我跟隨此tutorial瞭解如何構建可掃描QR碼的Android應用程序。使用Android的Mobile Vision API掃描QR代碼
以下是完整的代碼。我添加了像使用compile 'com.google.android.gms:play-services:7.8.0'
這樣的等級的Google Play服務。
的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="bitinvent.io.qrscanner" >
<meta-data android:name="com.google.android.gms.vision.DEPENDENCIES" android:value="barcode"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.CAMERA"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme" >
<activity android:name=".MainActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
activity_main.xml中
<?xml version="1.0" encoding="utf-8"?>
<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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<SurfaceView
android:id="@+id/cameraView"
android:layout_width="640px"
android:layout_height="480px"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"/>
<TextView
android:id="@+id/infoTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toRightOf="@+id/cameraView"
android:layout_marginLeft="16dp"
android:text="Nothing to read"
android:textSize="20sp"/>
</RelativeLayout>
MainActivity.java
package bitinvent.io.qrscanner;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseArray;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.TextView;
import com.google.android.gms.vision.CameraSource;
import com.google.android.gms.vision.Detector;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;
import java.io.IOException;
public class MainActivity extends Activity {
private SurfaceView cameraView;
private TextView barcodeInfo;
private CameraSource cameraSource;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
cameraView = (SurfaceView) findViewById(R.id.cameraView);
barcodeInfo = (TextView) findViewById(R.id.infoTextView);
BarcodeDetector detector = new BarcodeDetector.Builder(this).setBarcodeFormats(Barcode.QR_CODE).build();
cameraSource = new CameraSource.Builder(this, detector).setRequestedPreviewSize(640, 480).build();
cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
cameraSource.start(cameraView.getHolder());
} catch (IOException e) {
Log.e("CAMERA SOURCE", e.getMessage());
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
cameraSource.stop();
}
});
detector.setProcessor(new Detector.Processor<Barcode>() {
@Override
public void release() {
}
@Override
public void receiveDetections(Detector.Detections<Barcode> detections) {
final SparseArray<Barcode> barcodes = detections.getDetectedItems();
if (barcodes.size() != 0) {
barcodeInfo.post(new Runnable() {
@Override
public void run() {
barcodeInfo.setText(barcodes.valueAt(0).displayValue);
}
});
}
}
});
}
}
我在運行Android 4.4.2的HTC Desire 816上測試了這一點。但它似乎並不奏效。相機視圖是活動的,但是當指向QR碼時,它不會檢測到任何東西。但是也不會出現錯誤或崩潰。
我錯過了什麼嗎?
嗨,我知道這是一個相當古老的問題,但我面臨與Android 4.4.2相同的問題。在Android 6上它工作正常,但在這個版本中,qr-code從來沒有得到任何結果..你知道爲什麼嗎? –
@PierGiorgioMisley不,我找不到這個問題的解決方案。抱歉。 – Isuru
好的非常感謝你,如果我找到解決方法,我會告訴你一些事情 –