你想要的iOS 小技巧总结

//分组列表头部空白处理
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 0.1)];
self.tableView.tableHeaderView = view;

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat sectionHeaderHeight = sectionHead.height;
    if (scrollView.contentOffset.y<=sectionHeaderHeight&&scrollView;.contentOffset.y>=0)
    {
        scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
    }
    else if(scrollView.contentOffset.y>=sectionHeaderHeight)
    {
        scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0);
    }
}

- (UIViewController *)viewController
{
  UIViewController *viewController = nil;  
  UIResponder *next = self.nextResponder;
  while (next)
  {
    if ([next isKindOfClass:[UIViewController class]])
    {
      viewController = (UIViewController *)next;      
      break;    
    }    
    next = next.nextResponder;  
  } 
    return viewController;
}

//方法一
NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];


//方法二
- (void)resetDefaults
{
    NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
    NSDictionary * dict = [defs dictionaryRepresentation];
    for (id key in dict)
    {
        [defs removeObjectForKey:key];
    }
    [defs synchronize];
}

#pragma mark - 打印系统所有已注册的字体名称
void enumerateFonts()
{
    for(NSString *familyName in [UIFont familyNames])
   {
        NSLog(@"%@",familyName);               
        NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName];       
        for(NSString *fontName in fontNames)
       {
            NSLog(@"\t|- %@",fontName);
       }
   }
}

- (UIColor*) getPixelColorAtLocation:(CGPoint)point inImage:(UIImage *)image
{

    UIColor* color = nil;
    CGImageRef inImage = image.CGImage;
    CGContextRef cgctx = [self createARGBBitmapContextFromImage:inImage];

    if (cgctx == NULL) {
        return nil; /* error */
    }
    size_t w = CGImageGetWidth(inImage);
    size_t h = CGImageGetHeight(inImage);
    CGRect rect = {{0,0},{w,h}};

    CGContextDrawImage(cgctx, rect, inImage);
    unsigned char* data = CGBitmapContextGetData (cgctx);
    if (data != NULL) {
        int offset = 4*((w*round(point.y))+round(point.x));
        int alpha =  data[offset];
        int red = data[offset+1];
        int green = data[offset+2];
        int blue = data[offset+3];
        color = [UIColor colorWithRed:(red/255.0f) green:(green/255.0f) blue:
                 (blue/255.0f) alpha:(alpha/255.0f)];
    }
    CGContextRelease(cgctx);
    if (data) {
        free(data);
    }
    return color;
}

第一种：
- (NSString *)reverseWordsInString:(NSString *)str
{    
    NSMutableString *newString = [[NSMutableString alloc] initWithCapacity:str.length];
    for (NSInteger i = str.length - 1; i >= 0 ; i --)
    {
        unichar ch = [str characterAtIndex:i];       
        [newString appendFormat:@"%c", ch];    
    }    
     return newString;
}

//第二种：
- (NSString*)reverseWordsInString:(NSString*)str
{    
     NSMutableString *reverString = [NSMutableString stringWithCapacity:str.length];    
     [str enumerateSubstringsInRange:NSMakeRange(0, str.length) options:NSStringEnumerationReverse | NSStringEnumerationByComposedCharacterSequences  usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) { 
          [reverString appendString:substring];                         
      }];    
     return reverString;
}

[UIApplication sharedApplication].idleTimerDisabled = YES;
或
[[UIApplication sharedApplication] setIdleTimerDisabled:YES];

UIViewController *vc = [[UIViewController alloc] init];
UINavigationController *na = [[UINavigationController alloc] initWithRootViewController:vc];

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
{
     na.modalPresentationStyle = UIModalPresentationOverCurrentContext;
}
else
{
     self.modalPresentationStyle=UIModalPresentationCurrentContext;
}

[self presentViewController:na animated:YES completion:nil];

editSCheme  里面有个选项叫叫做enable zoombie Objects  取消选中

//显示
defaults write com.apple.finder AppleShowAllFiles -bool true
killall Finder

//隐藏
defaults write com.apple.finder AppleShowAllFiles -bool false
killall Finder

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"]];

+ (NSString *)transform:(NSString *)chinese
{    
    //将NSString装换成NSMutableString 
    NSMutableString *pinyin = [chinese mutableCopy];    
    //将汉字转换为拼音(带音标)    
    CFStringTransform((__bridge CFMutableStringRef)pinyin, NULL, kCFStringTransformMandarinLatin, NO);    
    NSLog(@"%@", pinyin);    
    //去掉拼音的音标    
    CFStringTransform((__bridge CFMutableStringRef)pinyin, NULL, kCFStringTransformStripCombiningMarks, NO);    
    NSLog(@"%@", pinyin);    
    //返回最近结果    
    return pinyin;
 }

