layout_width="75.0dip"
  android:text="返回"
  android:background="@drawable/mm_title_back_btn"
  android:textcolor="@android:color/white"
  android:layout_height="wrap_content"
  android:layout_centervertical="true"
  android:layout_marginleft="2dip" />

 <textview
  android:id="@+id/textview_title"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_alignbaseline="@+id/button_back"
  android:layout_alignbottom="@+id/button_back"
  android:layout_centerhorizontal="true"
  android:gravity="center_vertical"
  android:text="二维码扫描"
  android:textcolor="@android:color/white"
  android:textsize="18sp" />

</relativelayout>

在我这个demo里面，有一个主界面mainactivity，里面一个button， 一个imageview和一个textview,点击button进入到二维码扫描界面，当扫描ok的时候，回到主界面，将扫描的结果显示到textview，将图片显示到imageview里面，然后你可以不处理图片，我这里随带的加上图片，主界面的布局很简单如下

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:background="#ffe1e0de" >

 <button
  android:id="@+id/button1"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_alignparenttop="true"
  android:text="扫描二维码" />

 <textview
  android:id="@+id/result"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_below="@+id/button1"
  android:lines="2"
  android:gravity="center_horizontal"
  android:textcolor="@android:color/black"
  android:textsize="16sp" />

 <imageview
  android:id="@+id/qrcode_bitmap"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:layout_alignparentleft="true"
  android:layout_below="@+id/result"/>
</relativelayout>

mainactivity里面的代码如下，里面的功能在上面已经说了

package com.example.qr_codescan;


import android.app.activity;
import android.content.intent;
import android.graphics.bitmap;
import android.os.bundle;
import android.view.view;
import android.view.view.onclicklistener;
import android.widget.button;
import android.widget.imageview;
import android.widget.textview;

public class mainactivity extends activity {
 private final static int scannin_grequest_code = 1;
 /**
  * 显示扫描结果
  */
 private textview mtextview ;
 /**
  * 显示扫描拍的图片
  */
 private imageview mimageview;


 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.activity_main);

  mtextview = (textview) findviewbyid(r.id.result);
  mimageview = (imageview) findviewbyid(r.id.qrcode_bitmap);

  //点击按钮跳转到二维码扫描界面，这里用的是startactivityforresult跳转
  //扫描完了之后调到该界面
  button mbutton = (button) findviewbyid(r.id.button1);
  mbutton.setonclicklistener(new onclicklistener() {

   @override
   public void onclick(view v) {
    intent intent = new intent();
    intent.setclass(mainactivity.this, mipcaactivitycapture.class);
    intent.setflags(intent.flag_activity_clear_top);
    startactivityforresult(intent, scannin_grequest_code);
   }
  });
 }


 @override
 protected void onactivityresult(int requestcode, int resultcode, intent data) {
  super.onactivityresult(requestcode, resultcode, data);
  switch (requestcode) {
  case scannin_grequest_code:
   if(resultcode == result_ok){
    bundle bundle = data.getextras();
    //显示扫描到的内容
    mtextview.settext(bundle.getstring("result"));
    //显示
    mimageview.setimagebitmap((bitmap) data.getparcelableextra("bitmap"));
   }
   break;
  }
 }

}

上面的代码还是比较简单，但是要想做出像微信那样只的扫描框，紧紧上面的代码是没有那种效果的，我们必须重写com.mining.app.zxing.view包下面的viewfinderview类，微信里面的都是用的图片，我是自己画出来的，代码注释的比较清楚，大家直接看代码吧，相信你能理解的，如果你要修改扫描框的大小，去cameramanager类里面修改

/*
 * copyright (c) 2008 zxing authors
 *
 * licensed under the apache license, version 2.0 (the "license");
 * you may not use this file except in compliance with the license.
 * you may obtain a copy of the license at
 *
 *  *
 * unless required by applicable law or agreed to in writing, software
 * distributed under the license is distributed on an "as is" basis,
 * without warranties or conditions of any kind, either express or implied.
 * see the license for the specific language governing permissions and
 * limitations under the license.
 */

package com.mining.app.zxing.view;

import java.util.collection;
import java.util.hashset;

import android.content.context;
import android.content.res.resources;
import android.graphics.bitmap;
import android.graphics.canvas;
import android.graphics.color;
import android.graphics.paint;
import android.graphics.rect;
import android.graphics.typeface;
import android.util.attributeset;
import android.view.view;

import com.example.qr_codescan.r;
import com.google.zxing.resultpoint;
import com.mining.app.zxing.camera.cameramanager;

