QXmlstreamreader麻煩

Question

我想讀取XML標記內的文本。我正在使用readelementtext（）函數，但它返回一個空的Qstring。我使用的代碼如下：

#include <QCoreApplication> 
#include <QFile> 
#include <QStringList> 
#include <QTextStream> 
#include <QXmlStreamReader> 
#include <QXmlStreamWriter> 
#include <QByteArray> 
#include <iostream> 
#include <ostream> 
#include <QString> 

class XmlStreamLint 
{ 
public: 
    Q_DECLARE_TR_FUNCTIONS(XmlStreamLint) 
}; 

int main(int argc, char *argv[]) 
{ 
    enum ExitCode 
    { 
     Success, 
     ParseFailure, 
     ArgumentError, 
     WriteError, 
     FileFailure 
    }; 

    QCoreApplication app(argc, argv); 

    QTextStream errorStream(stderr); 

    if (argc != 2) 
    { 
     errorStream << XmlStreamLint::tr(
         "Usage: xmlstreamlint <path to XML file>\n"); 
     return ArgumentError; 
    } 

    QString inputFilePath(QCoreApplication::arguments().at(1)); 
    QFile inputFile(inputFilePath); 

    if (!QFile::exists(inputFilePath)) 
    { 
     errorStream << XmlStreamLint::tr(
         "File %1 does not exist.\n").arg(inputFilePath); 
     return FileFailure; 

    } else if (!inputFile.open(QIODevice::ReadOnly|QIODevice::Text)) { 
     errorStream << XmlStreamLint::tr(
         "Failed to open file %1.\n").arg(inputFilePath); 
     return FileFailure; 
    } 
    QString outputfilepath="/home/shakeel/xmlstreamlint/testing.xml"; 
    QFile outputFile(outputfilepath); 
    //QFile outputFile; 
    if (!outputFile.open(stdout, QIODevice::WriteOnly)) 
    { 
     errorStream << XmlStreamLint::tr("Failed to open stdout."); 
     return WriteError; 
    } 
    QByteArray array[20000]; 
    QByteArray *ptr; 
    ptr=&array[0]; 
    QXmlStreamReader reader(&inputFile); 
    //QXmlStreamWriter writer(&outputFile); 
    QXmlStreamWriter writer(ptr); 
    QString text,signal; 
    int count=0; 
    while (!reader.atEnd()) 
    { 
     reader.readNext(); 

     if (reader.error()) 
     { 
      errorStream << XmlStreamLint::tr(
          "Error: %1 in file %2 at line %3, column %4.\n").arg(
           reader.errorString(), inputFilePath, 
           QString::number(reader.lineNumber()), 
           QString::number(reader.columnNumber())); 
      return ParseFailure; 

     } else 
      if (reader.isStartElement()) 
      { 
       text = reader.name().toString(); 
       if(text.operator ==("TYPICAL_CYCLE_CHANNEL")) 
       { 
          count=count+1; 
          signal=reader.readElementText(); 
          writer.writeCurrentToken(reader); 

我想讀的是如下的XML;

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE ECG SYSTEM "mortara.dtd"> 
<!-- Generated by Mortara ELI Link 2.20 --> 
<!-- Mortara Instrument, Inc. --> 
<!-- Server Name - Unknown --> 
    <ECG 
    ACQUISITION_TIME="20070227033111" 
    ROOM="" 
    LOCATION="" 
    COMMENT="" 
    AGE="59" 
    AGE_UNITS="Y" 
    HEIGHT="" 
    HEIGHT_UNITS="I" 
    WEIGHT="" 
    WEIGHT_UNITS="L" 
    NUM_QRS="10" 
    AVERAGE_RR="935" 
    VENT_RATE="64" 
    SEQUENCE_NUMBER="6" 
    > 
    <DEMOGRAPHIC_FIELD ID="1" LABEL="Name:" VALUE="Asd" UNITS="" /> 
    <DEMOGRAPHIC_FIELD ID="7" LABEL="FName:&amp;," VALUE="We" UNITS="" /> 
    <DEMOGRAPHIC_FIELD ID="2" LABEL="ID&amp;ID:" VALUE="12" UNITS="" /> 
    <DEMOGRAPHIC_FIELD ID="16" LABEL="DOB:" VALUE="12/13/47" UNITS="" /> 
    <DEMOGRAPHIC_FIELD ID="3" LABEL="Age&amp;yr" VALUE="59" UNITS="Y" /> 
    <DEMOGRAPHIC_FIELD ID="4" LABEL="Sex" VALUE="Male" UNITS="" /> 
    <SITE 
    ID="0" 
    /> 
    <SUBJECT 
    LAST_NAME="Asd" 
    FIRST_NAME="We" 
    GENDER="Male" 
    ID="12" 
    /> 
    <SOURCE 
    TYPE="RESTING" 
    MANUFACTURER="Mortara Instrument, Inc." 
    MANUFACTURER_ID="10" 
    MODEL="el250" 
    ID="4" 
    TRANSMISSION_TIME="20070414092347" 
    /> 
    <AUTOMATIC_INTERPRETATION> 
     <STATEMENT 
     STATEMENT_NUMBER="1" 
     TEXT="SINUS RHYTHM WITH SHORT PR INTERVAL" 
     REASON="" 
     /> 
     <STATEMENT 
     STATEMENT_NUMBER="2" 
     TEXT="TYPE A WOLFF-PARKINSON-WHITE PATTERN" 
     REASON="" 
     /> 
     <STATEMENT 
     STATEMENT_NUMBER="3" 
     TEXT="NO FURTHER INTERPRETATION POSSIBLE" 
     REASON="" 
     /> 
     <STATEMENT 
     STATEMENT_NUMBER="4" 
     TEXT="ATYPICAL ECG" 
     REASON="" 
     /> 
     <STATEMENT 
     STATEMENT_NUMBER="5" 
     TEXT="" 
     REASON="" 
     /> 
     <STATEMENT 
     STATEMENT_NUMBER="6" 
     TEXT="UNCONFIRMED REPORT" 
     REASON="" 
     /> 
    </AUTOMATIC_INTERPRETATION> 
    <TYPICAL_CYCLE 
    R_PEAK="500" 
    P_ONSET="-185" 
    P_OFFSET="-116" 
    Q_ONSET="-87" 
    Q_OFFSET="75" 
    T_OFFSET="369" 
    P_DURATION="69" 
    PR_DURATION="98" 
    QRS_DURATION="162" 
    QT="456" 
    QTC="465" 
    QTCB="471" 
    QTCF="466" 
    P_AXIS="17" 
    QRS_AXIS="-54" 
    T_AXIS="108" 
    BITS="16" 
    FORMAT="SIGNED" 
    UNITS_PER_MV="400" 
    DURATION="1200" 
    SAMPLE_FREQ="1000" 
    ENCODING="BASE64" 
    > 
    <TYPICAL_CYCLE_CHANNEL 
    NAME="I" 
    DATA="BQAAAP7/AAAAAP7/AAACAAIAAgAAAP7//v/+/wAA/v8AAAIAAAAAAAIA/v/+ 
/wAAAAAAAAAAAAD+/wAAAAD7//v/AgACAAAA/v/+//v/+f/5//v/+f/7/wAA 
