一些 iOS 代码片段

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//获取当前屏幕显示的viewcontroller
- (UIViewController *)getCurrentVC
{
    UIViewController *result = nil;
    
    UIWindow * window = [[UIApplication sharedApplication] keyWindow];
    if (window.windowLevel != UIWindowLevelNormal)
    {
        NSArray *windows = [[UIApplication sharedApplication] windows];
        for(UIWindow * tmpWin in windows)
        {
            if (tmpWin.windowLevel == UIWindowLevelNormal)
            {
                window = tmpWin;
                break;
            }
        }
    }
    
    UIView *frontView = [[window subviews] objectAtIndex:0];
    id nextResponder = [frontView nextResponder];
    
    if ([nextResponder isKindOfClass:[UIViewController class]])
        result = nextResponder;
    else
        result = window.rootViewController;
    
    return result;
}

然后在想使用的地方,直接就可以调用这个函数,然后加上了,比如说现在声明的那个view里面写了这个,当想加上去的时候可以直接这样

[[self getCurrentVC].view addSubview:self]

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IOS 遍历未知对象的属性和方法
/* 注意：要先导入ObjectC运行时头文件，以便调用runtime中的方法*/
#import <objc/runtime.h>

@implementation NSObject (PropertyListing)   

//1、/* 获取对象的所有属性，不包括属性值 */
- (NSArray *)getAllProperties
{
   u_int count;   
   objc_property_t *properties  =class_copyPropertyList([self class], &count);  
   NSMutableArray *propertiesArray = [NSMutableArray arrayWithCapacity:count];   
   for (int i = 0; i<count; i++)
    {
       const char* propertyName =property_getName(properties[i]);
       [propertiesArray addObject: [NSString stringWithUTF8String: propertyName]];   
    }   
   free(properties);   
   return propertiesArray;  
}  

//2、/* 获取对象的所有属性 以及属性值 */
- (NSDictionary *)properties_aps
{
   NSMutableDictionary *props = [NSMutableDictionary dictionary];   
   unsigned int outCount, i;   
   objc_property_t *properties = class_copyPropertyList([self class], &outCount);   
   for (i = 0; i<outCount; i++)
    {
       objc_property_t property = properties[i];
       const char* char_f =property_getName(property);
       NSString *propertyName = [NSString stringWithUTF8String:char_f];
       id propertyValue = [self valueForKey:(NSString *)propertyName];   
       if (propertyValue) [props setObject:propertyValue forKey:propertyName];   
    }   
   free(properties);   
   return props;   
}   

//3、/* 获取对象的所有方法 */
-(void)printMothList
{
   unsigned int mothCout_f =0;
   Method* mothList_f = class_copyMethodList([self class],&mothCout_f);
   for(int i=0;i<mothCout_f;i++)
    {
       Method temp_f = mothList_f[i];
       IMP imp_f = method_getImplementation(temp_f);
       SEL name_f = method_getName(temp_f);
       const char* name_s =sel_getName(method_getName(temp_f));
       int arguments = method_getNumberOfArguments(temp_f);
       const char* encoding =method_getTypeEncoding(temp_f);
       NSLog(@"方法名：%@,参数个数：%d,编码方式：%@",[NSString stringWithUTF8String:name_s],
                                  arguments,[NSString stringWithUTF8String:encoding]);
    }
   free(mothList_f);
}

@end 

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//获取已用存储和可用存储

// 获取占用内存 
-(void)usedSpaceAndfreeSpace 
{ 
    NSString* path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; 
    NSFileManager* fileManager = [[NSFileManager alloc ]init]; 
    NSDictionary *fileSysAttributes = [fileManager attributesOfFileSystemForPath:path error:nil]; 
    NSNumber *freeSpace = [fileSysAttributes objectForKey:NSFileSystemFreeSize]; 
    NSNumber *totalSpace = [fileSysAttributes objectForKey:NSFileSystemSize]; 
    NSString * str= [NSString stringWithFormat:@"已占用%0.1f G / 剩余%0.1f MB",([totalSpace longLongValue] - [freeSpace longLongValue])/1024.0/1024.0/1024.0,[freeSpace longLongValue]/1024.0/1024.0]; 
    NSLog(@"--------%@",str); 
}


