【学习中的分享】 iOS利用UILabel和UIButton制作一个简单的计算器

初学者，效果一般 ，不要见笑

#import <UIKit/UIKit.h>

@interface AppDelegate :
UIResponder <UIApplicationDelegate>
{
    UILabel *_lable;
    NSMutableString *_string;
    BOOL _flag;
}
@property (strong,
nonatomic) UIWindow *window;

@end

****************************************************************************************


#import "AppDelegate.h"
#import <Foundation/Foundation.h>
@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindowalloc]
initWithFrame:[[UIScreenmainScreen]
bounds]];
    // Override point for customization after application launch.
    UIImage *image= [UIImageimageNamed:@"123.png"];
    UIImageView *imageview=[[UIImageViewalloc]
initWithImage:image];
    imageview.frame=CGRectMake(0,20,
320, 480);
    [self.window
addSubview:imageview];
    [imageview release];

    _string = [[NSMutableStringalloc]init];
    _flag = YES;
    _lable = [[UILabelalloc]initWithFrame:CGRectMake(10,20,
300,100)];
    _lable.textAlignment =NSTextAlignmentRight;
    _lable.textColor=[UIColorgreenColor];
    _lable.font=[UIFontsystemFontOfSize:25];
    _lable.backgroundColor = [UIColorclearColor];
    [self.windowaddSubview:_lable];
    NSArray *array = [NSArrayarrayWithObjects:@"MC",@"M+",@"M-",@"MR",@"清除",nil];
    for(int i =
0;i < 5; i++)
    {
        UIButton *button = [UIButtonbuttonWithType:UIButtonTypeRoundedRect];
        button.frame = CGRectMake(i*60+11,120,
58, 30);
        button.backgroundColor = [UIColorwhiteColor];
        button.titleLabel.font = [UIFontsystemFontOfSize:20];
        [button setTitleColor:[UIColorredColor]
forState:UIControlStateNormal];
        [button setTitleColor:[UIColorgreenColor]
forState:UIControlStateHighlighted];
        button.backgroundColor = [UIColorclearColor];
        button.showsTouchWhenHighlighted=YES;
        [button setTitle:array[i]forState:UIControlStateNormal];
        [self.windowaddSubview:button];
        if(i == 4)
        [button addTarget:selfaction:@selector(subCharToString)forControlEvents:UIControlEventTouchUpInside];
    }
    array = [NSArrayarrayWithObjects:@"7",@"8",@"9",@"+",@"4",@"5",@"6",@"-",@"1",@"2",@"3",@"*",@"0",@".",@"=",@"/",nil];
    int value[] = {7,8,9,10,4,5,6,10,1,2,3,10,0,10,10,10};
    for(int i =
0;i < 4; i++){
        for(int j =0;j <
4; j++){
            UIButton *button = [UIButtonbuttonWithType:UIButtonTypeRoundedRect];
            button.frame =
CGRectMake(j*75+10, i*40+150,74,
39);
            [button setTitle:array[4*i+j]forState:UIControlStateNormal];
            if(i == 3 && j ==2)
                [button addTarget:selfaction:@selector(calCharToString)forControlEvents:UIControlEventTouchUpInside];
            else
                [button addTarget:selfaction:@selector(addCharToString:)forControlEvents:UIControlEventTouchUpInside];
            button.tag = value[4*i+j];
            button.titleLabel.font = [UIFontsystemFontOfSize:25];
            button.backgroundColor=[UIColorclearColor];
            button.showsTouchWhenHighlighted =YES;
            [self.windowaddSubview:button];
            if(i == 3 && j ==2)
                [button addTarget:selfaction:@selector(calCharToString)forControlEvents:UIControlEventTouchUpInside];
        }
    }
        self.window.backgroundColor = [UIColorwhiteColor];
    
