android 二维码扫描

您可以使用ZXing库在Android应用程序中实现二维码扫描功能。以下是步骤：

1.添加依赖项：在您的应用程序build.gradle文件中添加以下依赖项：

implementation 'com.google.zxing:core:3.4.1'
implementation 'com.journeyapps:zxing-android-embedded:3.6.0'

2.在您的布局文件中添加一个SurfaceView元素，用于相机预览。

<SurfaceView
    android:id="@+id/surfaceView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

3.创建一个扫描器类：创建一个名为QRCodeScanner的类，该类实现ZXing库的接口，并处理扫描结果。

public class QRCodeScanner implements ZXingScannerView.ResultHandler {
    private Context mContext;
    private ZXingScannerView mScannerView;
    private OnScanCompleteListener mListener;

    public QRCodeScanner(Context context, ViewGroup contentFrame) {
        mContext = context;
        mScannerView = new ZXingScannerView(context);
        contentFrame.addView(mScannerView);
    }

    public void startScan() {
        mScannerView.setResultHandler(this);
        mScannerView.startCamera();
    }

    public void stopScan() {
        mScannerView.stopCamera();
    }

    @Override
    public void handleResult(Result result) {
        mListener.onScanComplete(result.getText());
    }

    public interface OnScanCompleteListener {
        void onScanComplete(String result);
    }

    public void setOnScanCompleteListener(OnScanCompleteListener listener) {
        mListener = listener;
    }
}

4.在您的活动或碎片中使用QRCodeScanner：在onCreate方法中创建QRCodeScanner对象，并在需要扫描二维码时使用startScan方法。您还需要实现OnScanCompleteListener接口，以便在扫描完成时处理结果。

public class ScanActivity extends AppCompatActivity implements QRCodeScanner.OnScanCompleteListener {
    private QRCodeScanner mScanner;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_scan);

        mScanner = new QRCodeScanner(this, (ViewGroup) findViewById(R.id.content_frame));
        mScanner.setOnScanCompleteListener(this);

        Button scanButton = findViewById(R.id.scan_button);
        scanButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mScanner.startScan();
            }
        });
    }

    @Override
    protected void onPause() {
        super.onPause();
        mScanner.stopScan();
    }

    @Override
    public void onScanComplete(String result) {
        Toast.makeText(this, "Scanned: " + result, Toast.LENGTH_SHORT).show();
    }
}

这些步骤可以帮助您在Android应用程序中实现二维码扫描功能。