/**
 * this view is overlaid on top of the camera preview. it adds the viewfinder
 * rectangle and partial transparency outside it, as well as the laser scanner
 * animation and result points.
 *
 */
public final class viewfinderview extends view {
 private static final string tag = "log";
 /**
  * 刷新界面的时间
  */
 private static final long animation_delay = 10l;
 private static final int opaque = 0xff;

 /**
  * 四个绿色边角对应的长度
  */
 private int screenrate;

 /**
  * 四个绿色边角对应的宽度
  */
 private static final int corner_width = 10;
 /**
  * 扫描框中的中间线的宽度
  */
 private static final int middle_line_width = 6;

 /**
  * 扫描框中的中间线的与扫描框左右的间隙
  */
 private static final int middle_line_padding = 5;

 /**
  * 中间那条线每次刷新移动的距离
  */
 private static final int speen_distance = 5;

 /**
  * 手机的屏幕密度
  */
 private static float density;
 /**
  * 字体大小
  */
 private static final int text_size = 16;
 /**
  * 字体距离扫描框下面的距离
  */
 private static final int text_padding_top = 30;

 /**
  * 画笔对象的引用
  */
 private paint paint;

 /**
  * 中间滑动线的最顶端位置
  */
 private int slidetop;

 /**
  * 中间滑动线的最底端位置
  */
 private int slidebottom;

 private bitmap resultbitmap;
 private final int maskcolor;
 private final int resultcolor;

 private final int resultpointcolor;
 private collection<resultpoint> possibleresultpoints;
 private collection<resultpoint> lastpossibleresultpoints;

 boolean isfirst;

 public viewfinderview(context context, attributeset attrs) {
  super(context, attrs);

  density = context.getresources().getdisplaymetrics().density;
  //将像素转换成dp
  screenrate = (int)(20 * density);

  paint = new paint();
  resources resources = getresources();
  maskcolor = resources.getcolor(r.color.viewfinder_mask);
  resultcolor = resources.getcolor(r.color.result_view);

  resultpointcolor = resources.getcolor(r.color.possible_result_points);
  possibleresultpoints = new hashset<resultpoint>(5);
 }

 @override
 public void ondraw(canvas canvas) {
  //中间的扫描框，你要修改扫描框的大小，去cameramanager里面修改
  rect frame = cameramanager.get().getframingrect();
  if (frame == null) {
   return;
  }

  //初始化中间线滑动的最上边和最下边
  if(!isfirst){
   isfirst = true;
   slidetop = frame.top;
   slidebottom = frame.bottom;
  }

  //获取屏幕的宽和高
  int width = canvas.getwidth();
  int height = canvas.getheight();

  paint.setcolor(resultbitmap != null ? resultcolor : maskcolor);

  //画出扫描框外面的阴影部分，共四个部分，扫描框的上面到屏幕上面，扫描框的下面到屏幕下面
  //扫描框的左边面到屏幕左边，扫描框的右边到屏幕右边
  canvas.drawrect(0, 0, width, frame.top, paint);
  canvas.drawrect(0, frame.top, frame.left, frame.bottom + 1, paint);
  canvas.drawrect(frame.right + 1, frame.top, width, frame.bottom + 1,
    paint);
  canvas.drawrect(0, frame.bottom + 1, width, height, paint);



  if (resultbitmap != null) {
   // draw the opaque result bitmap over the scanning rectangle
   paint.setalpha(opaque);
   canvas.drawbitmap(resultbitmap, frame.left, frame.top, paint);
  } else {

