Xcode写的一个UI计算器，加减乘除等号方法怎么实现，写不下来，中间删去了几个button

Question

}- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    
    oneLabel=[[UILabel alloc]initWithFrame:CGRectMake(10, 30, 300, 50)];
    [oneLabel setTextAlignment:UITextAlignmentRight];
    oneLabel.text=@"";
    [self.window addSubview:oneLabel];
    [oneLabel release];
      oneButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    oneButton.frame=CGRectMake(10, 90, 150, 50);
    [oneButton setTitle:@"Del" forState:UIControlStateNormal];
    [oneButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [oneButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [oneButton addTarget:self action:@selector(delete:) forControlEvents:UIControlEventTouchUpInside];
     [self.window addSubview:oneButton];
        twoButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    twoButton.frame=CGRectMake(165, 90, 145,50 );
    [twoButton setTitle:@"C" forState:UIControlStateNormal];
    [twoButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [twoButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [twoButton addTarget:self action:@selector(clear) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:twoButton];
        
    sixButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    sixButton.frame=CGRectMake(235, 150, 65, 65);
    [sixButton setTitle:@"+" forState:UIControlStateNormal];
    [sixButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [sixButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [sixButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:sixButton];
    
    sevenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    sevenButton.frame=CGRectMake(10, 220, 65, 65);
    [sevenButton setTitle:@"4" forState:UIControlStateNormal];
    [sevenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [sevenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [sevenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:sevenButton];
    
    eightButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    eightButton.frame=CGRectMake(85, 220, 65, 65);
    [eightButton setTitle:@"5" forState:UIControlStateNormal];
    [eightButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [eightButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [eightButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:eightButton];
    
    nineButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    nineButton.frame=CGRectMake(160, 220, 65, 65);
    [nineButton setTitle:@"6" forState:UIControlStateNormal];
    [nineButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [nineButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [nineButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:nineButton];
    
    tenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    tenButton.frame=CGRectMake(235, 220, 65, 65);
    [tenButton setTitle:@"-" forState:UIControlStateNormal];
    [tenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [tenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [tenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:tenButton];
    
    elevenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    elevenButton.frame=CGRectMake(10, 290, 65, 65);
    [elevenButton setTitle:@"7" forState:UIControlStateNormal];
    [elevenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [elevenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [elevenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:elevenButton];
    
    twelveButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    twelveButton.frame=CGRectMake(85, 290, 65, 65);
    [twelveButton setTitle:@"8" forState:UIControlStateNormal];
    [twelveButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [twelveButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [twelveButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:twelveButton];
    
    thirteenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    thirteenButton.frame=CGRectMake(160, 290, 65, 65);
    [thirteenButton setTitle:@"9" forState:UIControlStateNormal];
    [thirteenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [thirteenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [thirteenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:thirteenButton];
    
    fourteenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    fourteenButton.frame=CGRectMake(235, 290, 65, 65);
    [fourteenButton setTitle:@"*" forState:UIControlStateNormal];
    [fourteenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [fourteenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [fourteenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:fourteenButton];
    
    
    fifteenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    fifteenButton.frame=CGRectMake(10, 360, 65, 65);
    [fifteenButton setTitle:@"." forState:UIControlStateNormal];
    [fifteenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [fifteenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [fifteenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:fifteenButton];
    
    sixteenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    sixteenButton.frame=CGRectMake(85, 360, 65, 65);
    [sixteenButton setTitle:@"0" forState:UIControlStateNormal];
    [sixteenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [sixteenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [sixteenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:sixteenButton];
    
    seventeenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    seventeenButton.frame=CGRectMake(160, 360, 65, 65);
    [seventeenButton setTitle:@"=" forState:UIControlStateNormal];
    [seventeenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [seventeenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [seventeenButton addTarget:self action:@selector(equal:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:seventeenButton];
    
    eighteenButton=[UIButton buttonWithType:UIButtonTypeRoundedRect];
    eighteenButton.frame=CGRectMake(235, 360, 65, 65);
    [eighteenButton setTitle:@"/" forState:UIControlStateNormal];
    [eighteenButton setTitleColor:[UIColor brownColor] forState:UIControlStateNormal];
    [eighteenButton.titleLabel setFont:[UIFont fontWithName:@"Arial" size:20]];
    [eighteenButton addTarget:self action:@selector(input:) forControlEvents:UIControlEventTouchUpInside];
    [self.window addSubview:eighteenButton];
    [self.window makeKeyAndVisible];
    return YES;
}
-(void)input:(id)sender
{
    NSString * nstr;
    UIButton * button=(UIButton *)sender;
    if ([oneLabel.text isEqual:@""]) {
        nstr=[[NSString alloc]initWithFormat:@"%@",button.titleLabel.text];
    }
    else {
        nstr=[oneLabel.text stringByAppendingString:button.titleLabel.text];
    }
    oneLabel.text=nstr;
     }
-(void)clear
{
           oneLabel.text=@"";
}
-(void)delete:(id)sender
{
    NSString * nstr;
    if (![oneLabel.text isEqual:@""]) {
        nstr=[oneLabel.text substringToIndex:[oneLabel.text length]-1];
    }
    else {
        nstr=@"";
    }
oneLabel.text=nstr;
}

Answer 1

#import "MCCalculatorCenter.h"@implementation MCCalculatorCenter
@synthesize operationStack=_operationStack;-(void) pushOperand:(NSString *)operand
{
    [self.operationStack addObject:operand];               //压入参数
}-(NSMutableArray*)operationStack                           //初始化指针_operationStack若为空
{
    if(_operationStack == nil)
    {
    _operationStack=[[NSMutableArray alloc] init];
    }
    return _operationStack;
}-(NSString*) popOperand
{
    NSString *operand=[self.operationStack lastObject];
    
    if(operand)
    {
    [self.operationStack removeLastObject];                //防止返回空值
    }
    return operand;
}-(double) performOperation:(NSString *)opertion
{
    double result=0.0;
    
    double secondOperand=[self popOperand].doubleValue;
    NSString *waitingOperation=[self popOperand];
    double firstOperand=[self popOperand].doubleValue;
    
    if([waitingOperation isEqualToString:@"+"])
    {
        result=firstOperand+secondOperand;
    }
    else if([waitingOperation isEqualToString:@"-"])
    {
        result=firstOperand-secondOperand;
    }
    else if([waitingOperation isEqualToString:@"*"])
    {
        result=firstOperand*secondOperand;
    }
    else if([waitingOperation isEqualToString:@"/"])
    {
        result=firstOperand/secondOperand;
    }
    else
    {
        result=secondOperand;                //等号状态
    }
    
    [self pushOperand:[NSString stringWithFormat:@"%g",result]];
    [self pushOperand:opertion];
   
    return result;
}-(void) replaceStackTopOperation:(NSString *)operation
{
    [self popOperand];
    [self pushOperand:operation];
}-(void) CleanStack
{
    [self.operationStack removeAllObjects];
}-(void)dealloc
{
    [_operationStack release];
    [super dealloc];
}@end

Answer 2

推荐使用autolayout 来布局