andorid使用zxing实现扫码

要在 Android 中使用 ZXing 实现扫码，需要进行以下步骤：

1. 在 build.gradle 文件中添加以下依赖：

dependencies {
    implementation 'com.google.zxing:core:3.4.1'
    implementation 'com.journeyapps:zxing-android-embedded:3.5.0'
}

2. 在布局文件中添加一个 SurfaceView 用于预览摄像头捕获的图像，并添加一个按钮用于触发扫码操作：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

   <Button
       android:id="@+id/scan_button"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Scan"
       android:layout_alignParentBottom="true"
       android:layout_centerHorizontal="true" />

</RelativeLayout>

3. 在 Activity 中实现扫码逻辑。首先，初始化 ZXing 的核心类 CaptureManager 和 ViewfinderView，然后在 onResume() 方法中启动摄像头预览，并在 onPause() 方法中停止预览。在按钮点击事件中触发扫码操作，并在 onActivityResult() 方法中获取扫码结果。

public class ScanActivity extends AppCompatActivity implements OnScanListener {

    private CaptureManager captureManager;
    private SurfaceView surfaceView;
    private ViewfinderView viewfinderView;
    private Button scanButton;

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

        surfaceView = findViewById(R.id.surface_view);
        viewfinderView = findViewById(R.id.viewfinder_view);
        scanButton = findViewById(R.id.scan_button);

        captureManager = new CaptureManager(this, surfaceView, viewfinderView);
        captureManager.initializeFromIntent(getIntent(), savedInstanceState);
        captureManager.setOnScanListener(this);

        scanButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                captureManager.decode();
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        captureManager.onResume();
    }

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

    @Override
    protected void onDestroy() {
        super.onDestroy();
        captureManager.onDestroy();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        captureManager.onSaveInstanceState(outState);
    }

    @Override
    public void onScanResult(String result) {
        Toast.makeText(this, result, Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onScanError(Exception e) {
        Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onScanCancel() {
        // Do nothing
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        captureManager.onActivityResult(requestCode, resultCode, data);
    }

}

以上就是使用 ZXing 实现扫码的基本步骤。你可以根据实际需求对代码进行修改和扩展。