- (void)setStatusBarBackgroundColor:(UIColor *)color
{
    UIView *statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"];

    if ([statusBar respondsToSelector:@selector(setBackgroundColor:)])
    {
        statusBar.backgroundColor = color;    
    }
}

NSArray *viewcontrollers=self.navigationController.viewControllers;

if (viewcontrollers.count > 1)
{
    if ([viewcontrollers objectAtIndex:viewcontrollers.count - 1] == self)
    {
        //push方式
       [self.navigationController popViewControllerAnimated:YES];
    }
}
else
{
    //present方式
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (NSString *)getLaunchImageName
{
    CGSize viewSize = self.window.bounds.size;
    // 竖屏    
    NSString *viewOrientation = @"Portrait";  
    NSString *launchImageName = nil;    
    NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
    for (NSDictionary* dict in imagesDict)
    {
        CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
        if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
        {
            launchImageName = dict[@"UILaunchImageName"];        
        }    
    }    
    return launchImageName;
}

UIWindow * keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView * firstResponder = [keyWindow performSelector:@selector(firstResponder)];

if ([self.selectedController conformsToProtocol:@protocol(RefreshPtotocol)])
{
     [self.selectedController performSelector:@selector(onTriggerRefresh)];
}

BOOL isView = [textView isDescendantOfView:self.view];

NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];
CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];
CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];
NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);

[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];

G: 公元时代，例如AD公元
yy: 年的后2位
yyyy: 完整年
MM: 月，显示为1-12
MMM: 月，显示为英文月份简写,如 Jan
MMMM: 月，显示为英文月份全称，如 Janualy
dd: 日，2位数表示，如02
d: 日，1-2位显示，如 2
EEE: 简写星期几，如Sun
EEEE: 全写星期几，如Sunday
aa: 上下午，AM/PM
H: 时，24小时制，0-23
K：时，12小时制，0-11
m: 分，1-2位
mm: 分，2位
s: 秒，1-2位
ss: 秒，2位
S: 毫秒

+ (NSArray *) allSubclasses
{
    Class myClass = [self class];
    NSMutableArray *mySubclasses = [NSMutableArray array];
    unsigned int numOfClasses;
    Class *classes = objc_copyClassList(&numOfClasses;);
    for (unsigned int ci = 0; ci < numOfClasses; ci++)
    {
        Class superClass = classes[ci];
        do{
            superClass = class_getSuperclass(superClass);
        } while (superClass && superClass != myClass);

        if (superClass)
        {
            [mySubclasses addObject: classes[ci]];
        }
    }
    free(classes);
    return mySubclasses;
}

NSDictionary *proxySettings = (__bridge NSDictionary *)(CFNetworkCopySystemProxySettings());
NSArray *proxies = (__bridge NSArray *)(CFNetworkCopyProxiesForURL((__bridge CFURLRef _Nonnull)([NSURL URLWithString:@"http://www.baidu.com"]), (__bridge CFDictionaryRef _Nonnull)(proxySettings)));
NSLog(@"\n%@",proxies);

NSDictionary *settings = proxies[0];
NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyHostNameKey]);
NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyPortNumberKey]);
NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyTypeKey]);

if ([[settings objectForKey:(NSString *)kCFProxyTypeKey] isEqualToString:@"kCFProxyTypeNone"])
{
     NSLog(@"没代理");
}
else
{
     NSLog(@"设置了代理");
}

+(NSString *)translation:(NSString *)arebic
{  
    NSString *str = arebic;
    NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"];
    NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];
    NSArray *digits = @[@"个",@"十",@"百",@"千",@"万",@"十",@"百",@"千",@"亿",@"十",@"百",@"千",@"兆"];
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:chinese_numerals forKeys:arabic_numerals];

    NSMutableArray *sums = [NSMutableArray array];
    for (int i = 0; i < str.length; i ++) {
        NSString *substr = [str substringWithRange:NSMakeRange(i, 1)];
        NSString *a = [dictionary objectForKey:substr];
        NSString *b = digits[str.length -i-1];
        NSString *sum = [a stringByAppendingString:b];
        if ([a isEqualToString:chinese_numerals[9]])
        {
            if([b isEqualToString:digits[4]] || [b isEqualToString:digits[8]])
            {
                sum = b;
                if ([[sums lastObject] isEqualToString:chinese_numerals[9]])
                {
                    [sums removeLastObject];
                }
            }else
            {
                sum = chinese_numerals[9];
            }

            if ([[sums lastObject] isEqualToString:sum])
            {
                continue;
            }
        }