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计算单个文件大小

+(float)fileSizeAtPath:(NSString *)path{
    NSFileManager *fileManager=[NSFileManager defaultManager];
    if([fileManager fileExistsAtPath:path]){
        long long size=[fileManager attributesOfItemAtPath:path error:nil].fileSize;
        return size/1024.0/1024.0;
    }
    return 0;
}
 

计算目录大小
+(float)folderSizeAtPath:(NSString *)path{
    NSFileManager *fileManager=[NSFileManager defaultManager];
    float folderSize;
    if ([fileManager fileExistsAtPath:path]) {
        NSArray *childerFiles=[fileManager subpathsAtPath:path];
        for (NSString *fileName in childerFiles) {
            NSString *absolutePath=[path stringByAppendingPathComponent:fileName];
            folderSize +=[FileService fileSizeAtPath:absolutePath];
        }
　　　　　//SDWebImage框架自身计算缓存的实现
        folderSize+=[[SDImageCache sharedImageCache] getSize]/1024.0/1024.0;
        return folderSize;
    }
    return 0;
}


清理缓存文件

同样也是利用NSFileManager API进行文件操作，SDWebImage框架自己实现了清理缓存操作，我们可以直接调用。

+(void)clearCache:(NSString *)path{
    NSFileManager *fileManager=[NSFileManager defaultManager];
    if ([fileManager fileExistsAtPath:path]) {
        NSArray *childerFiles=[fileManager subpathsAtPath:path];
        for (NSString *fileName in childerFiles) {
            //如有需要，加入条件，过滤掉不想删除的文件
            NSString *absolutePath=[path stringByAppendingPathComponent:fileName];
            [fileManager removeItemAtPath:absolutePath error:nil];
        }
    }
    [[SDImageCache sharedImageCache] cleanDisk];
}


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iOS开发 之 WebView点击图片看大图效果

http://www.w2bc.com/Article/44789

- (void)webViewDidFinishLoad:(UIWebView *)aWebView {
 
    //调整字号
    NSString *str = @"document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust= '95%'";
    [webView stringByEvaluatingJavaScriptFromString:str];
     
    //js方法遍历图片添加点击事件 返回图片个数
    static  NSString * const jsGetImages =
    @"function getImages(){\
    var objs = document.getElementsByTagName(\"img\");\
                                             for(var i=0;i<objs.length;i++){\
                                                 objs[i].onclick=function(){\
                                                     document.location=\"myweb:imageClick:\"+this.src;\
                                                 };\
                                             };\
                                             return objs.length;\
                                             };";
     
    [webView stringByEvaluatingJavaScriptFromString:jsGetImages];//注入js方法
     
    //注入自定义的js方法后别忘了调用 否则不会生效（不调用也一样生效了，，，不明白）
    NSString *resurlt = [webView stringByEvaluatingJavaScriptFromString:@"getImages()"];
    //调用js方法
//    NSLog(@"---调用js方法--%@  %s  jsMehtods_result = %@",self.class,__func__,resurlt);
}



- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
    //将url转换为string
    NSString *requestString = [[request URL] absoluteString];
//    NSLog(@"requestString is %@",requestString);
     
