iOS计算器的代码实现详解手机开发

-(void)viewDidLoad 
 
{ 
 
    //初始化字符串 
 
    self.num1 = [[NSMutableString alloc]init]; 
 
    self.num2 = [[NSMutableString alloc]init]; 
 
    self.tempStr = [[NSMutableString alloc]init]; 
 
  
 
     
 
} 
 
//监听数字按钮0-9和点，点的tag为10 
 
//判断输入数字前有几个0，只取一个零，小数点只取一个 
 
-(IBAction)numbers:(id)sender 
 
{ 
 
    //处理0的问题 
 
    //以零开头，下次输入的非0，则清空0 
 
     //如果以0.开头，则不清空 
 
    if ([self.tempStr hasPrefix:@"0"] && [sender tag] > 0 && [sender tag] <10 && ![self.tempStr hasPrefix:@"0."]) 
 
    { 
 
        self.tempStr = [NSMutableString stringWithString:@""]; 
 
    } 
 
    else if ([self.tempStr hasPrefix:@"0"] && [sender tag] == 0 && ![self.tempStr hasPrefix:@"0."]) 
 
    { 
 
        //如果是以0开头，但是不是以0.开头，则直接返回 
 
        return; 
 
        
 
   } 
 
     
 
    //处理小数点的问题 
 
    //如果小数点是第一输入的数字 
 
    if ([sender tag] == 10 && self.tempStr.length == 0) 
 
    { 
 
        self.tempStr = [NSMutableString stringWithString:@"0"]; 
 
    } 
 
        //每输入一次，拼接一次字符串 
 
    if([sender tag] == 10 )//取小数点 
 
    { 
 
        //小数点只允许输入一次 
 
        //遍历字符串tempStr，如果有小数点，则直接return 
 
        for (int i = 0; i < self.tempStr.length ; i++) 
 
        { 
 
            char c = [self.tempStr characterAtIndex:i]; 
 
            if (c == '.') 
 
            { 
 
                return; 
 
            } 
 
        } 
 
         [self.tempStr appendString:@"."]; 
 
    } 
 
    else 
 
    { 
 
         [self.tempStr appendFormat:@"%ld",[sender tag]]; 
 
    } 
 
    _show.text = self.tempStr; 
 
} 
 
//删除按钮 
 
-(IBAction)deleteNums:(id)sender 
 
{ 
 
    if (_show.text.length == 1)//删除显示屏中所有的数字 
 
    { 
 
        _show.text = @"0"; 
 
        //清空tempStr 
 
        self.tempStr = [NSMutableString stringWithString:@""]; 
 
        return; 
 
    } 
 
    //将显示屏中的现有数字赋值给字符串 
 
//    NSMutableString *str = [[NSMutableString alloc]init]; 
 
    self.tempStr =[NSMutableString stringWithFormat:@"%@", _show.text] ; 
 
    [self.tempStr deleteCharactersInRange:NSMakeRange(self.tempStr.length-1, 1)]; 
 
    _show.text = self.tempStr; 
 
} 
 
  
 
//监听加减乘除 calculate "=" 11    "+" 12      "-" 13    "*" 14    "/" 15  正负为16  %为17 
 
-(IBAction)calculate:(id)sender 
 
{ 
 
    //清空tempStr 
 
    self.tempStr = [NSMutableString stringWithString:@""]; 
 
    if(0 == _count)//如果是第一次输入 
 
    { 
 
        _cal = [NSNumber numberWithLong:[sender tag]]; 
 
        self.num1 = [NSMutableString stringWithFormat:@"%@",_show.text]; 
 
    } 
 
    else//不是第一次输入，则计算 
 
    { 
 
        self.num2 = [NSMutableString stringWithFormat:@"%@", _show.text]; 
 
        int calculate = [_cal intValue]; 
 
        switch (calculate) { 
 
            case 12://将加后的结果显示 
 
                _show.text =[NSString stringWithFormat:@"%.2f",([self.num1 doubleValue] + [self.num2 intValue])]; 
 
                break; 
 
            case 13://将减后的结果显示 
 
                _show.text =[NSString stringWithFormat:@"%.2f",([self.num1 doubleValue] - [self.num2 intValue])]; 
 
                break; 
 
            case 14://将乘后的结果显示 
 
                _show.text =[NSString stringWithFormat:@"%.2f",([self.num1 doubleValue] * [self.num2 intValue])]; 
 
                break; 
 
            case 15://将除后的结果显示 
 
                _show.text =[NSString stringWithFormat:@"%.2f",([self.num1 doubleValue] / [self.num2 intValue])]; 
 
                break; 
 
            default: 
 
                break; 
 
        } 
 
        self.num1 = [NSMutableString stringWithFormat:@"%@", _show.text]; 
 
        _cal = [NSNumber numberWithLong:[sender tag]]; 
 
    } 
 
    _count = @1; 
 
    if ([sender tag] == 16 || [sender tag] == 17)//单目运算正负和% 
 
    { 
 
        switch ([sender tag]) { 
 
            case 16://将乘负后的结果显示 
 
                _show.text =[NSString stringWithFormat:@"%.2f",([self.num1 doubleValue] *(-1))]; 
 
                break; 
 
            case 17://将取百分后的结果显示 
 
                _show.text =[NSString stringWithFormat:@"%.2f",([self.num1 doubleValue] / 100)]; 
 
                break; 
 
            default: 
 
                break; 
 
        } 
 
        self.num1 = [NSMutableString stringWithFormat:@"%@", _show.text]; 
 
    } 
 
  
 
}