Qt日常备注(函数/接口实现)

1.判断QString是否为纯数字

2.查找自身最长重复子字符串

3.树形列表复选框操作

4.更改文件权限

5.判断系统64位

6.文件生成md5值

7.版本号比较(字符串比较)

//-----实现-----

1.判断QString是否为纯数字

bool IsDigitString(QString strSource)
{
    bool bDigit = false;

    if (strSource.isEmpty())
    {
        return bDigit;
    }

    QByteArray strByteArray = strSource.toLatin1();
    const char *chString = strByteArray.data();

    while (*chString && *chString>='0' && *chString<='9') chString++;

    if (*chString)
    {
        bDigit = false;
    }
    else
    {
        bDigit = true;
    }

    return bDigit;
}

2.查找自身最长重复子字符串

QString MaxSubString(QString inputString)
{
    QString subString = "";
    int strLen = inputString.size();

    if  (strLen  <=  0)
    {
        return subString;
    }

    int maxSubStrLen = 0;
    int tempLen = 0;
    int subIndex = 0;
    int i = 0;
    int j = 0;
    int k = 0;

    while (i <  strLen)
    {
        j = i+1;    
        while(j < strLen)
        {
            if  (inputString.at(i)  ==  inputString.at(j))
            {
                tempLen = 1;
                for (k=1;  j+k<strLen && inputString.at(i+k)==inputString.at(j+k);  k++)
                {
                    tempLen++;
                }

                if  (tempLen  >  maxSubStrLen)
                {
                    subIndex = i;
                    maxSubStrLen = tempLen;
                }

                j += tempLen;
            }
            else
            {
                   j++;
            }
        }
        i++;
    }

    for  (i=0;  i<maxSubStrLen;  i++)
    {
        subString.append(inputString.at(subIndex+i));
    }

    return subString;    
}

 3.树形列表复选框操作

void CCheckBoxDialog::treeItemsChangeStol(QTreeWidgetItem *pCurrentItem, int)
{    
    if (m_itemsCount <= 0)//没有子节点,不存在选中操作
    {
        updateComboInfoStol();
        return;
    }

    if (Qt::Checked == pCurrentItem->checkState(0))
    {
        //QTreeWidgetItem *parentItem = pCurrentItem->parent();

        int childCount = pCurrentItem->childCount();
        if (childCount >0)//父节点被选中
        {
            for (int i=0; i<childCount; i++)
            {
                pCurrentItem->child(i)->setCheckState(0, Qt::Checked);
            }
        }
        else    //更新父节点复选框状态
        {
            updateParentItemStateStol(pCurrentItem);
        }
    }
    else if (Qt::Unchecked == pCurrentItem->checkState(0))
    {
        //QTreeWidgetItem *parentItem = pCurrentItem->parent();

        int childCount = pCurrentItem->childCount();
        if (childCount >0)//父节点被选中
        {
            for (int i=0; i<childCount; i++)
            {
                pCurrentItem->child(i)->setCheckState(0, Qt::Unchecked);
            }
        }
        else    //更新父节点复选框状态
        {
            updateParentItemStateStol(pCurrentItem);
        }
    }
    updateComboInfoStol();
}
void CCheckBoxDialog::updateParentItemStateStol(QTreeWidgetItem *pCurrentItem)
{
    QTreeWidgetItem *parentItem = pCurrentItem->parent();
    if (parentItem == NULL)
    {
        return;
    }

    int selectedCount = 0;//当前子节点选中个数
    int childCount = parentItem->childCount();
    for (int i=0; i<childCount; i++)
    {
        QTreeWidgetItem *childItem = parentItem->child(i);
        if (Qt::Checked == childItem->checkState(0))
        {
            selectedCount++;
        }
    }

    if (selectedCount <= 0)
    {
        //未选中任何项
        parentItem->setCheckState(0, Qt::Unchecked);
    }
    else if (selectedCount>0 && selectedCount<childCount)
    {
        //选中部分子项
        parentItem->setCheckState(0, Qt::PartiallyChecked);
    }
    else if (selectedCount == childCount)
    {
        //选中所有子项
        parentItem->setCheckState(0, Qt::Checked);
    }
}

