扫描仪类(system.in)在android studio和build.gradle中的更改不起作用

implementation 'com.google.zxing:core:3.4.0'
implementation 'com.journeyapps:zxing-android-embedded:4.2.0'

import android.content.Intent;
import android.os.Bundle;

import androidx.appcompat.app.AppCompatActivity;

import com.google.zxing.integration.android.IntentIntegrator;
import com.google.zxing.integration.android.IntentResult;

public class MainActivity extends AppCompatActivity {

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

        // 初始化扫描器
        IntentIntegrator integrator = new IntentIntegrator(this);
        integrator.setDesiredBarcodeFormats(IntentIntegrator.ALL_CODE_TYPES);
        integrator.setPrompt("Scan a barcode or QR code");
        integrator.setCameraId(0);  // 使用后置摄像头
        integrator.initiateScan();
    }

    // 处理扫描结果
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
        if (result != null) {
            if (result.getContents() == null) {
                // 扫描取消
            } else {
                // 获取扫描结果
                String scannedData = result.getContents();
                // 处理扫描结果
            }
        } else {
            super.onActivityResult(requestCode, resultCode, data);
        }
    }
}