Litchi 2013-09-02
了解二维码这个东西还是从微信中,当时微信推出二维码扫描功能,自己感觉挺新颖的,从一张图片中扫一下竟然能直接加好友,不可思议啊,那时候还不了解二维码,呵呵,然后做项目的时候,老板说要加上二维码扫描功能,然后自己的屁颠屁颠的去百度,google啥的,发现很多朋友都有介绍二维码扫描的功能,然后我就跟着人家的介绍自己搞起了二维码扫描功能,跟着人家的帖子,很快我的项目就加入了扫描二维码的功能,然后自己还很开心。
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,里面的图片也是从微信里面拿出来的,平常我看到需要什么图片就去微信里面找,没有美工的公司的程序员就是苦逼
<?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 * * http://www.apache.org/licenses/LICENSE-2.0 * * 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,有兴趣的朋友可以去下载demo
从8点多写这篇博客写到现在,看起来这么点字,但实际上还是比较耗时间的,如果你觉得这篇文章对你有帮助,你就顶一下,哈哈,洗澡睡觉去了,上面的项目中还有一些资源文件我没有贴出来,想要看效果可以下载源码
项目源码,点击下载http://download.csdn.net/detail/xiaanming/5990219