Common Code blocks for iOS development (2): ios development code

Common Code blocks for iOS development (2): ios development code
GCD Timer

Required queue = hour (hour, 0); dispatch_source_t timer = dispatch_source_create (hour, 0, 0, queue); hour (timer, dispatch_walltime (NULL, 0), 1.0 * NSEC_PER_SEC, 0); // execute the timer (timer, ^ {// The countdown ends. Disable dispatch_source_cancel (timer); dispatch_async (dispatch_get_main_queue (), ^ {});}); dispatch_resume (timer );

 

Draw text on the Image

-(UIImage *) imageWithTitle :( NSString *) title fontSize :( CGFloat) fontSize {// canvas size CGSize size = CGSizeMake (self. size. width, self. size. height); // create a bitmap-based context uigraphicsbeginimagecontextwittions (size, NO, 0.0); // opaque: NO scale: 0.0 [self drawAtPoint: CGPointMake (0.0, 0.0)]; // The text is displayed in the center of the canvas. NSMutableParagraphStyle * paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy]; paragraphStyle. lineBreakMode = NSLineBreakByCharWrapping;
ParagraphStyle. alignment = NSTextAlignmentCenter; // center the text. // calculate the size occupied by the text. The text is displayed in the center of the canvas 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); // draw the text [title drawInRect: rect withAttributes: @ {NSFontAttributeName: [UIFont systemFontOfSize: fontSize], identifier: [UIColor whiteColor], identifier: paragraphStyle}]; // return the newly drawn image UIImage * newImage = UIGraphicsGetImageFromCurrentImageContext (); UIGraphicsEndImageContext (); return newImage ;}

 

Search for all subviews of a view

- (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;}

 

Calculate the file size

// File size-(long) fileSizeAtPath :( NSString *) path {NSFileManager * fileManager = [NSFileManager defaultManager]; if ([fileManager fileExistsAtPath: path]) {long size = [fileManager attributesOfItemAtPath: path error: nil]. fileSize; return size;} return 0;} // folder size-(long) folderSizeAtPath :( NSString *) path {NSFileManager * fileManager = [NSFileManager defaultManager]; long folderSize = 0; if ([fileManager fileExistsAtPath: path]) {NSArray * childerFiles = [fileManager subpathsAtPath: path]; for (NSString * fileName in childerFiles) {NSString * fileAbsolutePath = [path paths: fileName]; if ([fileManager fileExistsAtPath: fileAbsolutePath]) {long size = [fileManager attributesOfItemAtPath: fileAbsolutePath error: nil]. fileSize; folderSize + = size ;}} return folderSize ;}

 

Set partial rounded corner of UIView

CGRect rect = view. bounds; CGSize radio = CGSizeMake (30, 30); // corner size UIRectCorner corner = UIRectCornerTopLeft | border; // UIBezierPath * path = [UIBezierPath direction: rect limit: corner cornerRadii: radio]; CAShapeLayer * masklayer = [[CAShapeLayer alloc] init]; // create shapelayermasklayer. frame = view. bounds; masklayer. path = path. CGPath; // set the path view. layer. mask = masklayer;

 

Calculates the length of a string. One Chinese character is counted as two characters.

// Method 1:-(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 ;}// Method 2:-(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 ;}

 

Prevents the scrolling view gesture from overwriting the slide gesture

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

 

Remove the title returned from the navigation bar

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

 

Whether the string contains Chinese Characters

+ (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;}

 

Use of dispatch_group

Required dispatchGroup = dispatch_group_create (); dispatch_group_enter (dispatchGroup); dispatch_after (dispatch_time (interval, (int64_t) (1 * NSEC_PER_SEC), interval (), ^ {NSLog (@ "the first request is completed"); then (dispatchGroup) ;}); dispatch_group_enter (dispatchGroup); dispatch_after (dispatch_time (DISPATCH_TIME_NOW, (int64_t) (10 * NSEC_PER_SEC), complete (), ^ {NSLog (@ "second request completed"); dispatch_group_leave (dispatchGroup) ;}); dispatch_group_policy (dispatchGroup, assign (), ^ () {NSLog (@ "request completed ");});

 

UITextField adds a space every four digits to implement proxy

-(BOOL) textField :( UITextField *) textField shouldChangeCharactersInRange :( nsange) range replacementString :( NSString *) string {// four digits add a space if ([string isw.tostring: @ ""]) {// Delete the character 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 ;}

 

Get apps installed on mobile phones

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")]);}

 

Open the system settings page in the application.

// [[UIApplication sharedApplication] openURL: [NSURL URLWithString: UIApplicationOpenSettingsURLString] After iOS8; // If the App does not have the permission, the setting interface is displayed. If the App has the Add permission (for example, notification), the setting page of the App is displayed. // Before iOS8 // Add a url type and call the following code in the code to jump to the corresponding item [[UIApplication sharedApplication] openURL: [NSURL URLWithString: @ "prefs: root = WIFI"]; optional values: About-prefs: root = General & path = AboutAccessibility-prefs: root = General & path = ACCESSIBILITYAirplane Mode On-prefs: root = AIRPLANE_MODEAuto-Lock-prefs: root = General & path = AUTOLOCKBrightness-prefs: root = BrightnessBluetooth-prefs: root = General & path = effecthdate & Time-prefs: root = General & path = DATE_AND_TIMEFaceTime-prefs: root = FACETIMEGeneral-prefs: root = GeneralKeyboard-prefs: root = General & path = KeyboardiCloud-prefs: root = CASTLEiCloud Storage & Backup-prefs: root = CASTLE & path = STORAGE_AND_BACKUPInternational-prefs: root = General & path = INTERNATIONALLocation Services-prefs: root = LOCATION_SERVICESMusic-prefs: root = MUSICMusic Equalizer-prefs: root = MUSIC & path = EQMusic Volume Limit-prefs: root = MUSIC & path = VolumeLimitNetwork-prefs: root = General & path = NetworkNike + iPod-prefs: root = NIKE_PLUS_IPODNotes-prefs: root = NOTESNotification-prefs: root = NOTIFICATI ***** _ IDPhone-prefs: root = PhonePhotos-prefs: root = PhotosProfile-prefs: root = General & path = ManagedConfigurationListReset-prefs: root = General & path = ResetSafari-prefs: root = policissiri-prefs: root = General & path = AssistantSounds-prefs: root = SoundsSoftware Update-prefs: root = General & path = SOFTWARE_UPDATE_LINKStore-prefs: root = STORETwitter-prefs: root = TWITTERUsage-prefs: root = General & path = USAGEVPN-prefs: root = General & path = Network/VPNWallpaper-prefs: root = WallpaperWi-Fi-prefs: root = WIFI

 

Pause the animation and start again.

-(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;}

 

Number formatting in iOS

// You can also set the format of NSNumber output through NSNumberFormatter. For example, the following code: NSNumberFormatter * formatter = [[NSNumberFormatter alloc] init]; formatter. numberStyle = NSNumberFormatterDecimalStyle; NSString * string = [formatter stringFromNumber: [NSNumber numberWithInt: 123456789]; NSLog (@ "Formatted number string: % @", string ); // The output result is: [1223:403] Formatted number string: 123,456,789 // The NSNumberFormatter class has a property numberStyle, which is an enumeration type, you can set different values to output different numeric formats. This enumeration includes: typedef NS_ENUM (NSUInteger, NSNumberFormatterStyle) {NSNumberFormatterNoStyle = kCFNumberFormatterNoStyle, Signature = signature, Signature = signature, NSNumberFormatterPercentStyle = signature, Signature = delimiter, NSNumberFormatterSpellO UtStyle = kCFNumberFormatterSpellOutStyle}; // The output format of each enumeration is as follows: the output of the third and last entries varies depending on the language regions set by the system. [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: 0.1 billion 23,456,789

 

How to obtain all the image addresses of the WebView

// UIWebView-(void) webViewDidFinishLoad :( UIWebView *) webView {// This is js. It is mainly used to obtain 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]; // inject the js method NSString * urlResult = [webView progress: @ "getImages ()"]; NSArray * urlArray = [NSMutableArray arrayWithArray: [urlResult componentsSeparatedByString: @ "+"]; // urlResurlt is the splicing of the URLs of all images obtained; mUrlArray is the array of all URLs} // 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) ;}];}

 

Height of the obtained WebView

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

 

The navigation bar becomes transparent.

// Method 1 // The navigation bar is transparent [self. navigationBar setBackgroundImage: [UIImage new] forBarMetrics: UIBarMetricsDefault]; // remove the black line self at the bottom of the navigation bar. navigationBar. shadowImage = [UIImage new]; // method 2 [self. navigationBar subviews] objectAtIndex: 0]. alpha = 0;

 

TabBar becomes transparent

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

 

NavigationBar Gradient Based on sliding distance

// First-(void) scrollViewDidScroll :( UIScrollView *) scrollView {CGFloat offsetToShow = 200.0; // when the number of slides is displayed, CGFloat alpha = 1-(offsetToShow-scrollView. contentOffset. y)/offsetToShow; [[self. navigationController. navigationBar subviews] objectAtIndex: 0]. alpha = alpha;} // type 2-(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 orientation: [self imageWithColor: [[UIColor orangeColor] colorWithAlphaComponent: alpha] forBarMetrics: UIBarMetricsDefault];} // generates a solid color image (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 = Response (); Response (); return theImage ;}