Android之二维码扫描的总结

第一步：导入zxing.jar包

第二步：项目中导入相关的类

关键代码：

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

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);      }    }