错误:cannot convert 'QString' to 'const char*' for argument '1' to 'int system(const char*)'

   若：    QString  str1 = "date -s 04/30/2012";

             system(str1);//

则：/home/qust/qt/time-build-desktop-Desktop_Qt_4_8_0_for_GCC__Qt_SDK____/../time/mainwindow.cpp:31: 错误:cannot convert 'QString' to 'const char*' for argument '1' to 'int system(const char*)'

修改：

QString  str1 = "date -s 04/30/2012";

             system(str1.toLatin1().data());//

QByteArray QString::toLatin1 () const

Returns a Latin-1 representation of the string as a QByteArray.

The returned byte array is undefined if the string contains non-Latin1 characters. Those characters may be suppressed or replaced with a question mark.

char * QByteArray::data ()

Returns a pointer to the data stored in the byte array. The pointer can be used to access and modify the bytes that compose the array. The data is '\0'-terminated, i.e. the number of bytes in the returned character string is size() + 1 for the '\0' terminator.

Example:

 QByteArray ba("Hello world"); char *data = ba.data(); while (*data) {     cout << "[" << *data << "]" << endl;     ++data; }