启动外部活动以扫描条形码

Start an external activity to scan barcode

本文关键字：扫描 条形码 活动 外部 启动      更新时间：2023-10-16

我想从我的应用程序启动条形码扫描仪并获取标签

这是我到目前为止所拥有的：

扫描.h

class DecodeBarCode : public QObject
{
    Q_OBJECT
    BarCodeReceiver *m_receiver;
public:
    explicit DecodeBarCode(QObject *parent = 0);
    ~DecodeBarCode();
    Q_INVOKABLE void useZXingApp();
signals:
    void tagFound(QString tag);
};
class BarCodeReceiver : public QAndroidActivityResultReceiver
{
    DecodeBarCode *m_decoder;
public:
    BarCodeReceiver(DecodeBarCode *decoder) : m_decoder(decoder) {}
    virtual void handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data) {
        emit m_decoder->tagFound("Receiver worked");
    }
};

扫描.cpp

DecodeBarCode::DecodeBarCode(QObject *parent) : QObject(parent)
{
    m_receiver = new BarCodeReceiver(this);
}
DecodeBarCode::~DecodeBarCode()
{
    delete m_receiver;
}
void DecodeBarCode::useZXingApp()
{
    QAndroidJniObject intent = QAndroidJniObject::fromString("com/google/zxing/client/android/SCAN");
    if (intent.isValid()) {
        QtAndroid::startActivity(intent,0,m_receiver); // CRASH HERE
    } else {
        emit tagFound("Invalid"); // TEMP
    }
}

那是我第一次使用JNI，从未在java或c ++/Qt中使用过它

。

一定有什么很不对劲的地方，是什么？

这是我使用 tent 从应用程序共享文本的示例：

void Sharer::share(const QString &content)
 {
     qDebug() << "sharing text: " << content;
 #ifdef Q_OS_ANDROID
     auto ACTION_SEND = QAndroidJniObject::getStaticObjectField("android/content/Intent", "ACTION_SEND", "Ljava/lang/String;");
     auto EXTRA_TEXT = QAndroidJniObject::getStaticObjectField("android/content/Intent", "EXTRA_TEXT", "Ljava/lang/String;");
     auto intent = QAndroidJniObject("android/content/Intent", "(Ljava/lang/String;)V", ACTION_SEND.object());
     // Intent  Intent.putExtra(String name, String value)
     intent.callObjectMethod("putExtra", "(Ljava/lang/String;Ljava/lang/String;)Landroid/content/Intent;", EXTRA_TEXT.object(), QAndroidJniObject::fromString(content).object());
     // Intent  Intent.setType(String type)
     intent.callObjectMethod("setType", "(Ljava/lang/String;)Landroid/content/Intent;", QAndroidJniObject::fromString(QString("text/plain")).object());
     qDebug() << intent.toString();
     // static Intent Intent.createChooser(Intent target, CharSequence title)
     auto chooserIntent = QAndroidJniObject::callStaticObjectMethod("android/content/Intent", "createChooser", "(Landroid/content/Intent;Ljava/lang/CharSequence;)Landroid/content/Intent;", intent.object(), QAndroidJniObject::fromString(QString("It's Time To Choose...")).object());
     qDebug() << chooserIntent.toString();
     QtAndroid::startActivity(chooserIntent, 0, nullptr);
 #endif
 }

如您所见，您需要自己创建意图，检索所有需要的对象。

我终于让它工作了，这是完整的代码：

解码条形码.h

#ifndef DECODEBARCODE_H
#define DECODEBARCODE_H
#include <QObject>
#ifdef Q_OS_ANDROID
#include <QtAndroidExtras/QtAndroid>
#include <QtAndroidExtras/QAndroidJniObject>
#include <QtAndroidExtras/QAndroidJniEnvironment>
#include <QtAndroidExtras/QAndroidActivityResultReceiver>
#endif
class BarCodeReceiver;
class DecodeBarCode : public QObject
{
    Q_OBJECT
    BarCodeReceiver *m_receiver;
public:
    explicit DecodeBarCode(QObject *parent = 0);
    ~DecodeBarCode();
    Q_INVOKABLE void useZXingApp();
signals:
    void tagFound(QString tag);
};
#ifdef Q_OS_ANDROID
class BarCodeReceiver : public QAndroidActivityResultReceiver
{
    DecodeBarCode *m_decoder;
public:
    BarCodeReceiver(DecodeBarCode *decoder);
    virtual void handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data);
};
#else
class BarCodeReceiver
{
public:
    BarCodeReceiver(DecodeBarCode *decoder) {Q_UNUSED(decoder)};
};
#endif
#endif // DECODEBARCODE_H

解码条形码.cpp

#include "decodebarcode.h"
DecodeBarCode::DecodeBarCode(QObject *parent) : QObject(parent)
{
    m_receiver = new BarCodeReceiver(this);
}
DecodeBarCode::~DecodeBarCode()
{
    delete m_receiver;
}
void DecodeBarCode::useZXingApp()
{
#ifdef Q_OS_ANDROID
    QAndroidJniObject action = QAndroidJniObject::fromString("com.google.zxing.client.android.SCAN");
    // Intent intent = new Intent(action)
    QAndroidJniObject intent("android/content/Intent","(Ljava/lang/String;)V", action.object<jstring>());
    jint flagCategorieDefault = QAndroidJniObject::getStaticField<jint>("android/content/Intent", "CATEGORY_DEFAULT");
    jint flagActivityClearTop = QAndroidJniObject::getStaticField<jint>("android/content/Intent", "FLAG_ACTIVITY_CLEAR_TOP");
    jint flagActivityClearTaskReset = QAndroidJniObject::getStaticField<jint>("android/content/Intent", "FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET");
    // intentScan.addCategory(Intent.CATEGORY_DEFAULT);
    intent.callObjectMethod("addCategory", "(I)V", flagCategorieDefault);
    //intentScan.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intent.callObjectMethod("addFlags", "(I)V", flagActivityClearTop);
    //intentScan.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
    intent.callObjectMethod("addFlags", "(I)V", flagActivityClearTaskReset);
    QtAndroid::startActivity(intent, 0, m_receiver);
#endif
}

#ifdef Q_OS_ANDROID
BarCodeReceiver::BarCodeReceiver(DecodeBarCode *decoder)
    : m_decoder(decoder)
{
}
void BarCodeReceiver::handleActivityResult(int receiverRequestCode, int resultCode, const QAndroidJniObject &data)
{
    QAndroidJniObject stringExtraScanResult = QAndroidJniObject::fromString("SCAN_RESULT");
    QAndroidJniObject scanResult = data.callObjectMethod("getStringExtra", "(Ljava/lang/String;)Ljava/lang/String;", stringExtraScanResult.object<jstring>());
    emit m_decoder->tagFound(scanResult.toString());
}
#endif

如果您有同样的问题，我希望对您有所帮助

使用此库来挽救您的生命:)https://github.com/zxing/zxing

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