        [sums addObject:sum];
    }

    NSString *sumStr = [sums componentsJoinedByString:@""];
    NSString *chinese = [sumStr substringToIndex:sumStr.length-1];
    NSLog(@"%@",str);
    NSLog(@"%@",chinese);
    return chinese;
}

// Create NSData object
NSData *nsdata = [@"iOS Developer Tips encoded in Base64"
  dataUsingEncoding:NSUTF8StringEncoding];

// Get NSString from NSData object in Base64
NSString *base64Encoded = [nsdata base64EncodedStringWithOptions:0];

// Print the Base64 encoded string
NSLog(@"Encoded: %@", base64Encoded);

// Let‘s go the other way...

// NSData from the Base64 encoded str
NSData *nsdataFromBase64String = [[NSData alloc]
  initWithBase64EncodedString:base64Encoded options:0];

// Decoded NSString from the NSData
NSString *base64Decoded = [[NSString alloc]
  initWithData:nsdataFromBase64String encoding:NSUTF8StringEncoding];
NSLog(@"Decoded: %@", base64Decoded);

//方法一
[UIView performWithoutAnimation:^{
    [collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]];
}];

//方法二
[UIView animateWithDuration:0 animations:^{
    [collectionView performBatchUpdates:^{
        [collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]];
    } completion:nil];
}];

//方法三
[UIView setAnimationsEnabled:NO];
[self.trackPanel performBatchUpdates:^{
    [collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]];
} completion:^(BOOL finished) {
    [UIView setAnimationsEnabled:YES];
}];

打开终端输入三条命令:
touch ~/.lldbinit
echo display @import UIKit >> ~/.lldbinit
echo target stop-hook add -o \"target stop-hook disable\" >> ~/.lldbinit

pod install --verbose --no-repo-update 
pod update --verbose --no-repo-update
如果不加后面的参数，默认会升级CocoaPods的spec仓库，加一个参数可以省略这一步，然后速度就会提升不少

UIImage *image = [UIImage imageNamed:@"aa"];
NSUInteger size  = CGImageGetHeight(image.CGImage) * CGImageGetBytesPerRow(image.CGImage);

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);
dispatch_source_set_timer(timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒执行
dispatch_source_set_event_handler(timer, ^{
    //@"倒计时结束，关闭"
    dispatch_source_cancel(timer); 
    dispatch_async(dispatch_get_main_queue(), ^{

    });
});
dispatch_resume(timer);

- (UIImage *)imageWithTitle:(NSString *)title fontSize:(CGFloat)fontSize
{
    //画布大小
    CGSize size=CGSizeMake(self.size.width,self.size.height);
    //创建一个基于位图的上下文
    UIGraphicsBeginImageContextWithOptions(size,NO,0.0);//opaque:NO  scale:0.0

    [self drawAtPoint:CGPointMake(0.0,0.0)];

    //文字居中显示在画布上
    NSMutableParagraphStyle* paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
    paragraphStyle.lineBreakMode = NSLineBreakByCharWrapping;
    paragraphStyle.alignment=NSTextAlignmentCenter;//文字居中

    //计算文字所占的size,文字居中显示在画布上
    CGSize sizeText=[title boundingRectWithSize:self.size options:NSStringDrawingUsesLineFragmentOrigin
                                     attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:fontSize]}context:nil].size;
    CGFloat width = self.size.width;
    CGFloat height = self.size.height;

    CGRect rect = CGRectMake((width-sizeText.width)/2, (height-sizeText.height)/2, sizeText.width, sizeText.height);
    //绘制文字
    [title drawInRect:rect withAttributes:@{ NSFontAttributeName:[UIFont systemFontOfSize:fontSize],NSForegroundColorAttributeName:[ UIColor whiteColor],NSParagraphStyleAttributeName:paragraphStyle}];

    //返回绘制的新图形
    UIImage *newImage= UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

- (NSMutableArray *)allSubViewsForView:(UIView *)view
{
    NSMutableArray *array = [NSMutableArray arrayWithCapacity:0];
    for (UIView *subView in view.subviews)
    {
        [array addObject:subView];
        if (subView.subviews.count > 0)
        {
            [array addObjectsFromArray:[self allSubViewsForView:subView]];
        }
    }
    return array;
}

