Android基于google Zxing实现各类二维码扫描效果

2019-12-10 19:06:54王振洲

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); 
  } 
 
}