Inthisclass,myteacheristalkingaboutMVC
Model-View-Controller
Ithinkit’snoteasytoacceptMVCwhenyoutouchitatthefirsttime.Luckily,Ihaveknow alittleaboutit.
Beforethisclass,IthinkthatMCVisdesignforB/SFramework~ActuallyIamwrong.
NowItrytointroMVC.
Controller:TodecidewhattimetocreateaViewtopeopleandsendmessagetotheViewortheModel.
Model:Allkindsofentity-datathatwillbeusedforControllerandView.
View:TodealwiththeModelDatathencreatetheUIInterfaceforpeople.
Hereisanexample
AMainClass(MVCCalculator)andcreate3Classnamed(CalculatorController、CalculatorModel、CalculatorView)
Result:
Thereare4linesofcontrols.
SoIcreateListArray<T>toreceivethecontrols
MVCCalculator：
publicclassMVCCalculator{
publicstaticvoidmain(String[]args){
CalculatorViewtheView=newCalculatorView();
CalculatorModeltheModel=newCalculatorModel();
CalculatorControllertheController=newCalculatorController(theView,theModel);
theView.setVisible(true);
}
}
CalculatorController：
publicclassCalculatorController{
privateCalculatorViewtheView;
privateCalculatorModeltheModel;
publicCalculatorController(CalculatorViewtheView,CalculatorModeltheModel){
this.theView=theView;
this.theModel=theModel;
//TelltheViewthatwheneverthecalculatebutton
//isclickedtoexecutetheactionPerformedmethod
//intheCalculateListenerinnerclass
for(inti=0;i<4;i++)
{
this.theView.addCalculateListener(i,newCalculateListener(i));
}
}
classCalculateListenerimplementsActionListener{
intindex=-1;
privateCalculateListener(inti){
index=i;
}
publicvoidactionPerformed(ActionEvente){
intfirstNumber=0;
intsecondNumber=0;
//Surroundinteractionswiththeviewwith
//atryblockincasenumbersweren’t
//properlyentered
try{
firstNumber=theView.getFirstNumber(index);
secondNumber=theView.getSecondNumber(index);
if(index==0)
{
theModel.addTwoNumbers(firstNumber,secondNumber);
}
elseif(index==1)
{
theModel.subTwoNumbers(firstNumber,secondNumber);
}
elseif(index==2)
{
theModel.mulTwoNumbers(firstNumber,secondNumber);
}
elseif(index==3)
{
theModel.divTwoNumbers(firstNumber,secondNumber);
}
theView.setCalcSolution(index,theModel.getCalculationValue());
}
catch(NumberFormatExceptionex){
System.out.println(ex);
theView.displayErrorMessage("YouNeedtoEnter2Integers");
}
}
}
}
CalculatorModel：
publicclassCalculatorModel{
//Holdsthevalueofthesumofthenumbers
//enteredintheview
privateintcalculationValue;
publicvoidaddTwoNumbers(intfirstNumber,intsecondNumber){
calculationValue=firstNumber+secondNumber;
}
publicvoidsubTwoNumbers(intfirstNumber,intsecondNumber){
calculationValue=firstNumber-secondNumber;
}
publicvoidmulTwoNumbers(intfirstNumber,intsecondNumber){
calculationValue=firstNumber*secondNumber;
}
publicvoiddivTwoNumbers(intfirstNumber,intsecondNumber){
calculationValue=firstNumber/secondNumber;
}
publicintgetCalculationValue(){
returncalculationValue;
}
}
CalculatorView：
publicclassCalculatorViewextendsJFrame{
privateArrayList<JTextField>firstNumber=newArrayList<JTextField>();
privateArrayList<JLabel>additionLabel=newArrayList<JLabel>();
privateArrayList<JTextField>secondNumber=newArrayList<JTextField>();
privateArrayList<JButton>calculateButton=newArrayList<JButton>();
privateArrayList<JTextField>calcSolution=newArrayList<JTextField>();
CalculatorView(){
//Setsuptheviewandaddsthecomponents
ArrayList<JPanel>calcPanel=newArrayList<JPanel>();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(600,200);
this.setLayout(newGridLayout(4,1,0,0));
String[]str={"+","-","*","/"};
for(inti=0;i<4;i++)
{
firstNumber.add(newJTextField(10));
additionLabel.add(newJLabel(str[i]));
secondNumber.add(newJTextField(10));
calculateButton.add(newJButton("Calculate"));
calcSolution.add(newJTextField(10));
calcPanel.add(newJPanel());
calcPanel.get(i).add(firstNumber.get(i));
calcPanel.get(i).add(additionLabel.get(i));
calcPanel.get(i).add(secondNumber.get(i));
calcPanel.get(i).add(calculateButton.get(i));
calcPanel.get(i).add(calcSolution.get(i));
this.add(calcPanel.get(i),i);
}
//Endofsettingupthecomponents——–
}
publicintgetFirstNumber(inti){
returnInteger.parseInt(firstNumber.get(i).getText());
}
publicintgetSecondNumber(inti){
returnInteger.parseInt(secondNumber.get(i).getText());
}
publicintgetCalcSolution(inti){
returnInteger.parseInt(calcSolution.get(i).getText());
}
publicvoidsetCalcSolution(inti,intsolution){
calcSolution.get(i).setText(Integer.toString(solution));
}
//IfthecalculateButtonisclickedexecuteamethod
//intheControllernamedactionPerformed
voidaddCalculateListener(inti,ActionListenerlistenForCalcButton){
calculateButton.get(i).addActionListener(listenForCalcButton);
}
//Openapopupthatcontainstheerrormessagepassed
voiddisplayErrorMessage(StringerrorMessage) {
JOptionPane.showMessageDialog(this,errorMessage);
}
}
伟人所达到并保持着的高处，并不是一飞就到的，