//文件大小
- (long long)fileSizeAtPath:(NSString *)path
{
    NSFileManager *fileManager = [NSFileManager defaultManager];

    if ([fileManager fileExistsAtPath:path])
    {
        long long size = [fileManager attributesOfItemAtPath:path error:nil].fileSize;
        return size;
    }

    return 0;
}

//文件夹大小
- (long long)folderSizeAtPath:(NSString *)path
{
    NSFileManager *fileManager = [NSFileManager defaultManager];

    long long folderSize = 0;

    if ([fileManager fileExistsAtPath:path])
    {
        NSArray *childerFiles = [fileManager subpathsAtPath:path];
        for (NSString *fileName in childerFiles)
        {
            NSString *fileAbsolutePath = [path stringByAppendingPathComponent:fileName];
            if ([fileManager fileExistsAtPath:fileAbsolutePath])
            {
                long long size = [fileManager attributesOfItemAtPath:fileAbsolutePath error:nil].fileSize;
                folderSize += size;
            }
        }
    }

    return folderSize;
}

CGRect rect = view.bounds;
CGSize radio = CGSizeMake(30, 30);//圆角尺寸
UIRectCorner corner = UIRectCornerTopLeft|UIRectCornerTopRight;//这只圆角位置
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect byRoundingCorners:corner cornerRadii:radio];
CAShapeLayer *masklayer = [[CAShapeLayer alloc]init];//创建shapelayer
masklayer.frame = view.bounds;
masklayer.path = path.CGPath;//设置路径
view.layer.mask = masklayer;

floor(x),有时候也写做Floor(x)，其功能是“下取整”，即取不大于x的最大整数 例如：
x=3.14，floor(x)=3
y=9.99999，floor(y)=9

与floor函数对应的是ceil函数，即上取整函数。

ceil函数的作用是求不小于给定实数的最小整数。
ceil(2)=ceil(1.2)=cei(1.5)=2.00

floor函数与ceil函数的返回值均为double型

//方法一：
- (int)convertToInt:(NSString*)strtemp
{
    int strlength = 0;
    char* p = (char*)[strtemp cStringUsingEncoding:NSUnicodeStringEncoding];
    for (int i=0 ; i<[strtemp lengthOfBytesUsingEncoding:NSUnicodeStringEncoding] ;i++)
    {
        if (*p)
        {
            p++;
            strlength++;
        }
        else
        {
            p++;
        }

    }
    return strlength;
}

//方法二：
-(NSUInteger) unicodeLengthOfString: (NSString *) text
{
    NSUInteger asciiLength = 0;
    for (NSUInteger i = 0; i < text.length; i++)
    {
        unichar uc = [text characterAtIndex: i];
        asciiLength += isascii(uc) ? 1 : 2;
    }
    return asciiLength;
}

UIImage *image = [UIImage imageNamed:@"image"];
self.MYView.layer.contents = (__bridge id _Nullable)(image.CGImage);
self.MYView.layer.contentsRect = CGRectMake(0, 0, 0.5, 0.5);

[scrollView.panGestureRecognizerrequireGestureRecognizerToFail:self.navigationController.interactivePopGestureRecognizer];

[[UIBarButtonItemappearance]setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)forBarMetrics:UIBarMetricsDefault];

+ (BOOL)checkIsChinese:(NSString *)string
{
    for (int i=0; i<string.length; i++)
    {
        unichar ch = [string characterAtIndex:i];
        if (0x4E00 <= ch  && ch <= 0x9FA5)
        {
            return YES;
        }
    }
    return NO;
}

dispatch_group_t dispatchGroup = dispatch_group_create();
    dispatch_group_enter(dispatchGroup);
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        NSLog(@"第一个请求完成");
        dispatch_group_leave(dispatchGroup);
    });

    dispatch_group_enter(dispatchGroup);

    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(10 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        NSLog(@"第二个请求完成");
        dispatch_group_leave(dispatchGroup);
    });

    dispatch_group_notify(dispatchGroup, dispatch_get_main_queue(), ^(){
        NSLog(@"请求完成");
    });

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    // 四位加一个空格
    if ([string isEqualToString:@""])
    {
        // 删除字符
        if ((textField.text.length - 2) % 5 == 0)
        {
            textField.text = [textField.text substringToIndex:textField.text.length - 1];
        }
        return YES;
    }
    else
    {
        if (textField.text.length % 5 == 0)
        {
            textField.text = [NSString stringWithFormat:@"%@ ", textField.text];
        }
    }
    return YES;
}

//获取私有属性 比如设置UIDatePicker的字体颜色
- (void)setTextColor
{
    //获取所有的属性，去查看有没有对应的属性
    unsigned int count = 0;
    objc_property_t *propertys = class_copyPropertyList([UIDatePicker class], &count);
    for(int i = 0;i < count;i ++)
    {
        //获得每一个属性
        objc_property_t property = propertys[i];
        //获得属性对应的nsstring
        NSString *propertyName = [NSString stringWithCString:property_getName(property) encoding:NSUTF8StringEncoding];
        //输出打印看对应的属性
        NSLog(@"propertyname = %@",propertyName);
        if ([propertyName isEqualToString:@"textColor"])
        {
            [datePicker setValue:[UIColor whiteColor] forKey:propertyName];
        }
    }
}
//获得成员变量 比如修改UIAlertAction的按钮字体颜色
    unsigned int count = 0;
    Ivar *ivars = class_copyIvarList([UIAlertAction class], &count);
    for(int i =0;i < count;i ++)
    {
        Ivar ivar = ivars[i];
        NSString *ivarName = [NSString stringWithCString:ivar_getName(ivar) encoding:NSUTF8StringEncoding];
        NSLog(@"uialertion.ivarName = %@",ivarName);
        if ([ivarName isEqualToString:@"_titleTextColor"])
        {
            [alertOk setValue:[UIColor blueColor] forKey:@"titleTextColor"];
            [alertCancel setValue:[UIColor purpleColor] forKey:@"titleTextColor"];
        }
    }

Class c =NSClassFromString(@"LSApplicationWorkspace");
id s = [(id)c performSelector:NSSelectorFromString(@"defaultWorkspace")];
NSArray *array = [s performSelector:NSSelectorFromString(@"allInstalledApplications")];
for (id item in array)
{
    NSLog(@"%@",[item performSelector:NSSelectorFromString(@"applicationIdentifier")]);
    //NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleIdentifier")]);
    NSLog(@"%@",[item performSelector:NSSelectorFromString(@"bundleVersion")]);
    NSLog(@"%@",[item performSelector:NSSelectorFromString(@"shortVersionString")]);
}

- (BOOL)isSameDateWithDate:(NSDate *)date
{
    //日期间隔大于七天之间返回NO
    if (fabs([self timeIntervalSinceDate:date]) >= 7 * 24 *3600)
    {
        return NO;
    }

    NSCalendar *calender = [NSCalendar currentCalendar];
    calender.firstWeekday = 2;//设置每周第一天从周一开始
    //计算两个日期分别为这年第几周
    NSUInteger countSelf = [calender ordinalityOfUnit:NSCalendarUnitWeekday inUnit:NSCalendarUnitYear forDate:self];
    NSUInteger countDate = [calender ordinalityOfUnit:NSCalendarUnitWeekday inUnit:NSCalendarUnitYear forDate:date];

    //相等就在同一周，不相等就不在同一周
    return countSelf == countDate;
}

//iOS8之后
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
//如果App没有添加权限，显示的是设定界面。如果App有添加权限（例如通知），显示的是App的设定界面。
//iOS8之前
//先添加一个url type如下图，在代码中调用如下代码,即可跳转到设置页面的对应项
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=WIFI"]];

可选值如下：
About — prefs:root=General&path=About
Accessibility — prefs:root=General&path=ACCESSIBILITY
Airplane Mode On — prefs:root=AIRPLANE_MODE
Auto-Lock — prefs:root=General&path=AUTOLOCK
Brightness — prefs:root=Brightness
Bluetooth — prefs:root=General&path=Bluetooth
Date & Time — prefs:root=General&path=DATE_AND_TIME
FaceTime — prefs:root=FACETIME
General — prefs:root=General
Keyboard — prefs:root=General&path=Keyboard
iCloud — prefs:root=CASTLE
iCloud Storage & Backup — prefs:root=CASTLE&path=STORAGE_AND_BACKUP
International — prefs:root=General&path=INTERNATIONAL
Location Services — prefs:root=LOCATION_SERVICES
Music — prefs:root=MUSIC
Music Equalizer — prefs:root=MUSIC&path=EQ
Music Volume Limit — prefs:root=MUSIC&path=VolumeLimit
Network — prefs:root=General&path=Network
Nike + iPod — prefs:root=NIKE_PLUS_IPOD
Notes — prefs:root=NOTES
Notification — prefs:root=NOTIFICATI*****_ID
Phone — prefs:root=Phone
Photos — prefs:root=Photos
Profile — prefs:root=General&path=ManagedConfigurationList
Reset — prefs:root=General&path=Reset
Safari — prefs:root=Safari
Siri — prefs:root=General&path=Assistant
Sounds — prefs:root=Sounds
Software Update — prefs:root=General&path=SOFTWARE_UPDATE_LINK
Store — prefs:root=STORE
Twitter — prefs:root=TWITTER
Usage — prefs:root=General&path=USAGE
VPN — prefs:root=General&path=Network/VPN
Wallpaper — prefs:root=Wallpaper
Wi-Fi — prefs:root=WIFI