Check whether there is a QR code in the picture

Requirement specification

Select a picture from your phone album , Or take a picture , Then use the code to detect whether there is a QR code in the picture , And give the corresponding prompt （Toast）.

This paper uses the function of opening the system album to select pictures , The technical support used is Huawei's dependent library , Let's start with the concrete implementation .

Configuration work

Project dependency libraries are based on  

androidX

Of ,app Next

build.gradle

Add the following configuration ：

//  Whether there is QR code in the code scanning picture
implementation 'com.huawei.agconnect:agconnect-core:1.4.0.300'
implementation 'com.huawei.hms:scanplus:1.2.4.300'


Project

build.gradle

The complete code is as follows ：

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
 repositories {
 google()
 jcenter()
 maven { url 'https://developer.huawei.com/repo/' }
 }
 dependencies {
 classpath "com.android.tools.build:gradle:4.0.0"

 classpath 'com.huawei.agconnect:agcp:1.4.1.300'
 // NOTE: Do not place your application dependencies here; they belong
 // in the individual module build.gradle files
 }
}

allprojects {
 repositories {
 google()
 jcenter()
 maven {url 'https://developer.huawei.com/repo/'}
 }
}

task clean(type: Delete) {
 delete rootProject.buildDir
}


The example has only one page , Just add a button , Click the event to trigger the jump to the album, select the picture and call back

onActivityResult()

Judge whether there is QR code in , The complete code of this method is as follows ：

@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
 if (resultCode == RESULT_OK) {
 try {
 Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), data.getData());
 //“QRCODE_SCAN_TYPE ” and “ DATAMATRIX_SCAN_TYPE It means scan only QR and Data Matrix Code of
 HmsScanAnalyzerOptions options = new HmsScanAnalyzerOptions.Creator().setHmsScanTypes(HmsScan.QRCODE_SCAN_TYPE, HmsScan.DATAMATRIX_SCAN_TYPE).setPhotoMode(true).create();
 HmsScan[] hmsScans = ScanUtil.decodeWithBitmap(this, bitmap, options);
 // Process scan results
 if (hmsScans != null && hmsScans.length > 0) {
 // Show scan results
 showResult(hmsScans);
 Toast.makeText(this, " Find the QR code ", Toast.LENGTH_SHORT).show();
 } else {
 Toast.makeText(this, " QR code not found ", Toast.LENGTH_SHORT).show();
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 super.onActivityResult(requestCode, resultCode, data);
}

private void showResult(HmsScan[] hmsScans) {
 for (int i = 0; i < hmsScans.length; i++) {
 Log.e(TAG, hmsScans[i].showResult);
 }
}


Here we need to pay attention to ：

• Read and write file permissions in the manifest file must be added

• Dynamic application permission must be added in the code （ Omitted from example ）

• adapter Android7.0+ Uri Cannot be called by other applications ``FileUriExposedException` Abnormal problems （ Omitted from example ）

Jump to system photo album code ：

//data yes Intent type ,data.getData Is the barcode image to be scanned Uri
Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, REQUEST_OK);


The above work has been completed correctly , Then you can test , The actual effect will not be demonstrated here , There's nothing to see , Just get started .

Summary

Huawei Technology really can not be underestimated , Has provided a lot of powerful open source dependencies , In this paper, the two-dimensional code recognition technology in the picture is one of them , In addition, if you continue to use

zxing

  To scan the code , Then I recommend you to use the technology provided by Huawei , Speed is more awesome. .

I am an Android Development Engineer , I'm studying recently Java Back end knowledge , Keep learning every day , It doesn't take long to master a skill , come on. ！