Common code blocks for iOS development (2)

GCD Timer

dispatch_queue_t queue = Dispatch_get_global_queue (dispatch_queue_priority_default, 0);d ispatch_source_t timer = Dispatch_source_create (Dispatch_source_type_timer, 0, 0,queue);d Ispatch_source_set_timer (timer,dispatch_walltime (NULL, 0), 1.0*nsec_per_sec, 0); Execute Dispatch_source_set_event_handler per second (timer, ^{    //Countdown end, close    dispatch_source_cancel (timer);     Dispatch_async (Dispatch_get_main_queue (), ^{    });}); Dispatch_resume (timer);

Draw text on a picture

-(UIImage *) Imagewithtitle: (NSString *) title fontSize: (cgfloat) fontsize{//Canvas size cgsize size=cgsizemake (self.size.wi    Dth,self.size.height); Create a bitmap-based context uigraphicsbeginimagecontextwithoptions (size,no,0.0);//opaque:no scale:0.0 [Self drawatpoint:cgpoint    Make (0.0,0.0)];    Text centered on the canvas nsmutableparagraphstyle* paragraphstyle = [[Nsparagraphstyle Defaultparagraphstyle] mutableCopy]; Paragraphstyle.linebreakmode = nslinebreakbycharwrapping;
paragraphstyle.alignment=nstextalignmentcenter;//Text Center//Calculate the size of the text, text centered on the canvas cgsize sizetext=[title BoundingRectWithSize:self.size Options:nsstringdrawinguseslinefragmentorigin Attribute    S:@{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 text [title Drawinrect:rect withattributes:@{Nsfontattributename:[uifont Systemfontofsize:fontsize],    nsforegroundcolorattributename:[Uicolor Whitecolor],nsparagraphstyleattributename:paragraphstyle}];    Returns the drawing of the new graphic UIImage *newimage= uigraphicsgetimagefromcurrentimagecontext ();    Uigraphicsendimagecontext (); return newimage;}

Find all the child views 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 File Size

//File Size-(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;}    Folder Size-(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 Stringbyappendingpathcompo            Nent:filename]; if ([FileManager Fileexistsatpath:fileabsolutepath]) {Long Long size = [FileManager Attributeso                Fitematpath:fileabsolutepath error:nil].filesize;            Foldersize + = size; }}} return foldersize;} 

UIView the set part rounded corners

CGRect rect = view.bounds; Cgsize Radio = Cgsizemake (30, 30);//fillet size Uirectcorner corner = uirectcornertopleft| uirectcornertopright;//the fillet position uibezierpath *path = [Uibezierpath bezierpathwithroundedrect:rect byRoundingCorners: Corner Cornerradii:radio]; Cashapelayer *masklayer = [[Cashapelayer alloc]init];//Create shapelayermasklayer.frame = View.bounds;masklayer.path = Path . cgpath;//set Path view.layer.mask = Masklayer;

Calculates the string character length, a Chinese character is counted two characters

Method One:-(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 two:-(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;}

Prevent scrolling view gestures from overwriting slide gestures

[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

+ (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

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 (@ "First request completed");        Dispatch_group_leave (Dispatchgroup);    });    Dispatch_group_enter (dispatchgroup);    Dispatch_after (Dispatch_time (Dispatch_time_now, (int64_t) (nsec_per_sec)), Dispatch_get_main_queue (), ^{        NSLog (@ "second request completed");        Dispatch_group_leave (Dispatchgroup);    });    Dispatch_group_notify (Dispatchgroup, Dispatch_get_main_queue (), ^ () {        NSLog (@ "request Complete");    });

Uitextfield every four bits plus a space to implement the proxy

-(BOOL) TextField: (Uitextfield *) TextField Shouldchangecharactersinrange: (nsrange) range replacementstring: ( NSString *) string{    //four-bit plus a space    if ([string isequaltostring:@ ""])    {        //delete 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 phone-installed apps

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")]);

In-app open system settings interface

iOS8 [[uiapplication sharedapplication] Openurl:[nsurl urlwithstring:uiapplicationopensettingsurlstring]];// If the app does not add permissions, the settings screen is displayed. If the app has added permissions (such as notifications), the app's settings screen is displayed. IOS8 before//Add a URL type and call the following code in the code to jump to the corresponding entry for the Settings page [[uiapplication sharedapplication] Openurl:[nsurl urlwithstring:@ " Prefs:root=wifi "]); optional values are as follows: 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=bluetoothdate & 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=safarisiri-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

Animation pause and start

-(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;}

Formatting numbers in the iOS version

With Nsnumberformatter, you can also set the format of the NSNumber output. 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);//output: [1223:403] Formatted number string:123,456,789// Where the Nsnumberformatter class has an attribute NumberStyle, which is an enumerated type, setting different values can output a different number format. The enumeration includes: TypeDef ns_enum (Nsuinteger, nsnumberformatterstyle) {Nsnumberformatternostyle = Kcfnumberformatternostyle, NS Numberformatterdecimalstyle = Kcfnumberformatterdecimalstyle, Nsnumberformattercurrencystyle =    Kcfnumberformattercurrencystyle, Nsnumberformatterpercentstyle = Kcfnumberformatterpercentstyle, Nsnumberformatterscientificstyle = Kcfnumberformatterscientificstyle, Nsnumberformatterspelloutstyle = kcfnumberformatterspelloutstyle};//the effect of each enumeration corresponding to the output number format is as follows: where the output of the third and last items differs depending on the locale of 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: 123,456,789

How to get the WebView all the picture address

uiwebview-(void) Webviewdidfinishload: (UIWebView *) webview{//Here is JS, the main purpose of achieving the acquisition of the URL static NSString * const JSGETIM    ages = @ "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];//Injection js method nsstring *urlresult = [WebView    stringbyevaluatingjavascriptfromstring:@ "GetImages ()"];    Nsarray *urlarray = [Nsmutablearray arraywitharray:[urlresult componentsseparatedbystring:@ "+"]]; URLRESURLT is to get all the images of the URL splicing; Murlarray is an array of all the URLs}//wkwebview-(void) WebView: (Wkwebview *) WebView Didfinishnavigation: (null_unspecified wknavigation *) navigation{static NSString * Const JSGETIMAGES = @ "function g    Etimages () {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); }];}

Gets the height of the WebView

CGFloat height = [[Self.webview stringbyevaluatingjavascriptfromstring:@ "Document.body.offsetHeight"] floatvalue];

Navigation bar becomes pure transparent

First method//navigation bar Pure transparent [Self.navigationbar setbackgroundimage:[uiimage new] forbarmetrics:uibarmetricsdefault];// Remove the black line at the bottom of the navigation bar self.navigationBar.shadowImage = [UIImage new];//the second method [[Self.navigationbar subviews] objectatindex:0]. Alpha = 0;

TabBarbecomes pure transparent

[Self.tabbar setbackgroundimage:[uiimage new]];self.tabbar.shadowimage = [UIImage new];

Navigationbar according to the sliding distance gradient color realization

First-(void) Scrollviewdidscroll: (Uiscrollview *) scrollview{cgfloat offsettoshow = 200.0;//swipe to fully display CGFloat alpha    = 1-(OFFSETTOSHOW-SCROLLVIEW.CONTENTOFFSET.Y)/offsettoshow; [[Self.navigationController.navigationBar subviews] objectatindex:0].alpha = alpha;}    The second type-(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];}    Generate a picture of a solid color-(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;}

Common code blocks for iOS development (2)