[C++知识库]QT 字符串转换

#include "Windows.h"
char* UnicodeToAnsi(const wchar_t* szStr)
{
?? ?int nLen = WideCharToMultiByte(CP_ACP, 0, szStr, -1, NULL, 0, NULL, NULL);
?? ?if (nLen == 0)
?? ?{
?? ? ? ?return NULL;
?? ?}
?? ?char* pResult = new char[nLen];
?? ?WideCharToMultiByte(CP_ACP, 0, szStr, -1, pResult, nLen, NULL, NULL);
?? ?return pResult;
}
wchar_t* AnsiToUnicode(const char* szStr)
{
?? ?int nLen = MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, szStr, -1, NULL, 0);
?? ?if (nLen == 0)
?? ?{
?? ? ? ?return NULL;
?? ?}
?? ?wchar_t* pResult = new wchar_t[nLen];
?? ?MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, szStr, -1, pResult, nLen);
?? ?return pResult;
}
qDebug() << "====================================";
//QString转string
QString qstr1 = "demo";
std::string str1 = qstr1.toStdString();
qDebug() << QString::fromStdString(str1);
//QString转wstring
std::wstring wstr1 = qstr1.toStdWString();
qDebug() << QString::fromStdWString(wstr1);
//QString转const char*
std::string str2 = qstr1.toStdString();
const char* cstr1 = str2.c_str();
qDebug() << QString::fromStdString(cstr1);
//QString转char*
QByteArray bytearray1 = qstr1.toLocal8Bit();
char* cstr2 = bytearray1.data();
qDebug() << QString::fromLocal8Bit(cstr2);
//QString转char[]
char cstr3[128];
std::strcpy(cstr3, qstr1.toStdString().data());
qDebug() << QString::fromStdString(cstr3);
//QString转uchar*
QByteArray bytearray2 = qstr1.toLocal8Bit();
unsigned char* ustr1 = (unsigned char *)bytearray2.data();
qDebug() << QString::fromLocal8Bit((char*)ustr1);
//QString转QByteArray
QByteArray bytearray3 = qstr1.toLocal8Bit();
qDebug() << QString::fromLocal8Bit(bytearray3);


qDebug() << "====================================";
//string转QString
std::string str3 = "demo";
QString qstr2 = QString::fromStdString(str3);
qDebug() << qstr2;
//string转const char*
const char* cstr4 = str3.data();
qDebug() << QString::fromStdString(cstr4);
//string转char*
char cstr5[128];
strcpy(cstr5, str3.c_str());
qDebug() << QString::fromStdString(cstr5);
//string转char*
char* cstr6 = const_cast<char*>(str3.data());
qDebug() << QString::fromStdString(cstr6);


qDebug() << "====================================";
//const char*转QString
const char* cstr7 = "demo";
QString qstr3 = QString(cstr7);
qDebug() << qstr3;
//char*转QString
char* cstr8 = (char*)"demo";
QString qstr5 = QString(cstr8);
qDebug() << qstr5;
//char[]转QString
char cstr9[128] = "demo";
QString qstr4 = QString(cstr9);
qDebug() << qstr4;


qDebug() << "====================================";
//const char*转string
const char* cstr10 = "demo";
std::string str4(cstr10);
qDebug() << QString::fromStdString(str4);
//char*转string
char* cstr11 = (char*)"demo";
std::string str5(cstr11);
qDebug() << QString::fromStdString(str5);
//char[]转string
char cstr12[128] = "demo";
std::string str6(cstr12);
qDebug() << QString::fromStdString(str6);


qDebug() << "====================================";
//const char*转char*
const char* cstr13 = "demo";
char* cstr14 = const_cast<char*>(cstr13);
qDebug() << QString::fromStdString(cstr14);
//char*转const char*
char* cstr15 = (char*)"demo";
const char* cstr16 = cstr15;
qDebug() << QString::fromStdString(cstr16);
//char*转char[]
char cstr17[128];
char* cstr18 = (char*)"demo";
strcpy(cstr17, cstr18);
qDebug() << QString::fromStdString(cstr17);
//char[]转char*
char cstr19[128] = "demo";
char* cstr20 = cstr19;
qDebug() << QString::fromStdString(cstr20);


qDebug() << "====================================";
//QByteArray转QString
QByteArray bytearray4 = "demo";
QString qstr6 = QString(bytearray4);
qDebug() << qstr6;
//QByteArray转char*
char* str21 = bytearray4.data();
qDebug() << QString::fromStdString(str21);
//char*转QByteArray
char* str22 = (char*)"demo";
QByteArray bytearray5;
bytearray5 = QByteArray(str22);
qDebug() << QString(bytearray5);


qDebug() << "====================================";
//QString转unsigned char
QString qstr7 = "129";
bool ok1;
unsigned char uchar1 = (unsigned char)qstr7.toUShort(&ok1, 16);
qDebug() << uchar1;
//十六进制转十进制
bool ok2;
QString hexstr1 = "129";
int dec1 = hexstr1.toInt(&ok2, 16);
qDebug() << QString::number(dec1);
//十进制转十六进制
int dec2 = 297;
QString hexstr2 = QString("%1").arg(dec2, 4, 16, QLatin1Char('0'));
qDebug() << hexstr2;


qDebug() << "====================================";
//short int float double long转QString
short test1 = 2;
int test2 = 3;
float test3 = 4.6;
double test4 = 8.7;
long test5 = 29999;
qDebug() << QString::number(test1, 10) << QString::number(test2, 10) << QString::number(test3, 'f', 2) << QString::number(test4, 'f', 2) << QString::number(test5);
//QString转short int float double long
QString qstr8 = "22";
qDebug() << qstr8.toShort() << qstr8.toInt() << qstr8.toFloat() << qstr8.toDouble() << qstr8.toLong();