QT各种数据格式转换

QT有多种数据类型，掌握各种数据类型的转换至关重要。

整型     qint32

字符串 QString

字符型 char，const char

数组     QByteArray

int to str

QString str;
qint32  i = 1;
str =  tr("%1").arg(i);  //参数转换
str = "/root/Documents/"+ i +".bmp"; //自动转换

char to int

char a;
qint32 b = (qint32)a;

char to string

char a = 'b';

QString str = QString(a);

char* to const char*

char *ch1="hello11";
const char *ch2="hello22";
ch2 = ch1;//不报错，但有警告
ch1 = (char *)ch2;

string to char*

QString str = "abc";

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

QByteArray to char *

QByteArray byte;
char *ch = byte.data();  //don't use ch[];

char *   to   QByteArray

char *ch;
QByteArray byte = QByteArray(ch);

QString to QByteArray

QString string;
QByteArray byte = string.toAscii();//you can use the .toutf8();

QByteArray to  QString

QByteArray byte;
QString string = QString(byte);

int to QString

int a=10;
QString b=QString::number(a)

QString to int

QString a="120"
int b=a.toInt();