QMargins Class
#include<QMargins>
介绍
QMargins定义了矩形的四个外边距量，left,top,right和bottom，描述围绕矩形的边框宽度。
公用函数
QMargins()
QMargins(int left,int top, int right, int bottom) 构造函数
bool isNull() const 如果四个值都为0返回true
int bottom() const
int left() const
int right() const
int top() const
void setBottom(int bottom)
void setLeft(int left)
void setRight(int right)
void setTop(int Top)
相关运算符的重载
数量繁杂而且不好记忆，作为手册来检索就可以了
QMargins & operator*=(int)
QMargins & operator*=(qreal)
QMargins &operator+=(const QMargins & margins)
QMargins & operator+=(int)
QMargins &operator-=(const QMargins & margins)
QMargins & operator-=(int)
QMargins & operator/=(int)
QMargins &operator/=(qreal)
bool operator!=(const QMargins& m1, const QMargins & m2)
QMargins operator*(constQMargins & margins, int factor)
QMargins operator*(int factor,const QMargins & margins)
QMargins operator*(constQMargins & margins, qreal factor)
QMarginsoperator*(qreal factor, const QMargins & margins)
QMargins operator+(constQMargins & m1, const QMargins & m2)
QMargins operator-(constQMargins & m1, const QMargins & m2)
QMargins operator-(constQMargins & margins)
QMargins operator/(constQMargins & margins, int divisor)
QMargins operator/(constQMargins & margins, qreal divisor)
QDataStream &operator<<(QDataStream & stream, const QMargins & m)
bool operator==(const QMargins& m1, const QMargins & m2)
QDataStream &operator>>(QDataStream & stream, QMargins & m)