   //画扫描框边上的角，总共8个部分
   paint.setcolor(color.green);
   canvas.drawrect(frame.left, frame.top, frame.left + screenrate,
     frame.top + corner_width, paint);
   canvas.drawrect(frame.left, frame.top, frame.left + corner_width, frame.top
     + screenrate, paint);
   canvas.drawrect(frame.right - screenrate, frame.top, frame.right,
     frame.top + corner_width, paint);
   canvas.drawrect(frame.right - corner_width, frame.top, frame.right, frame.top
     + screenrate, paint);
   canvas.drawrect(frame.left, frame.bottom - corner_width, frame.left
     + screenrate, frame.bottom, paint);
   canvas.drawrect(frame.left, frame.bottom - screenrate,
     frame.left + corner_width, frame.bottom, paint);
   canvas.drawrect(frame.right - screenrate, frame.bottom - corner_width,
     frame.right, frame.bottom, paint);
   canvas.drawrect(frame.right - corner_width, frame.bottom - screenrate,
     frame.right, frame.bottom, paint);


   //绘制中间的线,每次刷新界面，中间的线往下移动speen_distance
   slidetop += speen_distance;
   if(slidetop >= frame.bottom){
    slidetop = frame.top;
   }
   canvas.drawrect(frame.left + middle_line_padding, slidetop - middle_line_width/2, frame.right - middle_line_padding,slidetop + middle_line_width/2, paint);


   //画扫描框下面的字
   paint.setcolor(color.white);
   paint.settextsize(text_size * density);
   paint.setalpha(0x40);
   paint.settypeface(typeface.create("system", typeface.bold));
   canvas.drawtext(getresources().getstring(r.string.scan_text), frame.left, (float) (frame.bottom + (float)text_padding_top *density), paint);



   collection<resultpoint> currentpossible = possibleresultpoints;
   collection<resultpoint> currentlast = lastpossibleresultpoints;
   if (currentpossible.isempty()) {
    lastpossibleresultpoints = null;
   } else {
    possibleresultpoints = new hashset<resultpoint>(5);
    lastpossibleresultpoints = currentpossible;
    paint.setalpha(opaque);
    paint.setcolor(resultpointcolor);
    for (resultpoint point : currentpossible) {
     canvas.drawcircle(frame.left + point.getx(), frame.top
       + point.gety(), 6.0f, paint);
    }
   }
   if (currentlast != null) {
    paint.setalpha(opaque / 2);
    paint.setcolor(resultpointcolor);
    for (resultpoint point : currentlast) {
     canvas.drawcircle(frame.left + point.getx(), frame.top
       + point.gety(), 3.0f, paint);
    }
   }


   //只刷新扫描框的内容，其他地方不刷新
   postinvalidatedelayed(animation_delay, frame.left, frame.top,
     frame.right, frame.bottom);

  }
 }

 public void drawviewfinder() {
  resultbitmap = null;
  invalidate();
 }

 /**
  * draw a bitmap with the result points highlighted instead of the live
  * scanning display.
  *
  * @param barcode
  *   an image of the decoded barcode.
  */
 public void drawresultbitmap(bitmap barcode) {
  resultbitmap = barcode;
  invalidate();
 }

 public void addpossibleresultpoint(resultpoint point) {
  possibleresultpoints.add(point);
 }

}

上面的代码中，中间那根线微信是用的图片，我这里是画的，如果你想更加仿真点就将下面的代码

canvas.drawrect(frame.left + middle_line_padding, slidetop - middle_line_width/2, frame.right - middle_line_padding,slidetop + middle_line_width/2, paint);

改成

rect linerect = new rect();
   linerect.left = frame.left;
   linerect.right = frame.right;
   linerect.top = slidetop;
   linerect.bottom = slidetop + 18;
   canvas.drawbitmap(((bitmapdrawable)(getresources().getdrawable(r.drawable.qrcode_scan_line))).getbitmap(), null, linerect, paint);

那条扫描线自己去微信里面找一下，我贴出来的失真了，下载微信apk,将后缀名改成zip,然后解压就行了
画扫描框下面字体的代码需要修改下，这样子能根据字体自动排列在中间，如果字太长我没有处理，那个要自动换行，你可以自行处理

paint.setcolor(color.white);
paint.settextsize(text_size * density);
paint.setalpha(0x40);
paint.settypeface(typeface.default_bold);
string text = getresources().getstring(r.string.r.string.scan_text);
float textwidth = paint.measuretext(text);

canvas.drawtext(text, (width - textwidth)/2, (float) (frame.bottom + (float)text_padding_top *density), paint)

运行界面截图，其中中间的那根绿色的线会上下移动，跟微信的效果差不多，当然运行你还需要相对应的权限问题。

以上就是本文的全部内容，希望对大家学习android软件编程有所帮助。