基于UI写的简单的计算器

</pre><span style="font-size:24px;"></span><div style="text-align: center;">主要代码</div><div style="text-align: left;">.h文件</div><div style="text-align: left;"><pre name="code" class="cpp">#import <UIKit/UIKit.h>@interface ViewController : UIViewController@property(retain,nonatomic)UIButton *button;@property(retain,nonatomic)UILabel *label;@property(retain,nonatomic)NSMutableString *string;@property(assign,nonatomic)double num1,num2,num3,num4;@end

.m文件

#import "ViewController.h"@interface ViewController ()@end@implementation ViewController@synthesize button,label,string,num1,num2,num3,num4;//string保存字符，显示数值。num1是存输入的数值，num2是存运算符前的数值，num3是运算结果，num4是判断进行何种运算- (void)viewDidLoad{    [super viewDidLoad];        //设置背景图片    NSBundle *bundle=[NSBundle mainBundle];    NSData *data=[[NSData alloc]initWithContentsOfFile:                  [bundle pathForResource:@"3" ofType:@"jpg"]];//找到NSBundle的某一资源    UIImage *img=[UIImage imageWithData:data];//创建了可用的图像对象    [self.view setBackgroundColor:[UIColor colorWithPatternImage:img]];//UIColor colorWithPatternImage:方法是把图片转化为color类型  将背景换做提供的图片        //创建标签    self.label=[[UILabel alloc]initWithFrame:CGRectMake(90, 40, 200, 50)];    [self.view addSubview:label];    self.label.backgroundColor=[UIColor clearColor];//清空背景颜色    self.label.textColor=[UIColor blueColor];//字体颜色    self.label.textAlignment =  NSTextAlignmentRight;;//字体居右    self.label.font=[UIFont systemFontOfSize:32.4];        //添加1-9数字    NSArray *array=[NSArray arrayWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9", nil];    int n=0;    for (int i=0; i<3; i++)    {        for (int j=0; j<3; j++)        {            self.button=[UIButton buttonWithType:UIButtonTypeRoundedRect];            self.button.frame=CGRectMake(30+65*j, 150+65*i, 60, 60);            self.button.backgroundColor = [UIColor whiteColor];            [self.button setTitle:[array objectAtIndex:n++] forState:UIControlStateNormal];            self.button.titleLabel.font = [UIFont systemFontOfSize:30];            self.button.layer.cornerRadius = 6;            [self.view addSubview:button];            [self.button setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];            [self.button addTarget:self action:@selector(one:) forControlEvents:UIControlEventTouchUpInside];        }    }    //单独添加0    UIButton *button0=[UIButton buttonWithType:UIButtonTypeRoundedRect];        [button0 setFrame:CGRectMake(30, 345, 60, 60)];    button0.layer.cornerRadius = 6;    button0.backgroundColor = [UIColor whiteColor];    [button0 setTitle:@"0" forState:UIControlStateNormal];    button0.titleLabel.font = [UIFont systemFontOfSize:30];    [button0 setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];    [button0 addTarget:self action:@selector(one:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:button0];            //添加运算符    NSArray *array1=[NSArray arrayWithObjects:@"+",@"-",@"*",@"/",nil];    for (int i=0; i<4; i++)    {        UIButton *button1=[UIButton buttonWithType:UIButtonTypeRoundedRect];        [button1 setFrame:CGRectMake(225, 150+65*i, 60, 60)];        button1.backgroundColor = [UIColor whiteColor];        button1.layer.cornerRadius = 6;        [button1 setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];        [button1 setTitle:[array1 objectAtIndex:i] forState:UIControlStateNormal];        [self.view addSubview:button1];        button1.titleLabel.font = [UIFont systemFontOfSize:30];        [button1 addTarget:self action:@selector(two:) forControlEvents:UIControlEventTouchUpInside];    }        //添加=        UIButton *button2=[UIButton buttonWithType:UIButtonTypeRoundedRect];    button2.backgroundColor = [UIColor whiteColor];    [button2 setFrame:CGRectMake(160, 410, 125, 35)];    [button2 setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];    button2.titleLabel.font = [UIFont systemFontOfSize:30];    [button2 setTitle:@"=" forState:UIControlStateNormal];    button2.layer.cornerRadius = 6;    [button2 addTarget:self action:@selector(go:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:button2];        //添加清除键        UIButton *button3=[UIButton buttonWithType:UIButtonTypeRoundedRect];    button3.backgroundColor = [UIColor whiteColor];    [button3 setFrame:CGRectMake(30, 410, 125, 35)];    button3.layer.cornerRadius = 6;    [button3 setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];    [button3 setTitle:@"AC" forState:UIControlStateNormal];    button3.titleLabel.font = [UIFont systemFontOfSize:20];    [button3 addTarget:self action:@selector(clean:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:button3];        //添加.        