 4.更改文件权限

static void ChangeFilePermission( const QString &filePath )
{
#ifdef WIN32
    QString cmd("icacls.exe "") ;
    cmd += filePath;
    cmd += "" /grant Everyone:(F)";
    STARTUPINFOW si;
    PROCESS_INFORMATION pi;
    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);

    #ifndef _DEBUG 
        si.dwFlags = STARTF_USESHOWWINDOW;
        si.wShowWindow = SW_HIDE;
    #endif

    ZeroMemory(&pi, sizeof(pi));
    CreateProcessW (NULL,  　　　　　　// No module name (use command line). 
　　　　(wchar_t*)cmd.utf16(),        // Command line. 
　　　　NULL,                         // Process handle not inheritable. 
　　　　NULL,                         // Thread handle not inheritable. 
　　　　FALSE,                        // Set handle inheritance to FALSE. 
　　　　0,                            // No creation flags. 
　　　　NULL,                         // Use parent's environment block. 
　　　　NULL,                         // Use parent's starting directory. 
　　　　&si,                          // Pointer to STARTUPINFO structure.
　　　　&pi);                         // Pointer to PROCESS_INFORMATION structure. 


　　WaitForSingleObject(pi.hProcess, INFINITE);
　　CloseHandle(pi.hProcess);
　　CloseHandle(pi.hThread);
#endif
}

5.判断系统64位

static bool IsWin64 (void)
{
    SYSTEM_INFO si = {0};
    typedef void (WINAPI *LPFN_PGNSI)(LPSYSTEM_INFO);
    LPFN_PGNSI pGNSI = (LPFN_PGNSI)GetProcAddress(GetModuleHandleA(("kernel32.dll")),"GetNativeSystemInfo");

    if (pGNSI) pGNSI(&si);

    if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64)
    {
        return true;
    }
    return false;
}

6.文件生成md5值

static bool GetFileMd5Code(const QString strFilePath, QString &strMD5Code)
{
        bool bRet = false;
        strMD5Code = "";

        if (!QFile::exists(strFilePath))
        {
            qDebug() << strFilePath << " don't exist!";
            return bRet;
        }

        QFile file(strFilePath);
        if (file.open(QIODevice::ReadOnly))
        {
            QCryptographicHash cryptographicHash(QCryptographicHash::Md5);
            cryptographicHash.addData(&file);
            strMD5Code = QString::fromLatin1(cryptographicHash.result().toHex());
            file.close();
            bRet = true;
        }

        qDebug() << "md5:" << strMD5Code;
        return bRet;
    }

    qDebug() << "md5:" << strMD5Code;
    return bRet;
}

QByteArray块数据生成Md5

QByteArray GetByteArrayMd5(const QByteArray &byteArrayData)
{ 
    return QCryptographicHash::hash(byteArrayData, QCryptographicHash::Md5).toHex();
}

7.版本号比较(字符串比较)

int CompareVersion(QString strVer1, QString strVer2)
{
    if ( !strVer1.compare( strVer2 ) )
    {
        return 0;
    }

    QStringList list1 = strVer1.split( "." );
    QStringList list2 = strVer2.split( "." );

    int iTotal1 = list1.count();
    int iTotal2 = list2.count();

    int iTotal=iTotal1>iTotal2?iTotal2:iTotal1;

    int iValue1 = 0, iValue2 = 0;
    bool ibOK1 = false, ibOK2 = false;
    for ( int iNum = 0; iNum < iTotal; ++iNum )
    {
        iValue1 = list1[iNum].toInt( &ibOK1 );
        if (!ibOK1)
        {
            iValue1=0;
        }

        iValue2 = list2[iNum].toInt( &ibOK2 );
        if (!ibOK2)
        {
            iValue2=0;
        }

        if (iValue1==iValue2)
        {
            continue;
        }
        else if ( iValue1 < iValue2 )
        {
            return -1;
        }
        else
        {
            return 1;
        }
    }

    return iTotal1<iTotal2?-1:1;
}

测试：

CompareVersion("16.01.19", "16.01.19") //return 0;
CompareVersion("16.01.19", "16.01.18") //return 1;
CompareVersion("16.01.18", "16.01.19") //return -1;
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原文地址：https://www.cnblogs.com/sz-leez/p/6537004.html