iOS project development error-prone Knowledge Point summary Han Junqiang's Blog

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Click Return to cancel TextView's responder

-(BOOL) Textfieldshouldreturn: (Uitextfield *) textfield{    [_contacttextfiled Resignfirstresponder];    return YES;} -(BOOL) TextView: (Uitextview *) TextView Shouldchangetextinrange: (nsrange) Range Replacementtext: (NSString *) text{       if ([text isequaltostring:@ "\ n"]) {               [TextView resignfirstresponder];        [_contacttextfiled Becomefirstresponder];        return YES;    }    return YES;}

iOS One line of code removes all child views from the parent view The main use of a makeObjectsPerformSelector: function here. This function can be used in many scenarios to simplify the code.

[Xxxview.subviews makeobjectsperformselector: @selector (Removefromsuperview)];

resolves an issue that refreshes a single cell or section flash:

        [UIView Setanimationsenabled:no];        [_listtable beginupdates];        [_listtable reloadsections:[nsindexset indexSetWithIndex:indexPath.section] Withrowanimation: Uitableviewrowanimationnone];        [_listtable endupdates];        [UIView Setanimationsenabled:yes];

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Draw the following curves:

    UIView *mycustomview = [[UIView alloc]initwithframe:cgrectmake (0, 204,kscreenwidth, +)];    Mycustomview.backgroundcolor = [Uicolor whitecolor];    [View Addsubview:mycustomview];       Uibezierpath *bezierpath = [Uibezierpath Bezierpath];    [Bezierpath Movetopoint:cgpointmake (0,0)];    [Bezierpath addcurvetopoint:cgpointmake (mycustomview.width, 0) controlpoint1:cgpointmake (0, 0) ControlPoint2: Cgpointmake (MYCUSTOMVIEW.WIDTH/2, +)];    [Bezierpath Addlinetopoint:cgpointmake (Mycustomview.width, Mycustomview.height)];    [Bezierpath addlinetopoint:cgpointmake (0, Mycustomview.height)];    [Bezierpath Closepath];       Cashapelayer *shaplayer = [Cashapelayer layer];    Shaplayer.path = Bezierpath.cgpath;    MyCustomView.layer.mask = Shaplayer;    MyCustomView.layer.masksToBounds = YES;

When you use Uisearchcontroller to implement the search bar in UITableView, when the search box has been activated and pushed into the new VC, there will be a search box overlap: That is Definespresentationcontext this boolean value!

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the hidden and disappearing of TabBar:

-(void) Hidestabbar: (BOOL) hidden{[UIView Beginanimations:nil context:null];       [UIView setanimationduration:0];            For (UIView *view in self.tabBarController.view.subviews) {if ([View Iskindofclass:[uitabbar class]]) { if (hidden) {[View Setframe:cgrectmake (view.frame.origin.x, [UIScreen Mainscreen].bounds.size.heigh            T, View.frame.size.width, View.frame.size.height)]; }else{[View Setframe:cgrectmake (view.frame.origin.x, [UIScreen mainscreen].bounds.size.height-49, VIEW.F            Rame.size.width, View.frame.size.height)];                    }}else{if ([View iskindofclass:nsclassfromstring (@ "Uitransitionview")]) {if (hidden) { [View Setframe:cgrectmake (view.frame.origin.x, VIEW.FRAME.ORIGIN.Y, View.frame.size.width, [UIScreen Main                Screen].bounds.size.height)]; }else{[View Setframe:cgrectmake (View.frame.origin.x, view.frame.orIGIN.Y, View.frame.size.width, [UIScreen mainscreen].bounds.size.height-49)]; }}}} [UIView commitanimations];}

Gets the partition and number of rows on the cell where the button is located:

    UIView *view = [Sender Superview]; Get view    Gccollectgroupcelltableviewcell *cell = (gccollectgroupcelltableviewcell*) [view Superview] for parent views; Get cell    Nsindexpath *indexpath = [_listtable Indexpathforcell:cell];//Get cell corresponding partition    NSLog (@ "%@", detailarr[ indexpath.section-1][indexpath.row][@ "Comname"]);

Nsattributedstring and NSString Transfer:

    nsattributedstring * Attrstr = [[Nsattributedstring alloc] initwithdata:[_companyfileds.comname dataUsingEncoding: Nsunicodestringencoding] options:@{Nsdocumenttypedocumentattribute:nshtmltextdocumenttype} documentAttributes: Nil Error:nil];    _companyfileds.comname = attrstr.string;

Monitor Uitextfield changes:

Register for monitoring [[Nsnotificationcenter defaultcenter]postnotificationname:uitextfieldtextdidchangenotification Object:nil]    ; [[Nsnotificationcenter defaultcenter]addobserver:self selector: @selector (changeforkeyword:) Name: Uitextfieldtextdidchangenotification object:nil];//Monitor _pagetextfield.text Change-(void) Changeforkeyword: ( Nsnotification *) sender{[self checknum:_pagetextfield.text];} -(BOOL) Checknum: (NSString *) str{nsstring *regex = @ "^[0-9]+ (. [    0-9]{2})? $ ";    Nspredicate *pred = [Nspredicate predicatewithformat:@ "Self MATCHES%@", regex];    BOOL IsMatch = [pred evaluatewithobject:str]; if (!ismatch && _pagetextfield.text.length>0) {Uialertview *alertview = [[Uialertview alloc]initwithtit        Le:nil message:@ "page number can only enter the number Oh" delegate:self cancelbuttontitle:@ "re-enter" Otherbuttontitles:nil, nil];        Alertview.delegate = self;        [Alertview show];    return NO; } return YES;

Listen for Uitextfield click events

[[Nsnotificationcenter defaultcenter]postnotificationname:uitextfieldtextdidbegineditingnotification Object:nil] ;         [[Nsnotificationcenter defaultcenter]addobserver:self selector: @selector (enteredited:) Name: Uitextfieldtextdidbegineditingnotification Object:nil];  -(void) enteredited: (Nsnotification *) Sender {     

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Resolution added to Parent view gestures that affect child view gestures: (gesture conflict)

Method One: #pragma mark--uigesturerecognizerdelegate-(BOOL) Gesturerecognizer: (Uigesturerecognizer *) Gesturerecognizer Shouldreceivetouch: (Uitouch *) touch{    if ([Touch.view Iskindofclass:[uibutton class]]| | [Touch.view Iskindofclass:[uitableviewcell class]]| | [Touch.view Iskindofclass:[uitextfield class]]| | [Touch.view Iskindofclass:[uitextview class]])    {        return NO;    }    return YES;}

Method Two://uiview the Exclusivetouch property//By setting [self setexclusivetouch:yes], can achieve the same interface multiple controls accept the event when the exclusivity, so as to avoid some problems.

Uitextfield border Style and content adjustment:

1. Set the time in the IB remember to choose a borderless, or you can set up, are not valid, is also a pit dead.  _textboxname.layer.borderwidth=1.0f;    _textboxname.layer.bordercolor=[uicolorcolorwithred:0xbf/255.0fgreen:0xbf/255.0fblue:0xbf/255.0falpha:1]. Cgcolor;   2. The distance from the left border of the Uitextfield Chinese character    _textboxname.leftview=[[uiviewalloc] Initwithframe:cgrectmake (0,0, 16,51)];    _textboxname.leftviewmode=uitextfieldviewmodealways;

Picture Rotation Control:

#pragma mark-----Update button Animation-(void) Rotate360degreewithimageviews: (Uiimageview *) myviews{    cabasicanimation * Rotationanimation = [cabasicanimation animationwithkeypath:@ "Transform.rotation.z"];    Rotationanimation.tovalue = [NSNumber numberwithfloat:m_pi * 2.0];    Rotationanimation.duration = 1.0;    rotationanimation.cumulative = yes;rotate360degreewithimageviews    rotationanimation.repeatcount = 100000;    [Myviews.layer addanimation:rotationanimation forkey:@ "Rotationanimation"];} [Myviews.layer removeallanimations]; Stop it

Change the cell's selected color:

Cell.selectedbackgroundview = [[UIView alloc] initWithFrame:cell.frame]; Cell.selectedBackgroundView.backgroundColor = Color_backgroundview; do not need any color to set this: Cell.selectionstyle = Uitableviewcellselectionstylenone;

Rounding Problem:

Objective-c expands C, and naturally many usages are consistent with C. For example, the floating-point number is converted into integers, there are four cases. 1. Simple rough, direct conversion of float F = 1.5; int A; A = (int) F; NSLog ("A =%d", a); the output is 1. (int) is a forced type conversion that discards the decimal part of a floating-point number. 2. Gaussian function, rounding down float f = 1.6; int A; A = Floor (f); NSLog ("A =%d", a); the output is 1. The floor () method is rounded down, similar to the Gaussian function in mathematics []. Gets the largest integer that is not greater than the floating-point number, for a positive number is the part of the floating-point number, for the complex number, discard the floating-point part after the minus 1.3.ceil function, rounding up. float F = 1.5; int A; A = Ceil (f); NSLog ("A =%d", a); the output is 2. The Ceil () method is rounded up to get the smallest integer not less than the floating-point number, and for positive numbers it discards the floating-point number and adds 1, which is the part of the floating-point number that is discarded for the plural. 4. Rounding by forcing type conversions. float F = 1.5; int A; A = (int) (f+0.5); NSLog ("A =%d", a);

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iOS project development error-prone Knowledge Point summary Han Junqiang's Blog