IOS Block Interface Reverse Value small Demo

1. Declare the Block property in the. h file of the second view controller:

Define Block@property (nonatomic, copy) void (^nextviewcontrollerblock) (NSString *tftext); @interface Nextviewcontroller () @property (weak, nonatomic) Iboutlet Uitextfield *inputtf; @end-(Ibaction) Btnaction: (ID) Sender {//Determine if block is empty if (self). Nextviewcontrollerblock) {self.       Nextviewcontrollerblock (Self.inputTF.text);} [Self.navigationcontroller Popviewcontrolleranimated:yes];} 2. Get the second view controller in the first view and invoke the defined properties with the second view controller: @interface Aviewcontroller () @property (weak, nonatomic) Iboutlet UILabel * Nextvcinfolabel; @end -(Ibaction) btnclicked: (ID) Sender { NEXTVIEWCONTROLLER*NEXTVC = [[Nextviewcontroller alloc]init]; nextvc.nextviewcontrollerblock= ^ (NSString *tfText ) {  self.nextVCInfoLabel.text = Tftext; }; [Self.navigationcontroller PUSHVIEWCONTROLLER:NEXTVC animated:yes]; }

IOS Block Interface Reverse Value small Demo