    [self.windowmakeKeyAndVisible];
    return YES;
}

- (void)calCharToString
{
    //- (NSInteger)calcString:(NSString *)mathString
    _lable.text = [NSStringstringWithFormat:@"%d",[selfcalcString:_string]];
    //[_string deleteCharactersInRange:NSMakeRange(0, _string.length-1)];
    [_stringreplaceCharactersInRange:NSMakeRange(0,_string.length)withString:_lable.text];
    _flag = YES;
}
- (BOOL)isNumber:(unichar)c
{
    if (c<='9'&&c>='0')
        return YES;
    else
        return NO;
}

- (NSInteger)calcString:(NSString *)mathString
{
    NSMutableArray * array = [[NSMutableArrayalloc]init];
    NSMutableArray * array1 = [[NSMutableArrayalloc]init];
    NSString * str = [NSStringstringWithFormat:@"%@ ",mathString];
    int len = 0, loc =0;
    for (int i =
0; i < str.length; i++) {
        if (![self
isNumber:[str characterAtIndex:i]]) {
            [array addObject:[str
substringWithRange:NSMakeRange(loc, len)]];
            [array1 addObject:[strsubstringWithRange:NSMakeRange(i,1)]];
            len = 0;
            loc = i+1;
        }else{
            len++;
        }
    }
    if (!([array[0]length])) {
        [array removeObjectAtIndex:0];
        [array insertObject:[NSStringstringWithFormat:@"%d",0]atIndex:0];
    }
    while ([array1 containsObject:@"*"]||[array1containsObject:@"/"]) {
        NSUInteger index = [array1
indexOfObject:@"*"];
        NSUInteger index2 = [array1
indexOfObject:@"/"];
        if (index < index2) {
            int a = [[array
objectAtIndex:index]intValue];
            int b = [[array
objectAtIndex:index+1]intValue];
            a = a * b;
            [array1 removeObjectAtIndex:index];
            [array removeObjectAtIndex:index];
            [array removeObjectAtIndex:index];
            [array insertObject:[NSStringstringWithFormat:@"%d",a]
atIndex:index];
        }
        else
        {
            int a = [[array
objectAtIndex:index2]intValue];
            int b = [[array
objectAtIndex:index2+1]intValue];
            a = a / b;
            [array1 removeObjectAtIndex:index2];
            [array removeObjectAtIndex:index2];
            [array removeObjectAtIndex:index2];
            [array insertObject:[NSStringstringWithFormat:@"%d",a]
atIndex:index2];
            
        }
    }
    while ([array1 containsObject:@"+"]||[array1containsObject:@"-"]) {
        NSUInteger index = [array1
indexOfObject:@"+"];
        NSUInteger index2 = [array1
indexOfObject:@"-"];
        if (index < index2) {
            int a = [[array
objectAtIndex:index]intValue];
            int b = [[array
objectAtIndex:index+1]intValue];
            a = a + b;
            [array1 removeObjectAtIndex:index];
            [array removeObjectAtIndex:index];
            [array removeObjectAtIndex:index];
            [array insertObject:[NSStringstringWithFormat:@"%d",a]
atIndex:index];
        }
        else
        {
            int a = [[array
objectAtIndex:index2]intValue];
            int b = [[array
objectAtIndex:index2+1]intValue];
            a = a - b;
            [array1 removeObjectAtIndex:index2];
            [array removeObjectAtIndex:index2];
            [array removeObjectAtIndex:index2];
            [array insertObject:[NSStringstringWithFormat:@"%d",a]
atIndex:index2];
        }
    }
    return [array[0]intValue];
}

- (void)subCharToString
{
    if(_string.length >0)
    {
        [_stringdeleteCharactersInRange:NSMakeRange(0,_string.length)];
        _lable.text =_string;
    }
}
- (void)addCharToString:(UIButton *)button
{
    if(_flag ==
YES){
        if(button.tag !=10)
            [_stringreplaceCharactersInRange:NSMakeRange(0,_string.length)withString:@""];
        _flag = NO;
    }
        [_stringappendString:[button
titleForState:UIControlStateNormal]];
        _lable.text =_string;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application
and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}

- (void)applicationDidEnterBackground:(UIApplication *)application
{
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. 
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

- (void)applicationWillEnterForeground:(UIApplication *)application
{
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

- (void)applicationWillTerminate:(UIApplication *)application
{
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

@end