C++各种类型的char*、QString、string、wstring、BSTR格式相互转化

(1)char*转QString
char* pages;
QString inputpage = QString(QLatin1String(pages));
 
(2)QString转char*
QString str; 
char* ch; 
QByteArray ba = str. toLocal8Bit(); // must 
ch=ba.data();
 
(3)QString转换string
string dome1；  
QString dome2；  
dome1 = dome2.toStdstring();  
(4)string转化为QString
string dome1;  
QString dome2;  
dome2 = QString::fromestdstring(dome1);  
 
(5)string转化char*
string dome1;  
char dome2[20];  
dome = dome1.c_str();  
(6)char*转化为string
char dome1[20] = "hello world!";  
string dome2(dome1); 
 
(7)int/float/double转QString
long a = 63;  
QString s = QString::number(a, 10);             // s == "63"  
QString t = QString::number(a, 16).toUpper();     // t == "3F"  
 
(8)QString转int/float/double
QString str="123.45";  
double val=str.toDouble(); 
float val=str.toFloat();   
int val=str1.toInt();   
 
(9)QString转wstring（QString 转 BSTR）
QString qstr; 
BSTR bstr = SysAllocStringLen((OLECHAR*)qstr.unicode(), qstr.length()); 
BSTR bstr = SysAllocString((OLECHAR*)qstr.unicode());