Question

我正在开发一个带有嵌入式QR码阅读器的应用程序，在扫描了代码之后，我必须使用从qrcode提取的参数来启动另一个活动（名为CodaActivity.class）。

我从此处的教程开始：（https://www.androidtutorialonline.com/android-qr-code-scanner/）然后我尝试根据自己的需要对其进行自定义。

这是QRCodeScannerActivity的代码：

import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.Toast;

import com.google.zxing.Result;
import me.dm7.barcodescanner.zxing.ZXingScannerView;
import static android.Manifest.permission.CAMERA;

public class QrCodeScannerActivity extends AppCompatActivity implements ZXingScannerView.ResultHandler {
    private static final int REQUEST_CAMERA = 1;
    private ZXingScannerView mScannerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mScannerView = new ZXingScannerView(this);
        setContentView(mScannerView);
        int currentapiVersion = android.os.Build.VERSION.SDK_INT;
        if (currentapiVersion >= android.os.Build.VERSION_CODES.M) {
            if (checkPermission()) {
                Toast.makeText(getApplicationContext(), "Permission already granted", Toast.LENGTH_LONG).show();

            } else {
                requestPermission();
            }
        }

    }

    private boolean checkPermission() {
        return ( ContextCompat.checkSelfPermission(getApplicationContext(), CAMERA ) == PackageManager.PERMISSION_GRANTED);
    }

    private void requestPermission() {
        ActivityCompat.requestPermissions(this, new String[]{CAMERA}, REQUEST_CAMERA);
    }

    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case REQUEST_CAMERA:
                if (grantResults.length > 0) {

                    boolean cameraAccepted = grantResults[0] == PackageManager.PERMISSION_GRANTED;
                    if (cameraAccepted){
                        Toast.makeText(getApplicationContext(), "Permission Granted, Now you can access camera", Toast.LENGTH_LONG).show();
                    }else {
                        Toast.makeText(getApplicationContext(), "Permission Denied, You cannot access and camera", Toast.LENGTH_LONG).show();
                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                            if (shouldShowRequestPermissionRationale(CAMERA)) {
                                showMessageOKCancel("You need to allow access to both the permissions",
                                        new DialogInterface.OnClickListener() {
                                            @Override
                                            public void onClick(DialogInterface dialog, int which) {
                                                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                                                    requestPermissions(new String[]{CAMERA},
                                                            REQUEST_CAMERA);
                                                }
                                            }
                                        });
                                return;
                            }
                        }
                    }
                }
                break;
        }
    }

    private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
        new android.support.v7.app.AlertDialog.Builder(QrCodeScannerActivity.this)
                .setMessage(message)
                .setPositiveButton("OK", okListener)
                .setNegativeButton("Cancel", null)
                .create()
                .show();
    }

    @Override
    public void onResume() {
        super.onResume();

        int currentapiVersion = android.os.Build.VERSION.SDK_INT;
        if (currentapiVersion >= android.os.Build.VERSION_CODES.M) {
            if (checkPermission()) {
                if(mScannerView == null) {
                    mScannerView = new ZXingScannerView(this);
                    setContentView(mScannerView);
                }
                mScannerView.setResultHandler(this);
                mScannerView.startCamera();
            } else {
                requestPermission();
            }
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mScannerView.stopCamera();
    }
    @Override
    public void handleResult(Result rawResult) {

        final String testoLink = rawResult.getText();
        String[] risultato = testoLink.split(":");
        risultato[1] = risultato[1].trim();
        Log.e("QRCodeScanner", rawResult.getText());
        Intent intent = new Intent(QrCodeScannerActivity.this, CodaActivity.class);
        Bundle b = new Bundle();
        b.putString("medico", risultato[1]);
        intent.putExtras(b); 
        startActivity(intent);
        finish();

    }


}

但是，当我扫描QR码（当然是使用物理设备）后，调试器退出并显示以下消息：

I/art: Object allocation is busy now, so prior to grow the heap. New heap size is 33 MB
I/art: current process_level is : 0
I/art: current process_level is : 0
I/art: current process_level is : 0
I/art: current process_level is : 0
I/art: current process_level is : 0
I/Process: Sending signal. PID: 8310 SIG: 9
Application terminated.

手机中的应用仍保持运行状态，但执行其他活动。为什么？以及为什么我没有错误！感谢您的回答

Answer 1

经过多次尝试，并在另一部带奥利奥（Oreo）的电话上，我终于发现我在分割字符串时犯了一个错误，令牌是错误的，但是在先前的电话中没有异常，因此我无法弄清楚这个证据。并更好地观看代码，比起startActivity（）调用，我将finish（）语句放在前面。

希望这可以帮助某人。

Answer 2

我希望这可以帮助某人，我需要更多时间来找出它您应该使用正确的版本：^1.0.1 并将其添加到 pupspec.yaml 中，如下所示：

dependencies:
  flutter:
    sdk: flutter

  flutter_barcode_scanner: ^1.0.1

正在发送信号。 PID：6939 SIG：9具有zxing QR码扫描仪

2 个答案: