字符串转换

// 将 char* 转换为 string
const char* c_str = “Hello, world!”;
std::string str = c_str;

// 将 string 转换为 char*
std::string str = “Hello, world!”;
const char* c_str = str.c_str();

// 将 string 转换为 QString
std::string str = “Hello, world!”;
QString qstr = QString::fromStdString(str);

// 将 QString 转换为 string
QString qstr = “Hello, world!”;
std::string str = qstr.toStdString();

// 将 char* 转换为 QString
const char* c_str = “Hello, world!”;
QString qstr = QString::fromUtf8(c_str);

// 将 QString 转换为 char*
1）QString qstr = “Hello, world!”;
const char* c_str = qstr.toStdString().c_str();

2）QString qstr = “Hello, world!”;
QByteArray bytes = qstr.toUtf8();
const char* c_str = bytes.constData();