AgACAP7/+//5//b/9P/0/wAA+/8AAAAA/v/7//T/8f/5//n//v/7//7/AgAA 
AP7/AAD5//n//v/5//v/AAD7//n/AAAAAPv/+//7//7//v/5//v/+f/5//v/ 
+f/5//v/AAD7//n/+f/5//n/9v/2//T/+f/5//v/9v/+//n/+f/5//n/+f/+ 
//n/+f/5//n//v8AAPv/+f/7//n/+f/2//T//v/5//b/9v/0//v//v/5//b/ 
9v/0//T/9P/x//H/9P/7//7//v/2//n/+//5//n/9P/5//n/+//x//T/7//0 
//b/8f/2//n/+//7/wAA9v/2//H/9P/0//T/7//x//n/9v/7/wAA+//5//b/ 
9v/2//b/9v/v//H/9v/0//n/+f/2//T/7//x//b/9v/0//b/+f/x//H/8f/0 
//T/8f/5//n/9v/5//n/9v/2//b/+f/2//b/9v/+//n/9P/s//H/9P/2//H/ 
7//x//b/9v/0//T/9v/5//b/9P/2//T/+//+//H/7P/q/+//9P/v//H/9v/x 
//H/9P/0//b/9v/5//T/+f/2//v/+//2//T/9P/2//b/9v/x//T/9v/2//H/ 
9P/5//b/8f/0//T/9v/0//H/7P/s/+z/9P/5//v/9v/5//b/9P/x/+//9v/x 
//T/9v/2//T/9v/2//T/9P/0/+//8f/x//b/9P/x/+//8f/0//T/+f/+//v/ 
9v/0//v/AAD7//T/9v/5//v/+f/+/wIAAAD7//n//v/7/wIAAgAAAP7/AAAH 
AAUAAAACAAcABwAUAAwAAgAAAP7/AAAKAAIABwAFAAcACgAPAAoADAARAAwA 
CgAKAAwACgARAAwAEQARAA8ACgAKAAoACgARAAoACgAFAAcABwAAAAIABwAK 
AAcABwAHAAUAAgAFAAIAAgAFAAUACgAKAAwACgAKAAwABwAFAAIABQACAAIA 
AgAHAAIAAAAAAAAA+//7/wAA/v/+//7/AAAFAAAAAAAFAAIABQAKAAoAFAAW 
ABkAGwAeACAAKAAtADQAPABDAE0AVQBQAFIAVQBVAFoAVwBSAFoAYQBkAGQA 
ZABrAHAAbgBwAHMAdQB6AIIAhwCMAI4AlgCgAKUArACxALkAuwDAAMgAzQDU 
ANwA3ADmAOsA9QD8AAEBAQEJARUBIgEsATsBRwFRAWABcgGBAZUBrgG/Ac4B 
7AEAAhkCKwI3AksCXQJkAmwCbgJuAnYCewJ2AnMCbgJpAmcCXQJVAkYCPAIr 
Ag8C9gHlAdsBxwGwAZoBgQFoAVEBQAEpARgBBgH3AOMAzQC5AKoAnQCMAHoA 
ZABXAEgAQQA5AC0ALQAlACAAIAAbABsAFgAWAAIAAgAAAAcAAgD5//H/9P/x 
//H/9v/v//b/8f/v/+z/6v/s//H/9v/0//H/6v/0//T/8f/v/+r/7P/s/+f/ 
5f/q/+r/7P/q/+r/5//q/+//7P/l/+X/5f/q/+X/2//g/+X/5//l/+L/4P/g 
/+r/7P/s/+f/5f/l/+X/5f/l/+f/6v/l/+X/5f/q/+z/6v/s/+r/5//n/+X/ 
3f/i/+D/5f/l/+X/5f/n/+f/4P/g/+D/5f/l/+L/5f/l/+X/5f/l/+L/4v/i 
/+X/4v/n/+L/5f/n/+X/4P/g/+X/5f/g/+L/5f/i/+L/3f/g/93/4P/l/+X/ 
3f/g/+D/3f/g/+D/4P/l/+f/5f/g/+X/4v/g/9v/2//b/+L/5f/i/9v/2//d 
/93/3f/b/9 

Answer 1

Dave 讓我重新發布代碼和示例xml。我已經刪除了錯誤捕獲條件。

QString inputFilePath(QCoreApplication::arguments().at(1)); 
QFile inputFile(inputFilePath); 
QString outputfilepath="/home/shakeel/xmlstreamlint/testing.xml"; 
QFile outputFile(outputfilepath); 
QByteArray array[2000]; 
QByteArray *ptr; 
ptr=&array[0]; 
QXmlStreamReader reader(&inputFile); 
QXmlStreamWriter writer(ptr); 
QString text,signal; 
while (!reader.atEnd()) 
{ 
    reader.readNext(); 
    } else 
     if (reader.isStartElement()) 
     { 
      text = reader.name().toString(); 
      if(text.operator ==("TYPICAL_CYCLE_CHANNEL")) 
      { 
      signal=reader.readElementtext(); 
      } 
     } 
     writer.writeCurrentToken(reader);  

}

Answer 2

只需添加結束括號的XML完成 看看這有助於 問候