Qt中各种数据类型之间的相互转换

QString str = "12";  
bool ok;  
int hex = str.toInt(&ok, 16);       // 以16进制的形式转换 hex = 18  
int dec = str.toInt(&ok, 10);       // 以10进制的形式转换 dec = 12  

QString str = "1234.56";  
double val = str.toDouble();   // val == 1234.56 

QString str1 = "1234.56";  
str1.toFloat();             // returns 1234.56  

long a = 63;  
QString s = QString::number(a, 16);               // s == "3f"  
QString t = QString::number(a, 16).toUpper();     // t == "3F"  

QString mon = QString("%1").arg(temp); //将temp转化字符串

QString x = "Nine pineapples";  
QString y = x.mid(5, 4);            // y == "pine"  
QString z = x.mid(5);               // z == "pineapples"  

QString i;           // current file's number  
QString total;       // number of files to process  
QString fileName;    // current file's name  
  
QString status = QString("Processing file %1 of %2: %3").arg(i).arg(total).arg(fileName);  
//First, arg(i) replaces %1. Then arg(total) replaces %2. Finally, arg(fileName) replaces %3.  

QString str = "cxd";  
int i = str.legth(); // i =3 

str.clear(); 

QString x = "free";  
QString y = "dom";  
x.append(y);   //x == "freedom"  

QString str = "colour behaviour flavour neighbour";  
str.replace(QString("ou"), QString("o"));  
// str == "color behavior flavor neighbor" 

QByteArray Data;
QString S = QString::fromAscii(Data.data());

QByteArray Data;                       //Data = ONP00001
QString Qnum = QString(Data.mid(5,3)); //Qnum = "001"
int Inum = Qnum.toInt();               //Inum = 1