    //hasPrefix 判断创建的字符串内容是否以pic:字符开始
    if ([requestString hasPrefix:@"myweb:imageClick:"]) {
        NSString *imageUrl = [requestString substringFromIndex:@"myweb:imageClick:".length];
//        NSLog(@"image url------%@", imageUrl);
         
        if (bgView) {
            //设置不隐藏，还原放大缩小，显示图片
            bgView.hidden = NO;
            imgView.frame = CGRectMake(10, 10, SCREEN_WIDTH-40, 220);
            [imgView setImageWithURL:[NSURL URLWithString:imageUrl] placeholderImage:LOAD_IMAGE(@"house_moren")];
        }
        else
            [self showBigImage:imageUrl];//创建视图并显示图片
         
        return NO;
    }
    return YES;
}



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        NSString * titleText = [NSString stringWithFormat:@"搜索\"%@\"",self.categoryName];
        //重点字
        NSMutableDictionary *attributes = [NSMutableDictionary new];
        NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:titleText attributes:attributes];
        [attributedString addAttribute:NSForegroundColorAttributeName value:[UIColor colorWithRed:0.852 green:0.000 blue:0.016 alpha:1.000] range:[attributedString.string rangeOfString:self.categoryName]];
        self.naviTitleLabel.attributedText = attributedString;



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字体居左
btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;


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-(void) setFade
{
    _type=kCATransitionFade;
    
}

-(void) setCube
{
   _type=@"cube";
}

-(void) setFlip
{
   _type= @"oglFlip";
}


        CATransition *transtion = [CATransition animation];
        transtion.duration = 0.5;
        [transtion setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
        [transtion setType:_type];
        [transtion setSubtype:kCATransitionFromRight];
        
        [view.layer addAnimation:transtion forKey:@"transtionKey"];
        
        
        [(UIImageView*)view setImage:small];

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 //自动缩放字体
  
  self.priceTotalLabel.adjustsFontSizeToFitWidth = YES;
  self.priceTotalLabel.baselineAdjustment        = UIBaselineAdjustmentAlignCenters;      


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iOS7 custom leftBarButtonItem 偏移问题

- (void)createNavigationLeftBarButtonItemWithCustomView:(UIButton *)button
{
    UIBarButtonItem *buttonItem = [[UIBarButtonItem alloc] initWithCustomView:button];
    if ([[[[UIDevice currentDevice] systemVersion] substringToIndex:1] intValue]>=7) {
        UIBarButtonItem *negativeSpacer = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
        negativeSpacer.width = -10;
        self.navigationItem.leftBarButtonItems = @[negativeSpacer, buttonItem];
    }else{
        self.navigationItem.leftBarButtonItem = buttonItem;
    }
}


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- (id) setNoNull:(id)aValue{
    if (aValue == nil) {
        aValue = @"";//为null时，直接赋空
    } else if ((NSNull *)aValue == [NSNull null]) {
        aValue = @"";
        if ([aValue isEqual:nil]) {
            aValue = @"";
        }
    }
    return aValue;
}


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定义Block

@property (nonatomic, copy, nonnull) dispatch_block_t clickedBlock;

typedef void(^MBCClickedSearchBlock)(NSString * _Nullable searchWord);
@property (nonatomic, copy, nonnull) MBCClickedSearchBlock clickedSearchBlock;



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// 字体
#define HeitiLight(f) [UIFont fontWithName:@"STHeitiSC-Light" size:f]


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    // 设置回调（一旦进入刷新状态，就调用target的action，也就是调用self的loadMoreData方法）
    MJRefreshAutoNormalFooter *footer = [MJRefreshAutoNormalFooter footerWithRefreshingTarget:self refreshingAction:@selector(loadNewData)];
    // 设置文字
    [footer setTitle:@"Click or drag up to refresh" forState:MJRefreshStateIdle];
    [footer setTitle:@"Loading more ..." forState:MJRefreshStateRefreshing];
    [footer setTitle:@"No more data" forState:MJRefreshStateNoMoreData];
    
    // 设置字体
    footer.stateLabel.font = [UIFont systemFontOfSize:17];
    
    // 设置颜色
    footer.stateLabel.textColor = [UIColor blueColor];
    
    self.tableView.mj_footer = footer;

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NSDate如何获取一个月后的日期 
使用添加月份即可：

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

    NSDateComponents *comps = nil;

    comps = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:mydate];

    NSDateComponents *adcomps = [[NSDateComponents alloc] init];

