iOS开发block传值基本使用方法

/**A : .m*/

#import “controllerA.h”
#import "controllerB.h”

@interface controllerA ()

@property (nonatomic,
strong) UITextField *textFieldA;
@property (nonatomic,
strong) UIButton *buttonA;

@implementation controllerA
部分代码…………省略
按钮的跳转事件

- (void)buttonClick:(UIButton *)buttonA{
    controllerB *controller =[[controllerB
alloc]init];
    controller.returnTextBlock = ^(NSString *showText){
        self.textFieldA.text = showText;
    };
    [self
presentViewController:controller
animated:YES
completion:nil];
}
@end

/**B : .h*/

#import <UIKit/UIKit.h>
typedef void(^ReturnTextBlock)(NSString *showText);

@interface controller :
UIViewController
@property (nonatomic,
copy) ReturnTextBlock returnTextBlock;
@property (nonatomic,
strong) UITextField *textFieldB;
@end

/**B : .m*/

#import “controllerA.h”
#import "controllerB.h”

@interface controllerB ()

@property (nonatomic,
strong) UITextField *textFieldB;
@property (nonatomic,
strong) UIButton *buttonB;

@implementation controllerB
部分代码…………省略
按钮的跳转事件
- (void)buttonClick:(UIButton *)buttonB{
    if (self.returnTextBlock) {
        self.returnTextBlock(self.textFieldB.text);
    }
    [self
dismissViewControllerAnimated:YES
completion:nil];
}
@end