Qt 常用数据类型转换

QByteArray转QString

QByteArray byte;
QString str;
byte = str.toLatin1();

QString转QByteArray

QByteArray byte;
QString str;
str = QString(byte);

QString转String

QString str;
std::string st;
st = str.toStdString();*

String转QString

QString str;
std::string st;
str = QString::fromStdString(st);

QByteArray转char*

char *ch;//不能定义成ch[n],数组和指针不一样
QByteArray byte;
ch = byte.data();

char*转QByteArray

char *ch;//不能定义成ch[n],数组和指针不一样
QByteArray byte;
byte = QByteArray(ch);

QString转char*

QString str;
char *ch;
ch = str.toLatin1().data();

char*转QString

char *ch;
QString str = QString(QLatin1String(ch));

QString转char

char ch[50];
QString ss;
ch = ss.toLocal8Bit().data();

QHostAddress转QString

QHostAddress host;
QString str = host.toString();

QString转QHostAddress

QString str;
QHostAddress host(ss);

int转QString

int n;
QString str = QString::number(n);

QString转int

QString str;
int n = str.toInt();

CString转QString

CString str;
std::wstring wstr = (LPCTSTR)str;
QString qstr = QString::fromStdWString(wstr);

数据操作

c = qAbs(a); //返回a的绝对值
max = qMax(a,b);//返回a与b中的最大值
int nRound = qRound(a);//四舍五入
qSwap(a,b);//交换两数的值*