我尝试创建一个可以扫描二维码并处理其数据的简单应用。
我是通过以下教程完成的：https://www.c-sharpcorner.com/article/xamarin-android-qr-code-reader-by-mobile-camera/
该代码可以编译并正常运行-摄像机图像可以正确显示，但是现在我在几种不同的设备上测试了该代码，在某些设备上，他可以将qr代码保存到相机中并读取正确的数据，但不幸的是，在其他一些设备上却没有。不管二维码到相机的距离如何。
相机质量本身并不是我想的问题，相机图像的显示质量似乎不错，至少对于我来说，以及在同一设备上安装外部qr应用程序时（我自己）应用程序无法读取二维码，此外部应用程序可以读取二维码而没有任何问题。
这是什么原因？如何提高> install.packages("rgl")
Installing package into ‘/home/xxxxxx/R/x86_64-redhat-linux-gnu-library/3.4’
(as ‘lib’ is unspecified)
trying URL 'http://cran.rstudio.com/src/contrib/rgl_0.99.16.tar.gz'
Content type 'application/x-gzip' length 3058794 bytes (2.9 MB)
==================================================
downloaded 2.9 MB
* installing *source* package ‘rgl’ ...
** package ‘rgl’ successfully unpacked and MD5 sums checked
checking for gcc... gcc -m64 -std=gnu99
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc -m64 -std=gnu99 accepts -g... yes
checking for gcc -m64 -std=gnu99 option to accept ISO C89... none needed
checking how to run the C preprocessor... gcc -m64 -std=gnu99 -E
checking for gcc... (cached) gcc -m64 -std=gnu99
checking whether we are using the GNU C compiler... (cached) yes
checking whether gcc -m64 -std=gnu99 accepts -g... (cached) yes
checking for gcc -m64 -std=gnu99 option to accept ISO C89... (cached) none needed
checking for libpng-config... yes
configure: using libpng-config
configure: using libpng dynamic linkage
checking for X... libraries , headers
checking GL/gl.h usability... no
checking GL/gl.h presence... no
checking for GL/gl.h... no
checking GL/glu.h usability... no
checking GL/glu.h presence... no
checking for GL/glu.h... no
configure: error: missing required header GL/gl.h
的质量，以便他能够在所有设备上读取二维码？
让我简要分享一下我的看法：
-三星Galaxy SIII Neo：自己的应用程序（下面的代码）可以工作，因此能够读取和处理二维码，也可以读取和处理外部二维码应用程序
-Acer One 10：相同的应用程序，相机图像显示良好（类似于Samsung设备），但是持有相同的qr码（上面已起作用）来扫描相机，则没有效果。无论其与设备的距离如何。但是，始终可以使用外部qr应用程序。
-三星Galaxy S4：与Acer One 10相同
到目前为止，请允许我最终分享我的代码，也许对我来说更容易：
QrCodeScanner.axml：
BarcodeDetectorQrCodeScannerActivity.cs：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<SurfaceView
android:layout_width="480dp"
android:layout_height="480dp"
android:layout_centerInParent="true"
android:id="@+id/surfaceView" />
<TextView
android:text="Please focus qr code
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/surfaceView"
android:textSize="20sp"
android:layout_marginTop="20dp"
android:gravity="center_horizontal"
android:id="@+id/textView" />
</RelativeLayout>
AndroidManifest.xml：
//...
using Android.Gms.Vision;
using Android.Gms.Vision.Barcodes;
using Android.Support.V4.App;
using Android.Support.V7.App;
using static Android.Gms.Vision.Detector;
//...
[Activity(Label = "QrCodeScannerActivity")]
public class QrCodeScannerActivity : AppCompatActivity, ISurfaceHolderCallback, IProcessor
{
SurfaceView cameraPreview;
TextView resultTxt;
BarcodeDetector barcodeDetector;
CameraSource cameraSource;
const int RequestCameraPermissionID = 1001;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.QrCodeScanner);
cameraPreview = FindViewById<SurfaceView>(Resource.Id.surfaceView);
resultTxt = FindViewById<TextView>(Resource.Id.textView);
barcodeDetector = new BarcodeDetector
.Builder(this)
.SetBarcodeFormats(BarcodeFormat.QrCode)
.Build();
cameraSource = new CameraSource
.Builder(this, barcodeDetector)
.SetAutoFocusEnabled(true)
.SetFacing(CameraFacing.Front)
.SetRequestedPreviewSize(480, 480)
.SetRequestedFps(30.0f)
.Build();
cameraPreview.Holder.AddCallback(this);
barcodeDetector.SetProcessor(this);
}
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
{
switch (requestCode)
{
case RequestCameraPermissionID:
{
if (grantResults[0] == Permission.Granted)
{
if (ActivityCompat.CheckSelfPermission(ApplicationContext, Manifest.Permission.Camera) != Android.Content.PM.Permission.Granted)
{
ActivityCompat.RequestPermissions(this, new string[]
{
Manifest.Permission.Camera
}, RequestCameraPermissionID);
return;
}
try
{
cameraSource.Start(cameraPreview.Holder);
}
catch (InvalidOperationException)
{
}
}
}
break;
}
}
public void SurfaceChanged(ISurfaceHolder holder, [GeneratedEnum] Format format, int width, int height)
{
}
public void SurfaceCreated(ISurfaceHolder holder)
{
if (ActivityCompat.CheckSelfPermission(ApplicationContext, Manifest.Permission.Camera) != Android.Content.PM.Permission.Granted)
{
ActivityCompat.RequestPermissions(this, new string[]
{
Manifest.Permission.Camera
}, RequestCameraPermissionID);
return;
}
try
{
cameraSource.Start(cameraPreview.Holder);
}
catch (InvalidOperationException)
{
}
}
public void SurfaceDestroyed(ISurfaceHolder holder)
{
cameraSource.Stop();
}
public void ReceiveDetections(Detections detections)
{
SparseArray qrcodes = detections.DetectedItems;
if (qrcodes.Size() != 0)
{
resultTxt.Post(() =>
{
Vibrator vib = (Vibrator)GetSystemService(Context.VibratorService);
vib.Vibrate(1000);
resultTxt.Text = ((Barcode)qrcodes.ValueAt(0)).RawValue;
});
}
}
public void Release()
{
}
}
真的很感谢每一个答案。
最诚挚的问候