1. 权限问题：确保在AndroidManifest.xml文件中添加了所需的权限，包括网络或相机权限。

2. 代码问题：使用支持QR码扫描的开源库，如Zxing或Google Vision API。

// 使用Zxing的示例代码 compile 'com.google.zxing:core:3.3.2'

// 在build.gradle中添加调用的类 compile 'me.dm7.barcodescanner:zxing:1.9.8'

// In the layout XML file

// In the activity or fragment public class MyActivity extends AppCompatActivity implements ZXingScannerView.ResultHandler { private ZXingScannerView mScannerView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mScannerView = new ZXingScannerView(this); // Initiate the scanner library object
    setContentView(mScannerView); // Set the scanner view as the content view
}

@Override
public void onResume() {
    super.onResume();
    mScannerView.setResultHandler(this); // Register ourselves as a handler for scan results.
    mScannerView.startCamera(); // Start camera on resume
}

@Override
public void onPause() {
    super.onPause();
    mScannerView.stopCamera(); // Stop camera on pause
}

@Override
public void handleResult(Result result) {
    // Do something with the result here
    Toast.makeText(this, result.getText(), Toast.LENGTH_LONG).show();
    // Resume scanning
    mScannerView.resumeCameraPreview(this);
}

}

3. 其他问题：确保QR码的清晰度和大小足