QT，计算器实现（四则运算，括号，小数，负数） |
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QT，计算器实现（四则运算，括号，小数，负数）
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初学Qt，制作一个简单计算器。 先上效果图： （2）—->input + old_put = “1+”;//显示到上框 new_put = “0”;//初始化 （3）—->input 2 old_put = “1+”;//显示到上框 new_put = “2”; （4）—->input = old_put = “1+2”;//不显示，计算结果显示到下框，上框清空 new_put = “0”; old_put = “0”;//初始化 3，计算器按键输入信号绑定connect。 /*所有按键，信号连接*/ connect(ui>button_0,SIGNAL(clicked()),this,SLOT(push_button_0())); connect(ui->button_1,SIGNAL(clicked()),this,SLOT(push_button_1())); connect(ui->button_2,SIGNAL(clicked()),this,SLOT(push_button_2())); connect(ui->button_3,SIGNAL(clicked()),this,SLOT(push_button_3())); connect(ui->button_4,SIGNAL(clicked()),this,SLOT(push_button_4())); connect(ui->button_5,SIGNAL(clicked()),this,SLOT(push_button_5())); connect(ui->button_6,SIGNAL(clicked()),this,SLOT(push_button_6())); connect(ui->button_7,SIGNAL(clicked()),this,SLOT(push_button_7())); connect(ui->button_8,SIGNAL(clicked()),this,SLOT(push_button_8())); connect(ui->button_9,SIGNAL(clicked()),this,SLOT(push_button_9())); connect(ui->button_point,SIGNAL(clicked()),this,SLOT(push_button_point())); connect(ui->button_left,SIGNAL(clicked()),this,SLOT(push_button_left())); connect(ui->button_right,SIGNAL(clicked()),this,SLOT(push_button_right())); connect(ui->button_add,SIGNAL(clicked()),this,SLOT(push_button_add())); connect(ui->button_minus,SIGNAL(clicked()),this,SLOT(push_button_minus())); connect(ui->button_ride,SIGNAL(clicked()),this,SLOT(push_button_ride())); connect(ui->button_divide,SIGNAL(clicked()),this,SLOT(push_button_divide())); connect(ui->button_equal,SIGNAL(clicked()),this,SLOT(push_button_equal())); connect(ui->button_AC,SIGNAL(clicked()),this,SLOT(push_button_AC())); connect(ui>button_CE,SIGNAL(clicked()),this,SLOT(push_button_CE()));4，按键输入处理函数。主要注意的就是（），+,-,*,/,小数点的输入，数字输入主要注意0的输入即可，下方是详细代码。仔细看一下应该就可以懂得，没有很多复杂的操作，都是字符串和逻辑的操作。 /*数据按键输入*/ void Calculator::push_button_0() { if(put_ctrl.new_put == "0"){ put_ctrl.new_put = "0"; put_ctrl.update_flag = 1; } else put_ctrl.new_put += "0"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_1() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "1"; else put_ctrl.new_put += "1"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_2() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "2"; else put_ctrl.new_put += "2"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_3() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "3"; else put_ctrl.new_put += "3"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_4() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "4"; else put_ctrl.new_put += "4"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_5() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "5"; else put_ctrl.new_put += "5"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_6() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "6"; else put_ctrl.new_put += "6"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_7() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "7"; else put_ctrl.new_put += "7"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_8() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "8"; else put_ctrl.new_put += "8"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_9() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "9"; else put_ctrl.new_put += "9"; ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_point() { if(put_ctrl.new_put == "0") put_ctrl.new_put = "0."; else{ if(-1 == put_ctrl.new_put.indexOf(".")) put_ctrl.new_put += "."; } ui->put_data->setText(put_ctrl.new_put); } void Calculator::push_button_left() { if(put_ctrl.old_put == "0"){ put_ctrl.old_put = "("; put_ctrl.brackets_cnt ++; } else{ put_ctrl.old_put += "("; put_ctrl.brackets_cnt ++; } ui->display->setText(put_ctrl.old_put); } void Calculator::push_button_right() { if(put_ctrl.brackets_cnt > 0){ QString::iterator p = put_ctrl.old_put.end()-1; if(*p != ')') put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += ")"; put_ctrl.brackets_cnt --; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; ui->display->setText(put_ctrl.old_put); } } /*+ - * / = 按键输入*/ void Calculator::push_button_add() { if(put_ctrl.old_put == "0"){ put_ctrl.old_put = put_ctrl.new_put; put_ctrl.old_put += "+"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } else{ QString::iterator p = put_ctrl.old_put.end()-1; if(*p == '+' || *p == '-' || *p == '*' || *p == '/' || *p == '(' ){ if(put_ctrl.new_put == "0"){ if(put_ctrl.update_flag){ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "+"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else{ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "+"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else if(*p == ')') { put_ctrl.old_put += "+"; } } ui->display->setText(put_ctrl.old_put); } void