UIButton *button4=[UIButton buttonWithType:UIButtonTypeRoundedRect];    [button4 setFrame:CGRectMake(95, 345, 60, 60)];    [button4 setTitle:@"." forState:UIControlStateNormal];    button4.titleLabel.font = [UIFont systemFontOfSize:30];    button4.layer.cornerRadius = 6;    [button4 setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];    button4.backgroundColor = [UIColor whiteColor];    [button4 addTarget:self action:@selector(one:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:button4];        //后退        UIButton *button5=[UIButton buttonWithType:UIButtonTypeRoundedRect];    [button5 setFrame:CGRectMake(160, 345, 60, 60)];    [button5 setTitle:@"back" forState:UIControlStateNormal];    button5.backgroundColor = [UIColor whiteColor];    button5.layer.cornerRadius = 6;    [button5 setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];    button5.titleLabel.font = [UIFont systemFontOfSize:20];    [button5 addTarget:self action:@selector(back:) forControlEvents:UIControlEventTouchUpInside];        [self.view addSubview:button5];            self.string=[[NSMutableString alloc]init];//初始化可变字符串，分配内存    // Do any additional setup after loading the view, typically from a nib.}-(void)one:(id)sender{    //保证是符号时在输入数字时隐藏    if ([self.string hasPrefix:@"+"]||[self.string hasPrefix:@"-"]||[self.string hasPrefix:@"*"]||[self.string hasPrefix:@"/"])//判断是否为运算符    {        [self.string setString:@""];//字符串清零    }    [self.string appendString:[sender currentTitle]];//数字连续输入    self.label.text=[NSString stringWithString:string];//显示数值    self.num1=[self.label.text doubleValue];//保存输入的数值    NSLog(@"%f",self.num1);    }-(void)two:(id)sender{    [self.string setString:@""];//字符串清零    [self.string appendString:[sender currentTitle]];    self.label.text=[NSString stringWithString:string];        //判断输入是+号    if ([self.string hasPrefix:@"+"])//hasPrefix:判断字符串以加号开头    {        self.num2=self.num1;//将前面的数值保存在num2里        self.num4=1;    }    //判断输入是-号    else if([self.string hasPrefix:@"-"])//hasPrefix:判断字符串以减号开头    {        self.num2=self.num1;        self.num4=2;    }    //判断输入是*号    else if([self.string hasPrefix:@"*"])//hasPrefix:判断字符串以乘号开头    {        self.num2=self.num1;        self.num4=3;    }    //判断输入是/号    else if([self.string hasPrefix:@"/"])//hasPrefix:判断字符串以除号开头    {        self.num2=self.num1;        self.num4=4;    }}-(void)go:(id)sender{    //判断输入是+号    if (self.num4==1)    {        self.num3=self.num2+[self.label.text doubleValue];//[self.label.text doubleValue]是每次后输入的数字        self.label.text=[NSString stringWithFormat:@"%g",self.num3];//显示结果        self.num1=[self.label.text doubleValue];//为了可以连加。保存结果        self.num3=0;        [self.string setString:@""];//保证每次结果正确输出后，再次计算，不用按清除键    }    //判断输入是-号    else if(self.num4==2)    {        self.num3=self.num2-[self.label.text doubleValue];        self.label.text=[NSString stringWithFormat:@"%g",self.num3];        self.num1=[self.label.text doubleValue];        self.num3=0;        [self.string setString:@""];    }    //判断输入是*号    else if(self.num4==3)    {        self.num3=self.num2*[self.label.text doubleValue];        self.label.text=[NSString stringWithFormat:@"%g",self.num3];        self.num1=[self.label.text doubleValue];        self.num3=0;        [self.string setString:@""];    }    //判断输入是/号    else if(self.num4 == 4)    {        self.num3=self.num2/[self.label.text doubleValue];        self.label.text=[NSString stringWithFormat:@"%g",self.num3];//计算结果显示出来        self.num1=[self.label.text doubleValue];//把计算的结果保存一下        self.num3=0;        [self.string setString:@""];    }}//当按下清除建时，所有数据清零-(void)clean:(id)sender{    [self.string setString:@""];//清空字符串    self.num3=0;    self.num2 = 0;    self.label.text=@"";//保证下次输入时清零    }//返回键-(void)back:(id)sender{    if ([self.label.text length] > 0) {        self.label.text = [self.label.text substringToIndex:[self.label.text length] - 1];    }}- (void)viewDidUnload{    [super viewDidUnload];    // Release any retained subviews of the main view.}- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);}@end

运行效果: