iOS实现简单计算器小功能

//
//  simplecaculatorviewcontroller.h
//  simplecaculator
//
//  created by li junui on 14-2-12.
//  copyright (c) 2014年 lee junhui. all rights reserved.
//
 
#import <uikit/uikit.h>
 
@interface simplecaculatorviewcontroller : uiviewcontroller
@property (weak, nonatomic) iboutlet uilabel *displayscreen;
- (ibaction)numberbtnclick:(uibutton *)sender;
- (ibaction)cleards:(uibutton *)sender;
- (ibaction)caculate:(uibutton *)sender;
- (ibaction)hint:(uibutton *)sender;
- (ibaction)act:(uibutton *)sender;
- (ibaction)clearback:(uibutton *)sender;
 
 
 
@property(assign, nonatomic) bool isuserinputingnumber;
@property(assign, nonatomic) int num1;
@property(assign, nonatomic) int num2;
@property(assign, nonatomic) int tagforact;
 
@end

//
//  simplecaculatorviewcontroller.m
//  simplecaculator
//
//  created by li junui on 14-2-12.
//  copyright (c) 2014年 lee junhui. all rights reserved.
//
 
#import "simplecaculatorviewcontroller.h"
 
@interface simplecaculatorviewcontroller ()
 
@end
 
@implementation simplecaculatorviewcontroller
 
//记录数字按钮点击事件
- (ibaction)numberbtnclick:(uibutton *)sender {
    
    if(self.isuserinputingnumber){
        int re = [_displayscreen.text intvalue] * 10 + [sender.currenttitle intvalue];
        _displayscreen.text = [nsstring stringwithformat:@"%d",re];
    } else{
        [_displayscreen settext:sender.currenttitle];
        _isuserinputingnumber = yes;//因为第一次进入程序会输入数字，因此为yes
    }
}
 
//清零操作
- (ibaction)cleards:(uibutton *)sender {
    
    _displayscreen.text = @"0";
    _isuserinputingnumber = no;//表示没有再输入了
}
 
//得到结果
- (ibaction)caculate:(uibutton *)sender {
    int re = 0;
    _num2 = [_displayscreen.text intvalue];
    switch (_tagforact) {
        case 1: //加法
            re = _num1 + _num2;
            break;
        case 2: //减法
            re = _num1 - _num2;
            break;
        case 3: //乘法
            re = _num1 * _num2;
            break;
        case 4: //除法
            re = _num1 / _num2;
            break;
    }
    _displayscreen.text = [nsstring stringwithformat:@"=%d", re];
    _num1 = 0;
    _num2 = 0;
}
 
//弹出提示对话框
- (ibaction)hint:(uibutton *)sender {
    uialertview *alert = [[uialertview alloc] initwithtitle:@"温馨提示" message:@"本计算器由ljh出品" delegate:self cancelbuttontitle:@"返回" otherbuttontitles: nil];
    [alert show];
}
 
//进行四则运算
- (ibaction)act:(uibutton *)sender {
    //1.得到_displayscreen上的数字
    _num1 = [_displayscreen.text intvalue];
    _displayscreen.text = sender.currenttitle;
    _isuserinputingnumber =yes;
    switch (sender.tag) {
        case 1: //加法
            _tagforact = 1;
            break;
        case 2: //减法
            _tagforact = 2;
            break;
        case 3: //乘法
            _tagforact = 3;
            break;
        case 4: //除法
            _tagforact = 4;
            break;
    }
}
 
//进行回删操作
- (ibaction)clearback:(uibutton *)sender {
    int length = [_displayscreen.text length];
    int temp = [_displayscreen.text intvalue];
    temp = temp/length;
}
@end