iOS小型计算器

//

//  ViewController.m

//  计算器

//屏幕的宽和高

#define SCREEN_W self.view.frame.size.width

#define SCREEN_H self.view.frame.size.height

#import "ViewController.h"

@interface ViewController ()

//用于存储输入的第一个数字

@property (nonatomic,assign) CGFloat num1;

//用于存储输入的第二个数字

@property (nonatomic,assign) CGFloat num2;

//用于存储最终结果

@property (nonatomic,assign)  CGFloat numResult;

//用于判断符号的标记

@property (nonatomic,assign) NSInteger tag;

//显示屏

@property (nonatomic,strong) UILabel *screen;

//

@property (nonatomic,strong) NSMutableString *str;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    //开辟空间

    _str = [[NSMutableString alloc]init];

    // Do any additional setup after loading the view, typically from a nib.

#pragma mark - screen

    //先创建一个标签，用于显示

    _screen = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, SCREEN_W, SCREEN_H-400-5*10)];

    //设置屏幕的字体颜色

    [_screen setTextColor:[UIColor whiteColor]];

    //设置屏幕的背景颜色

    _screen.backgroundColor = [UIColor blackColor];

    //设置屏幕的字体大小

    _screen.font = [UIFont systemFontOfSize:40];

    //设置屏幕的字体自适应

    _screen.adjustsFontSizeToFitWidth = YES;

    //设置字体的对齐方式

    _screen.textAlignment = NSTextAlignmentRight;

    //清零

    _screen.text = [NSMutableString stringWithString:@"0"];

    [self.view addSubview:_screen];

#pragma mark - buttonwith+_*/

    NSArray *signArr = @[@"÷",@"x",@"-",@"+"];

    for (int i = 0; i < [signArr count]; i++) {

        UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];

        //设置按钮的文字

        [btn setTitle:signArr[i] forState:UIControlStateNormal];

        //设置按钮的位置和大小

        btn.frame = CGRectMake(((SCREEN_W-30)/4.0)*3.0+30, _screen.frame.size.height+90*(i%4)+10, (SCREEN_W-30)/4.0, 80);

        //设置按钮的背景颜色

        btn.backgroundColor = [UIColor orangeColor];

        //设置按钮字体的大小

        btn.titleLabel.font = [UIFont systemFontOfSize:40];

        //给每个按钮添加事件

        [btn addTarget:self action:@selector(calculate:) forControlEvents:UIControlEventTouchUpInside];

        [self.view addSubview:btn];

    }

#pragma mark - 单独添加“＝”

    UIButton *goBtn = [UIButton buttonWithType:UIButtonTypeSystem];

    //设置按钮的大小和位置

    goBtn.frame = CGRectMake(((SCREEN_W-30)/4.0)*3.0+30, _screen.frame.size.height+90*4+10, (SCREEN_W-30)/4.0, 80);

    //设置按钮的背景颜色

    goBtn.backgroundColor = [UIColor orangeColor];

    //设置按钮的文字

    [goBtn setTitle:@"=" forState:UIControlStateNormal];

    //设置文字的大小

    goBtn.titleLabel.font = [UIFont systemFontOfSize:40];

    //为每个按钮添加事件

    [goBtn addTarget:self action:@selector(go:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:goBtn];

#pragma mark - number

    NSArray *numArr = @[@"7",@"8",@"9",@"4",@"5",@"6",@"1",@"2",@"3"];

    for (int i = 0 ; i < [numArr count]; i++) {

        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];

        //设置按钮的大小和位置

        btn.frame = CGRectMake(((SCREEN_W-30)/4.0+10)*(i%3), _screen.frame.size.height+90*(i/3)+90+10, (SCREEN_W-30)/4.0, 80);

        //设置按钮的背景颜色

        btn.backgroundColor = [UIColor lightGrayColor];

        //设置按钮的文字

        [btn setTitle:numArr[i] forState:UIControlStateNormal];

        //设置文字的大小

        btn.titleLabel.font = [UIFont systemFontOfSize:40];

        //设置文字的颜色

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

        //为每个按钮添加事件

        [btn addTarget:self action:@selector(expressNum:) forControlEvents:UIControlEventTouchUpInside];

        [self.view addSubview:btn];

    }

#pragma mark - 添加清除键

    UIButton *cleanBtn = [UIButton buttonWithType:UIButtonTypeCustom];

    //设置按钮的大小和位置

    cleanBtn.frame = CGRectMake(0, _screen.frame.size.height+10, (SCREEN_W-30)/4.0, 80);

    //设置按钮的背景颜色

    cleanBtn.backgroundColor = [UIColor lightGrayColor];

    //设置按钮的文字

    [cleanBtn setTitle:@"AC" forState:UIControlStateNormal];

    //设置文字的大小

    cleanBtn.titleLabel.font = [UIFont systemFontOfSize:40];

    //设置文字的颜色

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

    //为每个按钮添加事件

    [cleanBtn addTarget:self action:@selector(clean:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:cleanBtn];

#pragma mark - 单独添加0

    UIButton *btn0 = [UIButton buttonWithType:UIButtonTypeCustom];

    //设置按钮的大小和位置

    btn0.frame = CGRectMake(0, SCREEN_H - 80, (SCREEN_W-30)/4.0*2+10, 80);

    //设置按钮的背景颜色

    btn0.backgroundColor = [UIColor lightGrayColor];

    //设置按钮的文字

    [btn0 setTitle:@"0" forState:UIControlStateNormal];

    //设置文字的大小

    btn0.titleLabel.font = [UIFont systemFontOfSize:40];

    //设置文字的颜色

    [btn0 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];

