Question

我有两个包含整数价格的QR码。我想扫描每个qr代码并将其价格加到总金额中。这是MainActivity.java 例如。如果我扫描包含价格40的qr代码，则会在TextView2中显示40。如何添加n个qr代码并在每次扫描qrcode时更新总数？

package com.mycompany.smartshoppingcart;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.ActivityNotFoundException;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

private static final int ACTIVITY_RESULT_QR_DRDROID = 0;

TextView report;
Button scan;

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

    report = (TextView) findViewById(R.id.textView2);
    scan = (Button) findViewById(R.id.button1);

    scan.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub

            Intent i = new Intent("la.droid.qr.scan");

            try {

                startActivityForResult(i, ACTIVITY_RESULT_QR_DRDROID);
            }
            catch (ActivityNotFoundException activity) {

                MainActivity.qrDroidRequired(MainActivity.this);
            }
        }
    });
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);

    if( ACTIVITY_RESULT_QR_DRDROID == requestCode
            && data != null && data.getExtras() != null ) {

        String result = data.getExtras().getString("la.droid.qr.result");



      report.setText(result);
        report.setVisibility(View.VISIBLE);
    }
}

/*
 *
 * If we don't have QRDroid Application in our Device,
 * It will call below method (qrDroidRequired)
 *
 */

protected static void qrDroidRequired(final MainActivity activity) {
    // TODO Auto-generated method stub

    AlertDialog.Builder AlertBox = new AlertDialog.Builder(activity);

    AlertBox.setMessage("QRDroid Missing");

    AlertBox.setPositiveButton("Direct Download", new OnClickListener() {

        @Override
        public void onClick(DialogInterface arg0, int arg1) {
            // TODO Auto-generated method stub

            activity.startActivity(new Intent(Intent.ACTION_VIEW,
                    Uri.parse("http://droid.la/apk/qr/")));
        }
    });

    AlertBox.setNeutralButton("From Market", new OnClickListener() {

        @Override
        public void onClick(DialogInterface dialog, int which) {
            // TODO Auto-generated method stub

            activity.startActivity(new Intent(Intent.ACTION_VIEW,
                    Uri.parse("http://market.android.com/details?id=la.droid.qr")));
        }
    });

    AlertBox.setNegativeButton("Cancel", new OnClickListener() {

        @Override
        public void onClick(DialogInterface dialog, int which) {
            // TODO Auto-generated method stub

            dialog.cancel();
        }
    });

    AlertBox.create().show();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);


    return true;
}

}

Answer 1

您应该将此值存储在类的全局变量中。

在课程顶部添加int totalCost = 0;（Button scan;行以下）

然后在onActivityResult中，一旦从qrcode返回结果，就应该将此变量转换为整数

通过int cost = Integer.parseInt(result);

获得成本的整数值后，只需将其添加到总费用

即可

totalCost += cost;

然后更新文本标签

report.setText("" + totalCost);

如何扫描多个QR码并获得添加？

1 个答案: