安卓 高速扫码开发

Android高速扫码开发是变色龙非常重要的技术，它可以让我们在应用中快速扫描二维码和条形码。在实现高速扫码的过程中，需要了解相关的原理和技术。

二维码和条形码是现代生活中常见的信息承载形式，其实现就落在了扫码识别技术上。在Android平台中，我们可以通过使用ZXing库来实现高速扫码功能。下面对ZXing库的使用进行详细介绍：

1. ZXing库的导入

在build.gradle文件中添加ZXing库的依赖：

```gradle

compile 'com.google.zxing:core:3.2.1'

compile 'com.journeyapps:zxing-android-embedded:3.6.0'

```

2. 权限的获取与代码实现

使用扫码功能需要获取摄像头权限，可以通过以下代码实现：

```java

private static final int PERMISSION_CAMERA = 100;

private static final String[] PERMISSIONS = {Manifest.permission.CAMERA};

private static final int REQUEST_CAMERA = 0x01;

private boolean checkPermission(String... permissions) {

boolean granted = false;

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

for (String permission : permissions) {

if (checkSelfPermission(permission) == PackageManager.PERMISSION_GRANTED) {

granted = true;

}

}

} else {

granted = true;

}

return granted;

}

private void requestPermission(String[] permissions, int requestCode) {

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

requestPermissions(permissions, requestCode);

}

}

private void showPermissionDialog(int requestCode) {

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

requestPermission(PERMISSIONS, requestCode);

}

}

private void checkCameraPermission() {

if (checkPermission(PERMISSIONS)) {

startScanQRCode();

} else {

showPermissionDialog(REQUEST_CAMERA);

}

}

@Override

public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,

@NonNull int[] grantResults) {

super.onRequestPermissionsResult(requestCode, permissions, grantResults);

if (requestCode == REQUEST_CAMERA && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

startScanQRCode();

} else {

Toast.makeText(this, "Permission denied", Toast.LENGTH_SHORT).show();

}

}

private void startScanQRCode() {

IntentIntegrator integrator = new IntentIntegrator(MainActivity.this);

integrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE_TYPES);

integrator.setPrompt("Scan a QR code");

integrator.setCameraId(0);

integrator.setBeepEnabled(false);

integrator.setBarcodeImageEnabled(true);

integrator.initiateScan();

}

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

super.onActivityResult(requestCode, resultCode, data);

IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);

if (result != null && result.getContents() != null) {

String content = result.getContents();

Toast.makeText(this, content, Toast.LENGTH_SHORT).show();

}

}

```

3. 界面的构建

我们可以在XML布局文件中创建一个视图，用于实现扫码的界面，如下：

```xml

xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent">

android:id="@+id/camera_preview"

android:layout_width="match_parent"

android:layout_height="0dp"

android:layout_weight="1"/>

```

4. 扫码功能的实现

通过ZXing库来实现扫码的逻辑如下：

```java

private SurfaceHolder.Callback surfaceListener = new SurfaceHolder.Callback() {

public void surfaceCreated(SurfaceHolder holder) {

try {

cameraSource.start(holder);

} catch (IOException e) {

Log.e(TAG, e.getMessage());

}

}

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

// ...

}

public void surfaceDestroyed(SurfaceHolder holder) {

cameraSource.stop();

}

};

private void setupCameraSource() {

BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(this).build();

cameraSource = new CameraSource.Builder(this, barcodeDetector)

.setFacing(CameraSource.CAMERA_FACING_BACK)

.setRequestedPreviewSize(1600, 1024)

.setRequestedFps(15.0f)

.setAutoFocusEnabled(true)

.build();

preview = (SurfaceView) findViewById(R.id.camera_preview);

preview.getHolder().addCallback(surfaceListener);

barcodeDetector.setProcessor(new Detector.Processor() {

@Override

public void release() {}

@Override

public void receiveDetections(Detector.Detections detections) {

final SparseArray barcodeList = detections.getDetectedItems();

if (barcodeList.size() != 0) {

runOnUiThread(new Runnable() {

@Override

public void run() {

String scanResult = barcodeList.valueAt(0).displayValue;

Toast.makeText(MainActivity.this, scanResult, Toast.LENGTH_SHORT).show();

}

});

}

}

});

}

```

以上就是安卓高速扫码开发的过程，在这个过程中，需要理解底层的原理和使用的技术，同时对ZXing库的使用进行了详细的介绍。希望这篇文章对您的学习有所帮助。