如何构建可扫描二维码并在 Android 上使用其数据的应用程序？

Question

请注意，我在 Android 开发方面完全是个新手，只进步到 "Hello world"。

我实际上并不想构建二维码扫描仪，我宁愿使用第三方组件，但我需要一个可以扫描二维码、显示代码中的一些数据并发送一些数据的应用程序到网络服务。

有人可以给我一个关于你应该在我的应用程序中使用的过程和结构的真正的初学者大纲。我是一位经验丰富的 C# 开发人员，所以实际的 Java 编码不会有问题，我当然不是在问如何做到这一点，我只是在问如何设置基本的应用程序架构和流程，例如如何显示对话、联系 Web 服务以及使用第三方组件。

我需要扫描二维码，从中提取一些文本代码，将这些代码发送到网络服务。

Answer 1

ZXing is a pretty good library which you can integrate in your application.Refer this class CaptureActivity

Answer 2

首先您需要 zxing library for creating QR Codes and an installed application for reading QR codes like BarcodeScanner 和一个编码器 class，例如：

import java.util.Collection;
import java.util.HashSet;
import java.util.Hashtable;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.telephony.PhoneNumberUtils;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.ByteMatrix;

public final class QRCodeEncoder {
    private static final int WHITE = 0xFFFFFFFF;
    private static final int BLACK = 0xFF000000;

private int dimension = Integer.MIN_VALUE;
private String contents = null;
private String displayContents = null;
private String title = null;
private BarcodeFormat format = null;
private boolean encoded = false;

public QRCodeEncoder(String data, Bundle bundle, String type, String format, int dimension) {
    this.dimension = dimension;
    encoded = encodeContents(data, bundle, type, format);
}

public String getContents() {
    return contents;
}

public String getDisplayContents() {
    return displayContents;
}

public String getTitle() {
    return title;
}

private boolean encodeContents(String data, Bundle bundle, String type, String formatString) {
    // Default to QR_CODE if no format given.
    format = null;
    if (formatString != null) {
        try {
            format = BarcodeFormat.valueOf(formatString);
        } catch (IllegalArgumentException iae) {
            // Ignore it then
        }
    }
    if (format == null || format == BarcodeFormat.QR_CODE) {
        this.format = BarcodeFormat.QR_CODE;
        encodeQRCodeContents(data, bundle, type);
    } else if (data != null && data.length() > 0) {
        contents = data;
        displayContents = data;
        title = "Text";
    }
    return contents != null && contents.length() > 0;
}

private void encodeQRCodeContents(String data, Bundle bundle, String type) {
    if (type.equals(Contents.Type.TEXT)) {
        if (data != null && data.length() > 0) {
            contents = data;
            displayContents = data;
            title = "Text";
        }
    } else if (type.equals(Contents.Type.EMAIL)) {
        data = trim(data);
        if (data != null) {
            contents = "mailto:" + data;
            displayContents = data;
            title = "E-Mail";
        }
    } else if (type.equals(Contents.Type.PHONE)) {
        data = trim(data);
        if (data != null) {
            contents = "tel:" + data;
            displayContents = PhoneNumberUtils.formatNumber(data);
            title = "Phone";
        }
    } else if (type.equals(Contents.Type.SMS)) {
        data = trim(data);
        if (data != null) {
            contents = "sms:" + data;
            displayContents = PhoneNumberUtils.formatNumber(data);
            title = "SMS";
        }
    } else if (type.equals(Contents.Type.CONTACT)) {
        if (bundle != null) {
            StringBuilder newContents = new StringBuilder(100);
            StringBuilder newDisplayContents = new StringBuilder(100);

            newContents.append("MECARD:");

            String name = trim(bundle.getString(ContactsContract.Intents.Insert.NAME));
            if (name != null) {
                newContents.append("N:").append(escapeMECARD(name)).append(';');
                newDisplayContents.append(name);
            }

            String address = trim(bundle.getString(ContactsContract.Intents.Insert.POSTAL));
            if (address != null) {
                newContents.append("ADR:").append(escapeMECARD(address)).append(';');
                newDisplayContents.append('\n').append(address);
            }

