iOS开发常用代码块（2）

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;

//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;
}

[scrollView.panGestureRecognizer requireGestureRecognizerToFail:self.navigationController.interactivePopGestureRecognizer];

[[UIBarButtonItem appearance]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;
}

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(@"bundleVersion")]);
    NSLog(@"%@",[item performSelector:NSSelectorFromString(@"shortVersionString")]);
}

//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，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

-(void)pauseLayer:(CALayer *)layer
{
    CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
    layer.speed = 0.0;
    layer.timeOffset = pausedTime;
}

-(void)resumeLayer:(CALayer *)layer
{
    CFTimeInterval pausedTime = [layer timeOffset];
    layer.speed = 1.0;
    layer.timeOffset = 0.0;
    layer.beginTime = 0.0;
    CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
    layer.beginTime = timeSincePause;
}

//通过NSNumberFormatter，同样可以设置NSNumber输出的格式。例如如下代码：
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
formatter.numberStyle = NSNumberFormatterDecimalStyle;
NSString *string = [formatter stringFromNumber:[NSNumber numberWithInt:123456789]];
NSLog(@"Formatted number string:%@",string);
//输出结果为：[1223:403] Formatted number string:123,456,789

//其中NSNumberFormatter类有个属性numberStyle，它是一个枚举型，设置不同的值可以输出不同的数字格式。该枚举包括：
typedef NS_ENUM(NSUInteger, NSNumberFormatterStyle) {
    NSNumberFormatterNoStyle = kCFNumberFormatterNoStyle,
    NSNumberFormatterDecimalStyle = kCFNumberFormatterDecimalStyle,
    NSNumberFormatterCurrencyStyle = kCFNumberFormatterCurrencyStyle,
    NSNumberFormatterPercentStyle = kCFNumberFormatterPercentStyle,
    NSNumberFormatterScientificStyle = kCFNumberFormatterScientificStyle,
    NSNumberFormatterSpellOutStyle = kCFNumberFormatterSpellOutStyle
};
//各个枚举对应输出数字格式的效果如下：其中第三项和最后一项的输出会根据系统设置的语言区域的不同而不同。
[1243:403] Formatted number string:123456789
[1243:403] Formatted number string:123,456,789
[1243:403] Formatted number string:￥123,456,789.00
[1243:403] Formatted number string:-539,222,988%
[1243:403] Formatted number string:1.23456789E8
[1243:403] Formatted number string:一亿二千三百四十五万六千七百八十九

//UIWebView
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
    //这里是js，主要目的实现对url的获取
    static  NSString * const jsGetImages =
    @"function getImages(){    var objs = document.getElementsByTagName(\"img\");    var imgScr = ‘‘;    for(var i=0;i<objs.length;i++){    imgScr = imgScr + objs[i].src + ‘+‘;    };    return imgScr;    };";

    [webView stringByEvaluatingJavaScriptFromString:jsGetImages];//注入js方法
    NSString *urlResult = [webView stringByEvaluatingJavaScriptFromString:@"getImages()"];
    NSArray *urlArray = [NSMutableArray arrayWithArray:[urlResult componentsSeparatedByString:@"+"]];
    //urlResurlt 就是获取到得所有图片的url的拼接；mUrlArray就是所有Url的数组
}

//WKWebView
- (void)webView:(WKWebView *)webView didFinishNavigation:(null_unspecified WKNavigation *)navigation
{
    static  NSString * const jsGetImages =
    @"function getImages(){    var objs = document.getElementsByTagName(\"img\");    var imgScr = ‘‘;    for(var i=0;i<objs.length;i++){    imgScr = imgScr + objs[i].src + ‘+‘;    };    return imgScr;    };";

    [webView evaluateJavaScript:jsGetImages completionHandler:nil];
    [webView evaluateJavaScript:@"getImages()" completionHandler:^(id _Nullable result, NSError * _Nullable error) {
        NSLog(@"%@",result);
    }];
}

CGFloat height = [[self.webView stringByEvaluatingJavaScriptFromString:@"document.body.offsetHeight"] floatValue];

//第一种方法
//导航栏纯透明
[self.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
//去掉导航栏底部的黑线
self.navigationBar.shadowImage = [UIImage new];

//第二种方法
[[self.navigationBar subviews] objectAtIndex:0].alpha = 0;

[self.tabBar setBackgroundImage:[UIImage new]];
self.tabBar.shadowImage = [UIImage new];

//第一种
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat offsetToShow = 200.0;//滑动多少就完全显示
    CGFloat alpha = 1 - (offsetToShow - scrollView.contentOffset.y) / offsetToShow;
    [[self.navigationController.navigationBar subviews] objectAtIndex:0].alpha = alpha;
}

//第二种
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat offsetToShow = 200.0;
    CGFloat alpha = 1 - (offsetToShow - scrollView.contentOffset.y) / offsetToShow;

    [self.navigationController.navigationBar setShadowImage:[UIImage new]];
    [self.navigationController.navigationBar setBackgroundImage:[self imageWithColor:[[UIColor orangeColor]colorWithAlphaComponent:alpha]] forBarMetrics:UIBarMetricsDefault];
}

//生成一张纯色的图片
- (UIImage *)imageWithColor:(UIColor *)color
{
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return theImage;
}