iOS Reverse Value--block method

The Rootviewcontroller code is as follows:

#import   "RootViewController.h" #import   "MyControl.h" #import   "SecondViewController.h" #define  kdebugprint nslog (@ "%s", __func__) @interface  RootViewController  () {     uilabel *_label;} @end @implementation rootviewcontroller/*  forward value   Create first interface     jump to second interface via first interface   If the second interface is oriented by the first boundary   pass value   forward value   Property pass value     second to first interface value   Reverse value    downlevel interface up to one level interface value--- "Reverse Value    Reverse value:   1. Proxy value   Downlevel interface to the TextField of the content   to   the upper level, then the subordinate interface can be delegated to the upper interface   Modify  label Value   Second interface (active side)   can develop a protocol   canonical proxy behavior,   first interface (passive side)   Compliance protocol   as   proxy      2. Single case  1. System Singleton  2. Custom singleton   3. Notification pass-through value   4.nsuserdefaults   5.block Transfer value   */-  (void) viewdidload {    [super  Viewdidload];    [self showui];} -  (void) Showui {    self.view.backgroundcolor = [uicolor graycolor];        _label =  [mycontrol creatlabelwithframe:cgrectmake (0, 30, 300, 30)  text:@ "XXX"];     _label.backgroundcolor = [uicolor yellowcolor];    [ self.view addsubview:_label];        uibutton *button =  [mycontrol creatbuttonwithframe:cgrectmake (10, 200, 300, 50)  target:self  SEL: @selector (btnclick:)  tag:201 image:nil title:@ "switch to second"];    [self.view  addsubview:button];} -  (void) Btnclick: (uibutton *) btn {    //Create a new second object each time you click the button        SecondViewController *svc = [[SecondViewController alloc]  init];        [svc setmyblock:^ (NSSTRING *TEXTSTR)  {         _label.text=textStr;    }];         [self presentViewController:svc animated:YES completion:nil];     [svc release];    }-  (void) didreceivememorywarning  {    [super didreceivememorywarning];    // dispose of  any resources that can be recreated.} @end

Secondviewcontroller Point h file declares the following code:

#import <uikit/uikit.h>//-----------typedef void (^changetextblock) (NSString *textstr); @interface    secondviewcontroller:uiviewcontroller{//void (^myblock) (NSString *textstr); Changetextblock _myblock;} Modify and get-(void) Setmyblock: (Changetextblock) block;-(changetextblock) myblock; @end

#import   "SecondViewController.h" #import   "MyControl.h" #define  kdebugprint nslog (@ "%s", __ func__) @interface  SecondViewController  () {    uitextfield *_textfield;} @end @implementation secondviewcontroller-  (void) dealloc {    kdebugprint;     [_myblock release];    [super dealloc];} -(void) Setmyblock: (Changetextblock) block{    if  (_myblock!=block)  {         [_myblock release];        _ myblock=[block copy];//copy block    }}-(changetextblock)  myBlock{     return _myblock;} -  (void) viewdidload {    [super viewdidload];     Self.view.backgroundcolor = [uicolor yellowcolor];    [self showui];} -  (void) shOwui {    uibutton *button = [mycontrol creatbuttonwithframe: CGRectMake (10, 30, 300, 30)  target:self sel: @selector (btnclick:)  tag:301  image:nil title:@ "Back"];    [self.view addsubview:button];         uibutton *button2 = [mycontrol creatbuttonwithframe: CGRectMake (10,200 , 300, 30)  target:self sel: @selector (btnClick2:)  tag:302  image:nil title:@ "Pass Value"];    [self.view addsubview:button2];             _textField = [MyControl  Creattextfieldwithframe:cgrectmake (10, 100, 300, 30)  placeholder:nil delegate:nil  tag:100];    [self.view addsubview:_textfield];} Keyboard-  (void) Touchesbegan: (nsset *) Touches withevent: (uievent *) EVent {    [_textfield resignfirstresponder];} -  (void) Btnclick: (uibutton *) btn {    //return to the previous level     [self  dismissviewcontrolleranimated:yes completion:nil];} -  (void) BtnClick2: (uibutton *) btn {    //Click Pass Value    To delegate block execution modify the value of the first interface label         if  (self.myblock)  {         //_myblock (_textfield.text);         //equivalent to the previous sentence         self.myblock (_textfield.text);     }else{        nslog (@ "no incoming block");         }} @end

iOS Reverse Value--block method