Qt简易计算器代码

1、cwidget.cpp#include "cwidget.h"#define key_clr "clr"#define key_add "+"#define key_sub "-"#define key_mul "*"#define key_div "/"#define key_eq "="#define key_0 "0"#define key_1 "1"#define key_2 "2"#de

2、fine key_3 "3"#define key_4 "4"#define key_5 "5"#define key_6 "6"#define key_7 "7"#define key_8 "8"#define key_9 "9"#define buttonwidth 30 /定义按键的长度#define buttonheight 30 /定义按键的宽度static char *buttontext = /定义静态全局变量key_1,key_2,key_

3、3,key_4,key_5,key_6,key_7,key_8,key_9,key_add,key_sub,key_mul,key_div,key_eq,key_clr,key_0;cwidget:cwidget(qwidget *parent, char *name) /构造函数initialize();createform();cwidget:cwidget() /析构函数，销毁各个按键delete edit;delete *button;delete mainlayout;delete toplayout;delete bottomlayout;void cwidget:calculat

4、e() /响应按键“=”，调用计算功能switch(oper)case qt:key_plus: /加法firstnum += secondnum;break;case qt:key_minus: /减法firstnum -= secondnum;break;case qt:key_asterisk: /乘法firstnum *= secondnum;break;case qt:key_slash: /除法firstnum /= secondnum;break;default: firstnum = firstnum;edit->settext(qstring:number(firstn

5、um);void cwidget:setvalue()qstring tempstr;tempstr = edit->text(); /显示框中的数值赋给tempstrif(tempstr.length() < edit->maxlength() /小于显示框允许的最大位数tempstr += (qpushbutton *)sender()->text(); /将按键对应的数值添加tempstr elseqmessagebox:information( this, tr("calculator"),tr("too long!");

6、 /位数过多，报错if(-1=oper) /没有按加减乘除、等于、清空键 firstnum = tempstr.toint(); /把tempstr转换成整型数，赋给第一个计算数edit->settext(qstring:number(firstnum); /变成字符串之后，显示else /之前按过加减乘除、等于、清空键secondnum = tempstr.toint(); edit->settext(qstring:number(secondnum); void cwidget:setoper() /将按键转换成qt能识别的语言qstring str=(qpushbutton

7、*)sender()->text();if(str = "+")onclicked(qt:key_plus); / qt中使用的“+”键的名称else if(str = "-")onclicked(qt:key_minus); / qt中使用的“”键的名称。else if(str = "*")onclicked(qt:key_asterisk); / qt中使用的“*”键的名称。else if(str = "/")onclicked(qt:key_slash); / qt中使用的“/”键的名称。else if

8、(str = "=")onclicked(qt: key_equal); /点击等于号，调用计算函数void cwidget:clear()edit->clear(); /清空显示框，clear（）为内部函数edit->settext(tr("%1").arg(0); /这个函数可获取文本编辑框中光标的位置，并显示在状态栏中 / settext(tr(“%1行 %2列”).arg(rownum).arg(colnum);initialize(); /调用初始化函数void cwidget:initialize()firstnum = 0;se

9、condnum = 0;oper = -1;void cwidget:createform()setminimumsize(80,200); /最小窗口setmaximumsize(80,200); /最大窗口 mainlayout = new qvboxlayout(this,20); /整体布局，以当前窗口为基准，（垂直间隔）离边界20 toplayout = new qhboxlayout(mainlayout,30); /水平布局，包含在mainlayout里，水平间隔30edit = new qlineedit(this,"edit"); /edit->se

10、talignment(qt:alignright); /数值从右边开始出来edit->setmaxlength(9); /最多9位数edit->settext(tr("%1").arg(0); /光标位置edit->setreadonly(true); /设为只读模式 toplayout->addwidget(edit); /先布置显示框 bottomlayout = new qgridlayout(mainlayout,4,4,10); /布置在mainlayout里，4行、4列、间隔10 int n; for(int r=0; r<3; r

11、+) /19阵列 for(int c=0; c<3; c+) n = c+3*r; buttonn = new qpushbutton(buttontextn,this,buttontextn); /构造一个名称为n、父对象为parent并且文本为n的推动按钮 buttonn->setfixedsize(buttonwidth,buttonheight); /设置按键大小 bottomlayout->addwidget(buttonn,r,c); /从右上角为第1（r+1）行，第1（c+1）列 connect(buttonn,signal(clicked(),this,slo

12、t(setvalue(); button9 = new qpushbutton(buttontext9,this,buttontext9); / “ + ” button9->setfixedsize(buttonwidth,buttonheight); bottomlayout->addwidget(button9,0,3); / 第1行第4列 connect(button9,signal(clicked(),this,slot(setoper(); button10 = new qpushbutton(buttontext10,this,buttontext10); / “”

13、button10->setfixedsize(buttonwidth,buttonheight); bottomlayout->addwidget(button10,1,3); /第2行第4列 connect(button10,signal(clicked(),this,slot(setoper(); button11 = new qpushbutton(buttontext11,this,buttontext11); / “ * ” button11->setfixedsize(buttonwidth,buttonheight); bottomlayout->addw

14、idget(button11,2,3); /第3行第4列 connect(button11,signal(clicked(),this,slot(setoper(); button12 = new qpushbutton(buttontext12,this,buttontext12); / “ / ” button12->setfixedsize(buttonwidth,buttonheight); bottomlayout->addwidget(button12,3,3); /第4行第4列 connect(button12,signal(clicked(),this,slot(s

15、etoper(); button13 = new qpushbutton(buttontext13,this,buttontext13); / “ = ” button13->setfixedsize(buttonwidth,buttonheight); bottomlayout->addwidget(button13,3,2); /第4行第3列 connect(button13,signal(clicked(),this,slot(calculate(); /按下，调用calculate函数 button14 = new qpushbutton(buttontext14,this

16、,buttontext14); / 清空 button14->setfixedsize(buttonwidth,buttonheight); bottomlayout->addwidget(button14,3,1); /第4行第2列 connect(button14,signal(clicked(),this,slot(clear(); button15 = new qpushbutton(buttontext15,this,buttontext14); / “ 0 ” button15->setfixedsize(buttonwidth,buttonheight); bo

17、ttomlayout->addwidget(button15,3,0); /第4行第1列 connect(button15,signal(clicked(),this,slot(setvalue();bool cwidget:event(qevent *e)if(e->type() = qevent:keypress) /按钮按下事件qkeyevent *keyevent = static_cast<qkeyevent*>(e);switch(keyevent->key()case qt:key_plus:onclicked(qt:key_plus);break;

18、case qt:key_minus:onclicked(qt:key_minus);break;case qt:key_asterisk:onclicked(qt:key_asterisk);break;case qt:key_slash:onclicked(qt:key_slash);break;case qt:key_equal:calculate();break;return qwidget:event(e);void cwidget:onclicked(int key) /响应按键事件edit->clear(); /按下功能按键，清空显示框edit->settext(tr(

19、"%1").arg(0); /设置光标位置oper = key; /oper重新赋值cwidget.h#include <qstring.h>#include <qevent.h>#include <qmessagebox.h>class cwidget : public qwidget /qwidget类是所有用户界面对象的基类q_object /qobject用于无缝对象通讯的被叫做信号和槽的非常强大的机制。public:cwidget(qwidget *parent=0, char *name=0); /如果parent为0，新的窗口部件变为顶级窗口cwidget();private: /定义的成员只能在该类及其子类中访问qlineedit *edit; / 显示框qpushbutton *button16; / 定义16个按键qvboxlayout *mainlayout; / 垂直布局qhboxlayout *toplayout;