    //为每个按钮添加事件

    [btn0 addTarget:self action:@selector(expressNum:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btn0];

#pragma mark - 单独添加百分号%

    UIButton *btnPrecent = [UIButton buttonWithType:UIButtonTypeCustom];

    //设置按钮的大小和位置

    btnPrecent.frame = CGRectMake(((SCREEN_W-30)/4.0+10)*2, _screen.frame.size.height+10, (SCREEN_W-30)/4.0, 80);

    //设置按钮的背景颜色

    btnPrecent.backgroundColor = [UIColor lightGrayColor];

    //设置按钮的文字

    [btnPrecent setTitle:@"%" forState:UIControlStateNormal];

    //设置文字的大小

    btnPrecent.titleLabel.font = [UIFont systemFontOfSize:40];

    //设置文字的颜色

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

    //为每个按钮添加事件

    [btnPrecent addTarget:self action:@selector(precent:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btnPrecent];

#pragma mark - 单独添加点"."

    UIButton *btnPoint = [UIButton buttonWithType:UIButtonTypeCustom];

    //设置按钮的大小和位置

    btnPoint.frame = CGRectMake(btn0.frame.size.width+10, SCREEN_H-80, (SCREEN_W-30)/4.0, 80);

    //设置按钮的背景颜色

    btnPoint.backgroundColor = [UIColor lightGrayColor];

    //设置按钮的文字

    [btnPoint setTitle:@"." forState:UIControlStateNormal];

    //设置文字的大小

    btnPoint.titleLabel.font = [UIFont systemFontOfSize:40];

    //设置文字的颜色

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

    //为每个按钮添加事件

    [btnPoint addTarget:self action:@selector(expressNum:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btnPoint];

#pragma mark - 单独添加点"+/-"

    UIButton *btnSign = [UIButton buttonWithType:UIButtonTypeCustom];

    //设置按钮的大小和位置

    btnSign.frame = CGRectMake(cleanBtn.frame.size.width+10, _screen.frame.size.height+10, (SCREEN_W-30)/4.0, 80);

    //设置按钮的背景颜色

    btnSign.backgroundColor = [UIColor lightGrayColor];

    //设置按钮的文字

    [btnSign setTitle:@"+/-" forState:UIControlStateNormal];

    //设置文字的大小

    btnSign.titleLabel.font = [UIFont systemFontOfSize:40];

    //设置文字的颜色

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

    //为每个按钮添加事件

    [btnSign addTarget:self action:@selector(signNum:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btnSign];

}

-(void) expressNum:(UIButton *)sender

{

    //先判断首字母是不是符号

    if ([_str hasPrefix:@"+"]||[_str hasPrefix:@"-"]||[_str hasPrefix:@"x"]||[_str hasPrefix:@"÷"]) {

        //如果是，就清零

        _str = [NSMutableString stringWithString:@""];

    }

    //连续追加数字

    [_str appendString:sender.currentTitle];

    _screen.text = [NSString stringWithString:_str];

    //将输入的第一个数字保存在num1中

    _num1 = [_screen.text doubleValue];

    //用于调试

    //NSLog(@"-----%ld",_num1);

}

//判断符号

-(void)calculate:(UIButton *)sender

{

    //先清零

    _str = [NSMutableString stringWithString:@""];

    //再重新追加符号

    [_str appendString:sender.currentTitle];

    //显示（这个可写可不写）

    _screen.text = [NSString stringWithString:_str];

    if ([_str hasPrefix:@"+"]) {

        _num2 = _num1;

        _tag = 1;

    }else if ([_str hasPrefix:@"-"]){

        _num2 = _num1;

        _tag = 2;

    }else if ([_str hasPrefix:@"x"]) {

        _num2 = _num1;

        _tag = 3;

    }else if ([_str hasPrefix:@"÷"]) {

        _num2 = _num1;

        _tag = 4;

    }

}

//计算结果

-(void)go:(UIButton *)sender

{

    switch (_tag) {

        case 1:

            _numResult = _num2 + _num1;

            break;

        case 2:

            _numResult = _num2 - _num1;

            break;

        case 3:

            _numResult = _num2 * _num1;

            break;

        case 4:

            _numResult = _num2 / _num1;

            break;

    }

    _screen.text = [NSString stringWithFormat:@"%lg",_numResult];

    _num1 = _numResult;

}

//清除

-(void)clean:(UIButton *)sender

{

    _str = [NSMutableString stringWithString:@""];

    _screen.text = @"0";

    _num1 = 0;

    _num2 = 0;

    _numResult = 0;

}

//百分号

-(void)precent:(UIButton *)sender

{

    _num1 = _num1 * 0.01;

    //注意，这里要以最简形式（占用宽度最小）输出，并且不会输出无意义的0

    _screen.text = [NSString stringWithFormat:@"%lg",_num1];

}

//正负号

-(void)signNum:(UIButton *)sender

{

    //先判断数字是否大于0,如果是，就变负

    if (_num1 >= 0) {

        //添加负号

        [_str insertString:@"-" atIndex:0];

        _num1 = [_str doubleValue];

        _screen.text = [NSString stringWithFormat:@"%lg",_num1];

    }

    //如果数字小于0,那么变为正数

    else if (_num1 < 0)

    {

        //删除负号

        [_str deleteCharactersInRange:NSMakeRange(0, 1)];

        _num1 = [_str doubleValue];

        _screen.text = [NSString stringWithFormat:@"%lg",_num1];

    }

}

- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

@end

//大家看了之后觉得哪里代码可以更加优化，或者功能上有什么补充的，麻烦评论下，感谢了🙏

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原标题：iOS小型计算器

关键词：IOS