嵌入式QT图形界面设计考试题

1、真诚为您提供优质参考资料，若有不当之处，请指正。11级3G嵌入式班：吕中旭 嵌入式QT图形界面设计考试题1、 设计一个类似于QQ登陆界面的程序，要求1） 有用户名输入框、密码输入框2） 有确认按钮、退出按钮3） 当点击确认按钮时，检查密码和用户名是否匹配默认密码和用户名（默认Passwd:123456,UserName:ct）,如果匹配登陆界面退出，否则弹出警告框。4） 当点击退出按钮时，退出登陆界面。程序代码：“CSS2.cpp”#ifndef CSS2_H#define CSS2_H#include#include#include#include#include#include#inclu

2、de#include class LOGIN:public QDialog /定义一个LOGIN（登录）的类 Q_OBJECTpublic: LOGIN(QWidget *parent =0); /公共成员 QWidget指针parent默认值为0private: /私有成员 QLabel * userlabel; /用户名标签 QLabel *passwordlabel; /用户密码标签 QLineEdit * userlineedit; /用户名文本输入框 QLineEdit * passwordlineedit; /用户密码文本输入框 QPushButton * loginbutton;

3、 /定义登录按钮 QPushButton * quitbutton; /定义退出按钮 QVBoxLayout * VLlayout; /定义垂直布局管理器 QGridLayout * GLlayout; /定义网状布局管理器 QHBoxLayout * HLlayout; /定义水平布局管理器private slots: /定义私有槽 void login(); /引用用户登陆函数 void quit(); /引用用户退出函数;#endif / CSS2_H /用户登录函数css2.cpp#include css2.h LOGIN:LOGIN(QWidget *parent):QDialog(

4、parent)/将parent的参数传递过去 userlabel = new QLabel(username:); passwordlabel = new QLabel(passwd:); userlineedit = new QLineEdit; passwordlineedit = new QLineEdit; loginbutton = new QPushButton(login); quitbutton = new QPushButton(quit); VLlayout = new QVBoxLayout(this); GLlayout = new QGridLayout; HLlay

5、out = new QHBoxLayout; GLlayout-addWidget(userlabel,0,0); GLlayout-addWidget(userlineedit,0,1); GLlayout-addWidget(passwordlabel,1,0); GLlayout-addWidget(passwordlineedit,1,1); HLlayout -addWidget(loginbutton); HLlayout -addWidget(quitbutton); VLlayout -addLayout(GLlayout); VLlayout -addLayout(HLlay

6、out); setLayout(VLlayout); connect(loginbutton,SIGNAL(clicked(),this,SLOT(login(); connect(quitbutton,SIGNAL(clicked(),this,SLOT(quit();void LOGIN:login()/用户登录 if(userlineedit-text()!=ct)|(passwordlineedit-text()!=123456) QMessageBox:warning(this,warning, username or passwd is wrong!); else this-clo

7、se();void LOGIN:quit()/用户退出 QMessageBox:StandardButton mybutton; mybutton =QMessageBox:warning(this,warning,are you sure to quit the login?,QMessageBox:Yes|QMessageBox:No); if(mybutton=QMessageBox:Yes) this-close(); /主函数main.cpp#include#includecss2.hint main(int argc,char *argv) QApplication app(arg

8、c,argv); LOGIN logining; logining.show(); /显示登陆界面 return app.exec();效果截图：登陆界面： 用户名正确，密码不正确： 警告错误： 密码和用户都正确： 2、 设计实现一个简单的计算器程序，要求1） 能进行简单的+、-、*、/、1/x、sqart(开方)按键计算。2） 能进行退格、清零按键操作3） 能正确的显示结果，精度为0.01程序代码：BUTTON.cpp#ifndef BUTTON_H#define BUTTON_H#include class Button:public QToolButton /定义工具按钮类 Q_OBJE

9、CT public: Button(const QString &text,QWidget * parent=0); QSize sizeHint() const; ;#endif / BUTTON_H#ifndef CALCULATOR_H /定义计算器#define CALCULATOR_H#include#include /QT_BEGIN_HEADERclass QLineEdit;QT_END_NAMESPACEclass Button;class Calculaor:public QDialog Q_OBJECT public: Calculaor(QWidget * parent

10、=0); private slots: void digitClicked();/数字按键0-9 void unaryOperatorClicked();/平方，求根号，倒数 void additiveOperatorClicked();/“+”，“-” void multiplicativeOperatorClicked()；/“*”，“/” void equalClicked();/“=” void pointClicked();/“” void changeSignClicked();/“+ / ” void backspaceClicked();/“Backpase” void cle

11、ar();/“Clear” void clearAll();/“Clear All” void clearMemory();/“MC” void readMemory();/“MR” void setMemory();/“MS” void addToMemory();/“M +” private: Button * createButton(const QString &text,const char * membur); /生成按键函数 void abortOperation();/运算错误 bool calculate(double rightOperate,const QString &

12、pendingOperator); /运算函数（加减乘除） double sumInMemory; /MC,MR,MS,M+ 值保存 double sumSoFar; /加法和减法运算值保存 double factorSoFar; /乘法和除法运算值保存 QString pendingAdditiveOpertaor; /加法和减法运算值号保存QString pendingMultiplicativeOperator; /乘法和除法运算值号保存 bool waitingForOperand; /表示状态 QLineEdit * display;/数字框显示 enumNumDigitButton

13、s=10; Button *digitButtonsNumDigitButtons;/数字按键0-9;#endif / CALCULATOR_H/定义按钮函数#include#includebutton.hButton:Button(const QString &text,QWidget*parent):QToolButton(parent) setSizePolicy(QSizePolicy:Expanding,QSizePolicy:Preferred); setText(text);QSize Button:sizeHint()const QSize size=QToolButton:s

