这节课主要讲了MVC架构，并且根据MVC架构完成了第一个项目，计算器的开发，下面简单的记一下学习笔记，以及该项目的代码。
MVC中M指model，V指view，C指Controler，按照我的理解，M中主要就是函数库，里面定义了各种函数，完成具体的实现功能；V也就是前端的界面了，也就是swift中所见即所得的部分。C为控制器，有点像以前在c语言中用到的main函数一样。MVC之间的关系呢，界面和模型之间不会有直接的交互，它们的交流都是通过控制器为媒介，串联起来，其关系图如下：
下面主要就是MVC框架的应用了，计算器实现代码如下：
[ViewController.swift]
//
// ViewController.swift
// Calculator
//
// Created by Sergey Linnik on 10/12/16.
// Copyright © 2016 Sergey Linnik. All rights reserved.
//
import UIKit
classViewController:UIViewController{
@IBOutlet private weak var display: UILabel!
@IBOutlet private weak var history: UILabel!
private var calculatorService: CalculatorService = CalculatorService()
privatevaruserIsInProgress =false
privatevardisplayText:Double{
get{
returnDouble(display.text!)!
}
set{
display.text=String(newValue)
}
}
@IBActionprivatefunctouchDigit(_sender:UIButton) {
letdigit = sender.currentTitle!
letcurrentTitle =display.text!
if !userIsInProgress {
display.text= digit
}else{
display.text= currentTitle + digit
}
userIsInProgress = true
}
@IBActionprivatefuncperformOperation(_sender:UIButton) {
if userIsInProgress {
calculatorService.setOperand(operand: displayText)
userIsInProgress = false
}
ifletoperationType = sender.currentTitle{
calculatorService.performOperation(symbol: operationType)
}
displayText = calculatorService.result
}
@IBActionfuncmakeHistory(_sender:UIButton) {
ifhistory.text==nil{
history.text=""
}
history.text=history.text! + sender.currentTitle!
}
}
[CalculatorService.swift]
//
// CalculatorService.swift
// Calculator
//
// Created by Sergey Linnik on 10/12/16.
// Copyright © 2016 Sergey Linnik. All rights reserved.
//
importFoundation
classCalculatorService {
privatevaraccumulator =0.0
privateenumOperation {
caseConstant(Double)
caseUnaryOperation((Double) ->Double)
caseBinaryOperation((Double,Double) ->Double)
caseEquals
caseReset
}
varresult:Double{
get{
returnaccumulator
}
}
private var pending: PendingBinaryOperationInfo?
privatestructPendingBinaryOperationInfo {
varbinaryOperation: (Double,Double) ->Double
varfirstOperand:Double
}
funcsetOperand(operand:Double){
accumulator= operand
}
privatevaroperations:Dictionary = [
"AC":Operation.Reset,
"π":Operation.Constant(M_PI),
"e":Operation.Constant(M_E),
"√": Operation.UnaryOperation(sqrt),
"cos": Operation.UnaryOperation(cos),
"±":Operation.UnaryOperation({ -$0 }),
"×":Operation.BinaryOperation({$0 * $1}),
"÷":Operation.BinaryOperation({$0 / $1}),
"+":Operation.BinaryOperation({$0 + $1}),
"-":Operation.BinaryOperation({$0 - $1}),
"=":Operation.Equals,
".":Operation.BinaryOperation({Double("\($0).\($1)")! })
]
funcperformOperation(symbol:String){
ifletoperation =operations[symbol]{
switchoperation {
case.Constant(letvalue):
accumulator= value
case.UnaryOperation(letfunction):
accumulator= function(accumulator)
case.BinaryOperation(letfunction):
executePendingOperation()
pending=PendingBinaryOperationInfo(binaryOperation: function, firstOperand:accumulator)
case.Reset:
pending=nil
accumulator=0.0
case.Equals:
executePendingOperation()
default:break
}
}
}
privatefuncexecutePendingOperation() {
ifpending!=nil{
accumulator = pending!.binaryOperation(pending!.firstOperand, accumulator)
pending=nil
}
}
}