iOS:制作一个简易的计算器

初步接触视图,制作了一个简易的计算器,基本上简单的计算是没有问题的，不是很完美,可能还有一些bug,再接再厉。

 //
 //  ViewController.m
 //  计算器
 //
 //  Created by ma c on 15/8/25.
 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 //

 #import "ViewController.h"

 @interface ViewController ()
 @property (weak, nonatomic) IBOutlet UITextField *ResultField;
 @property(nonatomic,assign)CGFloat temp;
 @property(nonatomic,assign)CGFloat num1;
 @property(nonatomic,assign)CGFloat num2;
 @property(nonatomic,strong)NSMutableString *string;
 @property(nonatomic,strong)NSArray *arr;
 @end
 @implementation ViewController
 - (IBAction)buttonClear:(UIButton *)sender
 {
     [_string setString:@""];         //重新开始计算,文本框置空
     self.ResultField.text = _string;
 }
 - (IBAction)button7:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button8:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button9:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button4:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button5:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button6:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button1:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button3:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button2:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }
 - (IBAction)button0:(UIButton *)sender
 {
     [_string appendString:@""];
     self.ResultField.text = _string;
 }

 - (IBAction)buttonPoint:(UIButton *)sender
 {
     [_string appendString:@"."];
     self.ResultField.text = _string;
 }

 //触发算数运算事件
 - (IBAction)buttonDiv:(UIButton *)sender
 {
     [_string appendString:@"/"];
     self.ResultField.text = _string;
 }

 - (IBAction)buttonMul:(UIButton *)sender
 {
     [_string appendString:@"*"];
     self.ResultField.text = _string;
 }

 - (IBAction)buttonSub:(UIButton *)sender
 {
     [_string appendString:@"-"];
     self.ResultField.text = _string;
 }

 - (IBAction)buttonAdd:(UIButton *)sender
 {
     [_string appendString:@"+"];
     self.ResultField.text = _string;
 }

 //做结果运算操作
 - (IBAction)buttonEqual:(UIButton *)sender
 {

     for(int i=; i<[_string length]; i++)
     {

         self.arr = [[NSArray alloc]init];

         //只输入一个数,不做运算
         if([_string length] == )
         {
             self.temp = [_string doubleValue];
             break;
         }

         //做加法运算
         if([_string characterAtIndex:i] == '+')
         {
             self.arr = [_string componentsSeparatedByString:@"+"];

             self.num1 = [self.arr[] doubleValue];
             self.num2 = [self.arr[] doubleValue];
             self.temp = self.num1 + self.num2;
             break;
         }

         //做减法运算
         if([_string characterAtIndex:(i+)] == '-')
         {
             self.arr = [_string componentsSeparatedByString:@"-"];

             if([self.arr count] == )
             {
                 self.num1 = [self.arr[] doubleValue];
                 self.num2 = [self.arr[] doubleValue];
                 self.temp = self.num1 - self.num2;
             }
             else
             {
                 self.num1 = [self.arr[] doubleValue];
                 self.num2 = [self.arr[] doubleValue];
                 self.temp = -(self.num1 + self.num2);
             }
             break;
         }

         //做除法运算
         if([_string characterAtIndex:i] == '/')
         {
             self.arr = [_string componentsSeparatedByString:@"/"];
             self.num1 = [self.arr[] doubleValue];
             self.num2 = [self.arr[] doubleValue];
             self.temp = self.num1 / self.num2;
             break;
         }

         //做乘法运算
         if([_string characterAtIndex:i] == '*')
         {
             self.arr = [_string componentsSeparatedByString:@"*"];
             self.num1 = [self.arr[] doubleValue];
             self.num2 = [self.arr[] doubleValue];
             self.temp = self.num1 * self.num2;
             break;
         }

     }

     //输出结果
     [_string setString:[NSString stringWithFormat:@"%.2f",self.temp]];
     self.ResultField.text = _string;
 }

 - (void)viewDidLoad {
     [super viewDidLoad];

     //创建一个可变的字符串
     _string = [NSMutableString stringWithCapacity:];
 }

 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

 @end