Android 实现扫描二维码
2016-03-10 本文已影响2242人
晓峰残月
1、如何使用
1.新建一个布局
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:showIn="@layout/activity_capture">
<Button
android:id="@+id/capture_bt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="扫描二维码"
/>
<TextView
android:id="@+id/capture_tv"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/capture_bt"
/>
<ImageView
android:id="@+id/capture_iv"
android:layout_width="fill_parent"
android:layout_height="200dp"
android:scaleType="centerInside"
android:layout_below="@+id/capture_tv"
/>
</RelativeLayout>
布局很简单，一个跳转到扫描界面的Button，一个用于显示返回扫描结果的TextView和一个用于显示扫描截取图片的ImageView。
2.Activity中的使用
private void initView() {
capture = (Button) this.findViewById(R.id.capture_bt);
tv = (TextView) this.findViewById(R.id.capture_tv);
iv = (ImageView) this.findViewById(R.id.capture_iv);
capture.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent();
intent.setClass(CaptureActivity.this, com.jwenfeng.fastdev.zxing.Activity.CaptureActivity.class);
intent.putExtra("path", Environment.getExternalStorageDirectory().getPath()+"/QRcode/");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivityForResult(intent, SCANNIN_GREQUEST_CODE);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case SCANNIN_GREQUEST_CODE:
if(resultCode == RESULT_OK){
Bundle bundle = data.getExtras();
//显示扫描到的内容
tv.setText(bundle.getString("result"));
iv.setImageBitmap(BitmapFactory.decodeFile(bundle.getString("filepath")));
}
break;
}
}
Activity 中就是跳转到扫描的界面，在onActivityResult处理返回的数据
2、工作原理
在扫描界面这个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
/**
* 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(CaptureActivity.this, "Scan failed!", Toast.LENGTH_SHORT).show();
} else {
Intent resultIntent = new Intent();
Bundle bundle = new Bundle();
bundle.putString("result", resultString);
if (path == null || path.equals("")){
}else{
if (!new File(path).exists()){
new File(path).mkdir();
}
String fileName = System.currentTimeMillis()+".jpg";
saveQRcodeToSDcard(path+fileName,barcode);
bundle.putString("filepath", path + fileName);
}
//bundle.putParcelable("bitmap", barcode);
resultIntent.putExtras(bundle);
this.setResult(RESULT_OK, resultIntent);
}
CaptureActivity.this.finish();
}
参考网上http://blog.csdn.net/xiaanming/article/details/10163203
这篇文章修改了一下扫码的界面，代码注释很全。
package com.jwenfeng.fastdev.zxing.view;/*
* 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.
*/
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.google.zxing.ResultPoint;
import com.jwenfeng.fastdev.R;
import com.jwenfeng.fastdev.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;
/**
* 将扫描的二维码拍下来，这里没有这个功能，暂时不考虑
*/
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);
}
}
在 CaptureActivity 中创建CaptureActivityHandler
handler = new CaptureActivityHandler(this, decodeFormats, characterSet);
在CaptureActivityHandler的初始化启动扫描解码的线程，在 handler 中对handleDecode回调传递参数
public CaptureActivityHandler(CaptureActivity activity, Vector<BarcodeFormat> decodeFormats,
String characterSet) {
this.activity = activity;
decodeThread = new DecodeThread(activity, decodeFormats, characterSet,
new ViewfinderResultPointCallback(activity.getViewfinderView()));
decodeThread.start();
state = State.SUCCESS;
// Start ourselves capturing previews and decoding.
CameraManager.get().startPreview();
restartPreviewAndDecode();
}
@Override
public void handleMessage(Message message) {
if (message.what == R.id.auto_focus) {//Log.d(TAG, "Got auto-focus message");
// When one auto focus pass finishes, start another. This is the closest thing to
// continuous AF. It does seem to hunt a bit, but I'm not sure what else to do.
if (state == State.PREVIEW) {
CameraManager.get().requestAutoFocus(this, R.id.auto_focus);
}
} else if (message.what == R.id.restart_preview) {
Log.d(TAG, "Got restart preview message");
restartPreviewAndDecode();
} else if (message.what == R.id.decode_succeeded) {
Log.d(TAG, "Got decode succeeded message");
state = State.SUCCESS;
Bundle bundle = message.getData();
/***********************************************************************/
Bitmap barcode = bundle == null ? null :
(Bitmap) bundle.getParcelable(DecodeThread.BARCODE_BITMAP);
activity.handleDecode((Result) message.obj, barcode);
} else if (message.what == R.id.decode_failed) {// We're decoding as fast as possible, so when one decode fails, start another.
state = State.PREVIEW;
CameraManager.get().requestPreviewFrame(decodeThread.getHandler(), R.id.decode);
} else if (message.what == R.id.return_scan_result) {
Log.d(TAG, "Got return scan result message");
activity.setResult(Activity.RESULT_OK, (Intent) message.obj);
activity.finish();
} else if (message.what == R.id.launch_product_query) {
Log.d(TAG, "Got product query message");
String url = (String) message.obj;
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
activity.startActivity(intent);
}
}
最后附上demo的效果图
S60310-163413.jpg
S60310-163501.jpg
S60310-163507.jpg
最后别忘了导入 core.jar 的jar包
转载请注明转载地址：http://www.jianshu.com/p/5ee933cf1ed9
Android 实现扫描二维码
如有什么不对或者不规范的地方请留言或私信我，非常感谢