    [adcomps setYear:0];

    [adcomps setMonth:-1];

    [adcomps setDay:0];

    NSDate *newdate = [calendar dateByAddingComponents:adcomps toDate:mydate options:0];


设置你需要增加或减少的年、月、日即可获得新的日期，上述的表示获取mydate日期前一个月的日期，如果该成+1，则是一个月以后的日期，以此类推都可以计算。


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Label内容段落间隔

- (void)handleLabel:(UILabel *)cLabel lineSpace:(float)lineSpace{
    cLabel.numberOfLines = 0;
    cLabel.lineBreakMode = NSLineBreakByTruncatingTail;
    cLabel.textAlignment = NSTextAlignmentLeft;
    
    NSMutableParagraphStyle * paragraph = [[NSMutableParagraphStyle alloc]init];
    paragraph.alignment = NSTextAlignmentLeft; //对齐
    paragraph.firstLineHeadIndent = 0.0;
    paragraph.paragraphSpacingBefore = 0.0;
    paragraph.lineSpacing = lineSpace;
    paragraph.paragraphSpacing = 8;
    paragraph.hyphenationFactor = 1.0;
    paragraph.headIndent = 0;
    paragraph.tailIndent = 0;
    
    NSDictionary *attributest = @{NSParagraphStyleAttributeName : paragraph};
    NSAttributedString *attributedText = [[NSAttributedString alloc]initWithString:cLabel.text attributes:attributest];
    cLabel.attributedText = attributedText;
}



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跳转到appstore评分
                
NSString *reviews = [NSString stringWithFormat:@"http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?id=%@&pageNumber=0&sortOrdering=2&type=Purple+Software&mt=8",K_MBC_AppStore_ID];



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程序内显示AppStore信息

@interface ViewController ()<SKStoreProductViewControllerDelegate>{
    SKStoreProductViewController *storeProductViewController;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    storeProductViewController = [[SKStoreProductViewController alloc] init];
    [storeProductViewController setDelegate:self];
}

#pragma mark Store Product View Controller Delegate Methods
- (void)productViewControllerDidFinish:(SKStoreProductViewController *)viewController {
    NSLog(@"操作结束");
    [self dismissViewControllerAnimated:YES completion:nil];
}


- (IBAction)openStoreAction:(UIButton *)sender {
    
    [storeProductViewController loadProductWithParameters:@{SKStoreProductParameterITunesItemIdentifier :@"1088202830"} completionBlock:^(BOOL result, NSError *error) {
        if (error) {
            NSLog(@"Error %@ with User Info %@.", error, [error userInfo]);
            
        } else {
            NSLog(@"正在获取信息");
            // Present Store Product View Controller
            [self presentViewController:storeProductViewController animated:YES completion:nil];
        }
    }];
}


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        // 调试函数耗时的利器
        CFAbsoluteTime start = CFAbsoluteTimeGetCurrent();
        // do something
        CFAbsoluteTime end = CFAbsoluteTimeGetCurrent();
        NSLog(@"time cost: %0.3f", end - start);


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//Attributed String控制文字
+ (NSMutableAttributedString *)generateAttributedStringFromString:(NSString *)string
withFontName:(NSString *)fontName
fontSize:(float)fontSize
textAlignment:(NSTextAlignment)alignment
lineBreakMode:(NSLineBreakMode)lineBreakMode
{
    NSMutableAttributedString *mutableAttributedString = [[NSMutableAttributedString alloc] initWithString:string];
    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
    style.lineSpacing = fontSize / 2;
    style.alignment = alignment;
    style.lineBreakMode = lineBreakMode;
    [mutableAttributedString addAttribute:(NSString*)kCTParagraphStyleAttributeName value:style range:NSMakeRange(0, [mutableAttributedString length])];
    [mutableAttributedString addAttribute:NSFontAttributeName value:[UIFont fontWithName:fontName size:fontSize] range:NSMakeRange(0, [mutableAttributedString length])];
    return mutableAttributedString;
}