iOS 计算器

@interface ViewController ()

@property (nonatomic, strong) UILabel *label;

@property (nonatomic, strong) NSString *operator1;

@property (nonatomic, strong) NSString *operator2;

@property (nonatomic, strong) NSString *operand;

@end

@implementation ViewController

- (void)viewDidLoad

{

[super viewDidLoad];

[self createCalculator];

}

- (void)createCalculator

{

self.operand = self.operator1 = self.operator2 = @"";



self.label = [[UILabel alloc] initWithFrame:CGRectMake(10, 40, self.view.bounds.size.width-20, 60)];

self.label.backgroundColor = [UIColor grayColor];

self.label.layer.cornerRadius = 5;

self.label.numberOfLines = 2;

self.label.textAlignment = NSTextAlignmentRight;

[self.view addSubview:self.label];



// 第一行按钮

CGRect frame = CGRectZero;

NSArray *titles0 = @[@"MC", @"M+", @"M-", @"MR", @"清除"];

CGFloat padding = 10;

CGFloat buttonWidth = (self.view.bounds.size.width-(titles0.count+1)*padding)/titles0.count;

CGFloat buttonHeight = 50;

for (int i = 0; i < titles0.count; i++) {

frame = CGRectMake(padding+i*(padding+buttonWidth), CGRectGetMaxY(self.label.frame)+padding, buttonWidth, buttonHeight);

[self addButtonWithRect:frame title:titles0[i]];

}



// 其他按钮

NSArray *titles1 = @[@"7", @"8", @"9", @"+",

@"4", @"5", @"6", @"-",

@"1", @"2", @"3", @"*",

@"0", @".", @"=", @"/"];

buttonWidth = (self.view.bounds.size.width-5*padding)/4;

for (int i = 0; i < 4; i++) {

for (int j = 0; j < 4; j++) {

[self addButtonWithRect:CGRectMake(padding+j*(padding+buttonWidth), CGRectGetMaxY(frame) + padding + i*(padding+buttonHeight), buttonWidth, buttonHeight) title:titles1[i*4+j]];

}

}

}

- (void)addButtonWithRect:(CGRect)rect title:(NSString *)title

{

UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];

button.frame = rect;

button.backgroundColor = [UIColor grayColor];

button.layer.cornerRadius = 10;

[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

[button setTitle:title forState:UIControlStateNormal];

[button addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button];

}

- (void)buttonClick:(UIButton *)button

{

// 以M开头的按钮不处理

if ([button.titleLabel.text hasPrefix:@"M"]) {

return;

}



// 清除按钮被点击

if ([button.titleLabel.text isEqualToString:@"清除"]) {

self.operand = @"";

self.operator1 = @"";

self.operator2 = @"";

self.label.text = @"";

return;

}



NSString *strInput = button.titleLabel.text;



if ([self isOperand:strInput]) { // 如果是运算符

if (self.operand.length) { // 如果当前已经有一个操作符了，则对当前的两个操作数进行运算

float result;

float operator1 = [_operator1 floatValue];

float operator2 = [_operator2 floatValue];

if ([self.operand isEqualToString:@"+"]) {

result = operator1 + operator2;

} else if ([_operand isEqualToString:@"-"]) {

result = operator1 - operator2;

} else if ([_operand isEqualToString:@"*"]) {

result = operator1 * operator2;

} else if ([_operand isEqualToString:@"/"]) {

result = operator1 / operator2;

}



self.operator1 = [NSString stringWithFormat:@"%0.2f", result];

self.operator2 = @"";



if ([strInput isEqualToString:@"="]) {

self.operand = @"";

} else {

self.operand = strInput;

}

self.label.text = self.operator1;

} else {

self.operand = strInput;

}

} else { // 不是运算符，是操作数

if (self.operand.length) { // 当前有操作符，这是第二操作数

self.operator2 = [self.operator2 stringByAppendingString:strInput];

} else {

self.operator1 = [self.operator1 stringByAppendingString:strInput];

}

}



if (_operator2.length) {

_label.text = [NSString stringWithFormat:@"%@\n%@", _operator2, _operand];

} else {

_label.text = [NSString stringWithFormat:@"%@\n%@", _operator1, _operand];

}

}

// 判断参数str是否为运算符

// 返回值为TRUE代表是运算符，FALSE代表不是运算符

- (BOOL)isOperand:(NSString *)str

{

NSRange range = [str rangeOfCharacterFromSet:[NSCharacterSet characterSetWithCharactersInString:@"+-*/="]];

if (range.location != NSNotFound) {

return YES;

}

return NO;

}

@end