iOS Block传值~demo
//联系人:石虎 QQ: 1224614774昵称:嗡嘛呢叭咪哄
/**
注意点: 1.看 GIF 效果图.
2.看连线视图的效果图.
3.看实现代码(直接复制实现效果).
4.下载demo链接:(点击或者是https://gitee.com/ShiHu132/BlockChuanZhi)
*/
一、GIF 效果图:
二、连线视图的效果图:
图1:
图2:
三、实现代码:
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==========================控制器1: ViewController.m
// ViewController.m
// Block传值~demo
//
// Created by 石虎 on 2017/9/22.
// Copyright © 2017年 石虎. All rights reserved.
//
#import "ViewController.h"
#import "SHBlockViewController.h"
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UILabel *blockLabel;
- (IBAction)blockClick:(UIButton *)sender;
@end
@implementation ViewController
//逆向传值
- (IBAction)blockClick:(UIButton *)sender {
SHBlockViewController *blockVC =[[SHBlockViewController alloc] init];
// 接收方只需要调用传输方的 block 方法
[blockVC showTheResultToFirst:^(NSString *secondString) {
self.blockLabel.text = secondString;
}];
[self presentViewController:blockVC animated:YES completion:nil];
}
- (void)viewDidLoad {
[super viewDidLoad];
}
@end
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控制器2: SHBlockViewController.m
//
// SHBlockViewController.m
// Block传值~demo
//
// Created by 石虎 on 2017/9/22.
// Copyright © 2017年 石虎. All rights reserved.
//
#import "SHBlockViewController.h"
#import "ViewController.h"
@interface SHBlockViewController ()
@property (weak, nonatomic) IBOutlet UITextField *startValueField;
- (IBAction)startValueClick:(UIButton *)sender;
@end
@implementation SHBlockViewController
//返回到上级界面
- (IBAction)startValueClick:(UIButton *)sender {
[self dismissViewControllerAnimated:YES completion:nil];
}
// block实际执行的内容
-(void)showTheResultToFirst:(SHBlockViewBlock)block {
self.passValue = block;
}
// 在即将消失 view时，将 block 方法的参数设置为文本框的内容
-(void)viewWillDisappear:(BOOL)animated {
if (self.passValue != nil) {
self.passValue(self.startValueField.text);
}
}
//退出键盘
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
[self.view endEditing:YES];
}
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