            Collection<String> uniquePhones = new HashSet<String>(Contents.PHONE_KEYS.length);
            for (int x = 0; x < Contents.PHONE_KEYS.length; x++) {
                String phone = trim(bundle.getString(Contents.PHONE_KEYS[x]));
                if (phone != null) {
                    uniquePhones.add(phone);
                }
            }
            for (String phone : uniquePhones) {
                newContents.append("TEL:").append(escapeMECARD(phone)).append(';');
                newDisplayContents.append('\n').append(PhoneNumberUtils.formatNumber(phone));
            }

            Collection<String> uniqueEmails = new HashSet<String>(Contents.EMAIL_KEYS.length);
            for (int x = 0; x < Contents.EMAIL_KEYS.length; x++) {
                String email = trim(bundle.getString(Contents.EMAIL_KEYS[x]));
                if (email != null) {
                    uniqueEmails.add(email);
                }
            }
            for (String email : uniqueEmails) {
                newContents.append("EMAIL:").append(escapeMECARD(email)).append(';');
                newDisplayContents.append('\n').append(email);
            }

            String url = trim(bundle.getString(Contents.URL_KEY));
            if (url != null) {
                // escapeMECARD(url) -> wrong escape e.g. http\://zxing.google.com
                newContents.append("URL:").append(url).append(';');
                newDisplayContents.append('\n').append(url);
            }

            String note = trim(bundle.getString(Contents.NOTE_KEY));
            if (note != null) {
                newContents.append("NOTE:").append(escapeMECARD(note)).append(';');
                newDisplayContents.append('\n').append(note);
            }

            // Make sure we've encoded at least one field.
            if (newDisplayContents.length() > 0) {
                newContents.append(';');
                contents = newContents.toString();
                displayContents = newDisplayContents.toString();
                title = "Contact";
            } else {
                contents = null;
                displayContents = null;
            }

        }
    } else if (type.equals(Contents.Type.LOCATION)) {
        if (bundle != null) {
            // These must use Bundle.getFloat(), not getDouble(), it's part of the API.
            float latitude = bundle.getFloat("LAT", Float.MAX_VALUE);
            float longitude = bundle.getFloat("LONG", Float.MAX_VALUE);
            if (latitude != Float.MAX_VALUE && longitude != Float.MAX_VALUE) {
                contents = "geo:" + latitude + ',' + longitude;
                displayContents = latitude + "," + longitude;
                title = "Location";
            }
        }
    }
}

public Bitmap encodeAsBitmap() throws WriterException {
    if (!encoded) return null;

    Hashtable hints = null;
    String encoding = guessAppropriateEncoding(contents);
    if (encoding != null) {
    hints = new Hashtable();
    hints.put(EncodeHintType.CHARACTER_SET, encoding);
    }
    MultiFormatWriter writer = new MultiFormatWriter();
    ByteMatrix result =writer.encode(contents, format, dimension, dimension, hints);
    int width = result.getWidth();
    int height =result.getHeight();
    int[] pixels = new int[width * height];
    // All are 0, or black, by default
    for (int y = 0; y < height; y++) {
    int offset = y * width;
    for (int x = 0; x < width; x++) {

    if(result.get(x, y)== 0)
    {
    pixels[offset + x] = BLACK ;
    }
    else
    pixels[offset + x] = WHITE ;

    }
    }

    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
    return bitmap;
    }

private static String guessAppropriateEncoding(CharSequence contents) {
    // Very crude at the moment
    for (int i = 0; i < contents.length(); i++) {
        if (contents.charAt(i) > 0xFF) { return "UTF-8"; }
    }
    return null;
}

private static String trim(String s) {
    if (s == null) { return null; }
    String result = s.trim();
    return result.length() == 0 ? null : result;
}

private static String escapeMECARD(String input) {
    if (input == null || (input.indexOf(':') < 0 && input.indexOf(';') < 0)) { return input; }
    int length = input.length();
    StringBuilder result = new StringBuilder(length);
    for (int i = 0; i < length; i++) {
        char c = input.charAt(i);
        if (c == ':' || c == ';') {
            result.append('\');
        }
        result.append(c);
    }
    return result.toString();
}
}

希望对您有所帮助:)

Answer 3

你也可以考虑使用manateework sdk，速度非常快，性价比高。我有可用于支持不同平台的移动应用程序的 SDK，即。 iOS、Android 等和代码符号。 PL。有关此 sdk 的更多详细信息，请参阅 https://manateeworks.com/

如何构建可扫描二维码并在 Android 上使用其数据的应用程序？

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