14、izeHint(); size.rheight()+=20; size.rwidth()=qMax(size.width(),size.height(); return size;#include #include #include button.h#include calculator.hCalculaor:Calculaor(QWidget *parent):QDialog(parent) sumInMemory=0.0; sumSoFar=0.0; factorSoFar=0.0; waitingForOperand=true; display=new QLineEdit(0); dis

15、play-setReadOnly(true); display-setAlignment(Qt:AlignRight); display-setMaxLength(15); QFont font=display-font(); font.setPointSize(font.pointSize()+8); display-setFont(font); for(int i=0;isetSizeConstraint(QLayout:SetFixedSize); mainLayout-addWidget(display,0,0,1,6); mainLayout-addWidget(backspaceB

16、utton,1,0,1,2); mainLayout-addWidget(clearButton,1,2,1,2); mainLayout-addWidget(clearAllButton,1,4,1,2); mainLayout-addWidget(clearMemoryButton,2,0); mainLayout-addWidget(readMemoryButton,3,0); mainLayout-addWidget(setMemoryButton,4,0); mainLayout-addWidget(addToMemoryButton,5,0); for(int i=1;iaddWi

17、dget(digitButtonsi,row,column); mainLayout-addWidget(digitButtons0,5,1); mainLayout-addWidget(pointButton,5,2); mainLayout-addWidget(changeSignButton,5,3); mainLayout-addWidget(divisionButton,2,4); mainLayout-addWidget(timesButton,3,4); mainLayout-addWidget(minusButton,4,4); mainLayout-addWidget(plu

18、sButton,5,4); mainLayout-addWidget(squareRootButton,2,5); mainLayout-addWidget(powerButton,3,5); mainLayout-addWidget(reciprocalButton,4,5); mainLayout-addWidget(equalButton,5,5); setLayout(mainLayout); setWindowTitle(tr(Calculator);Button *Calculaor:createButton(const QString &text,const char * mem

19、ber) Button *button=new Button(text); connect(button,SIGNAL(clicked(),this,member); return button;void Calculaor:digitClicked() /数字按键函数 Button *clickedButton = qobject_cast(sender(); int digitValue=clickedButton-text().toInt(); if(display-text()=0&digitValue=0.0)/清零 return; if(waitingForOperand) dis

20、play-clear(); waitingForOperand=false; display-setText(display-text()+QString:number(digitValue);void Calculaor:unaryOperatorClicked() /求平方，求根号，倒数的函数 Button *clickedButton = qobject_cast(sender(); QString clickedOperator = clickedButton - text(); double operand =display -text().toDouble(); double re

21、sult = 0.0; if(clickedOperator=Sqrt) if(operandsetText(QString:number(result); waitingForOperand=true;void Calculaor:additiveOperatorClicked() /加“+”减“-”操作函数 Button *clickedButton = qobject_cast(sender(); QString clickedOperator = clickedButton - text(); double operand =display -text().toDouble(); if

22、(!pendingMultiplicativeOperator.isEmpty() if(!calculate(operand,pendingMultiplicativeOperator) abortOperation(); return; display -setText(QString:number(factorSoFar); operand=factorSoFar; factorSoFar=0.0; pendingMultiplicativeOperator.clear(); if(!pendingMultiplicativeOperator.isEmpty() if(!calculat

23、e(operand,pendingMultiplicativeOperator) abortOperation(); return; display -setText(QString:number(sumSoFar); else sumSoFar=operand; pendingAdditiveOpertaor=clickedOperator; waitingForOperand=true; qDebug() look;void Calculaor:multiplicativeOperatorClicked()/乘“*”除“/”函数 Button *clickedButton = qobjec

24、t_cast(sender(); QString clickedOperator = clickedButton - text(); double operand =display -text().toDouble(); if(!pendingMultiplicativeOperator.isEmpty() if(!calculate(operand,pendingMultiplicativeOperator) abortOperation(); return; display -setText(QString:number(factorSoFar); else factorSoFar=ope

25、rand; pendingMultiplicativeOperator=clickedOperator; waitingForOperand=true;void Calculaor:equalClicked() /等于“=” 操作函数 double operand=display-text().toDouble(); if(!pendingMultiplicativeOperator.isEmpty() qDebug() *; if(!calculate(operand,pendingMultiplicativeOperator) abortOperation(); return; opera

26、nd=factorSoFar; factorSoFar=0.0; pendingMultiplicativeOperator.clear(); if(!pendingAdditiveOpertaor.isEmpty() qDebug() setText(QString:number(sumSoFar); sumSoFar=0.0; waitingForOperand=true;void Calculaor:pointClicked() /点“.” 操作函数 if(waitingForOperand) display-setText(0); if(! display-text().contain

27、s(.) display-setText(display-text()+tr(.); waitingForOperand=false;void Calculaor:changeSignClicked()/“加”“减”变换 操作函数 QString text=display-text(); double value=text.toDouble(); if(value0.0) text.prepend(tr(-); else if(valuesetText(text);void Calculaor:backspaceClicked()/退格函数 if(waitingForOperand) retu

28、rn; QString text =display-text(); text.chop(1); if(text.isEmpty() text=0; waitingForOperand=true; display-setText(text);void Calculaor:abortOperation()/终止操作函数 clearAll(); display-setText(tr(#);bool Calculaor:calculate(double rightOperand,const QString /定义布尔函数 &pendingOperator) if(pendingOperator=tr(+) sumSoFar += rightOperand; else if(pendingOperator=tr(-) sumSoFar -= rightOperand; else if(pendingOperator=tr(327) factorSoFar *= right