Calculator::push_button_minus() { if(put_ctrl.old_put == "0"){ put_ctrl.old_put = put_ctrl.new_put; put_ctrl.old_put += "-"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } else{ QString::iterator p = put_ctrl.old_put.end()-1; if(*p == '+' || *p == '-' || *p == '*' || *p == '/' || *p == '(' ){ if(put_ctrl.new_put == "0"){ if(put_ctrl.update_flag || *p == '('){ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "-"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else{ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "-"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else if(*p == ')') { put_ctrl.old_put += "-"; } } ui->display->setText(put_ctrl.old_put); } void Calculator::push_button_ride() { if(put_ctrl.old_put == "0"){ put_ctrl.old_put = put_ctrl.new_put; put_ctrl.old_put += "*"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } else{ QString::iterator p = put_ctrl.old_put.end()-1; if(*p == '+' || *p == '-' || *p == '*' || *p == '/' || *p == '(' ){ if(put_ctrl.new_put == "0"){ if(put_ctrl.update_flag){ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "*"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else{ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "*"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else if(*p == ')') { put_ctrl.old_put += "*"; } } ui->display->setText(put_ctrl.old_put); } void Calculator::push_button_divide() { if(put_ctrl.old_put == "0"){ put_ctrl.old_put = put_ctrl.new_put; put_ctrl.old_put += "/"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } else{ QString::iterator p = put_ctrl.old_put.end()-1; if(*p == '+' || *p == '-' || *p == '*' || *p == '/' || *p == '(' ){ if(put_ctrl.new_put == "0"){ if(put_ctrl.update_flag){ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "/"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else{ put_ctrl.old_put += put_ctrl.new_put; put_ctrl.old_put += "/"; put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } }else if(*p == ')') { put_ctrl.old_put += "/"; } } ui->display->setText(put_ctrl.old_put); } void Calculator::push_button_equal() { if(put_ctrl.old_put == "0"){ push_button_AC(); return; } else{ QString::iterator p = put_ctrl.old_put.end()-1; if(*p == '+' || *p == '-' || *p == '*' || *p == '/' || *p == '(' ){ put_ctrl.old_put += put_ctrl.new_put; if(put_ctrl.brackets_cnt > 0){ for(int i = 0 ; i < put_ctrl.brackets_cnt ; i++) put_ctrl.old_put += ")"; } put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; }else if(*p == ')') { if(put_ctrl.brackets_cnt > 0){ for(int i = 0 ; i < put_ctrl.brackets_cnt ; i++) put_ctrl.old_put += ")"; } put_ctrl.new_put = "0"; put_ctrl.update_flag = 0; } } calculate_result(put_ctrl.old_put); put_ctrl.old_put = "0"; put_ctrl.brackets_cnt = 0; put_ctrl.update_flag = 0; put_ctrl.new_put = "0"; } void Calculator::push_button_CE() { put_ctrl.old_put = "0"; ui->display->clear(); } void Calculator::push_button_AC() { put_ctrl.old_put = "0"; put_ctrl.new_put = "0"; put_ctrl.brackets_cnt = 0; put_ctrl.update_flag = 0; ui->display->clear(); ui->put_data->setText(put_ctrl.new_put); }5，获得的表达式如何计算。这里贴下计算的源码，详细的下篇博客分析一下。 /*获取操作符优先级*/ int Calculator::Priority(QString data) { int priority; if(data == "(") priority = 1; else if(data == "+" || data == "-") priority = 2; else if(data == "*" || data == "/") priority = 3; else if (data == ")") priority = 4; else priority = -1; return priority; } /*将表达式的数据，操作符分割，依次存入mask_buffer数组中*/ int Calculator::mask_data(QString expression, QString *mask_buffer) { int i,k = 0,cnt = 0; QString::iterator p = expression.begin(); int length = expression.length(); for(i = 0 ; i < length ; i += cnt,k++) { cnt = 0; if(*p >= '0' && *p = '0' && *p Priority(st2.top())) st2.push(mask_buffer[j]); else{ while(Priority(mask_buffer[j]) display->clear(); ui->put_data->setText("0 不能做除数"); return -1; } } } } QString res = QString::number(st.top(),'g',10); ui->display->clear(); ui->put_data->setText(res); return st.top(); } /*表达式计算整合*/ void Calculator::calculate_result(QString expression) { QString mask_buffer[100]={"0"},repolish[100]={"0"}; int length = mask_data(expression,mask_buffer); length = re_polish(mask_buffer,repolish,length); double result = repolish_calculat(repolish,length); }6，源码包。 为了方便，我这里将整个工程打包，大家如果需要的话可以下载。还有很多不足之处，希望一起交流，进步。 链接：http://pan.baidu.com/s/1i5R67zv 密码：dd9s |
上面显示框，用于显示输入： 如：1*2-（3-8）+2*6 
按下等于键，下面显示框显示输出结果： 
1，计算器界面设计 因为本人初学，就直接在ui界面画出所需界面了，如下： 
在界面画好之后，记得要布局，让其界面一直处于居中状态，另外可以右键，选择修改每个控件名字，便于对各个控件编程。 2，总体设计思路。 由界面设计。我们可以看出，有两个显示框，当我们输入表达式时，要实时显示到界面上，那我们可以将上面的框用于显示输入表达式，下面的框用于显示输入的数据及最后的运算结果。 我们定义一个结构体： struct put_ctrl_t{ QString old_put; //用于表达式的存储 QString new_put; //用于输入的数据存储 int brackets_cnt; //左括号输入个数 int update_flag; //当new_put为“0”时，重新输入0表示更新置1 }; 计算器是模仿win10的自带的标准计算器，显示方式和其相似。 当我们输入1+2=时， （1）—>input 1 old_put = “0”;//初始值 new_put = “1”;【本文地址】