现有两个视图（ViewController，ViewController1），从ViewController中带参数跳转到ViewController1，在ViewController1选中数据后带有效数据后退到ViewController中，委托实现上述功能。

项目：点击下载

一、ViewController主要代码

// 按钮点击事件
-(IBAction)clickSearchBtn:(id)sender {
    
    [[[UIApplication sharedApplication] keyWindow] endEditing:YES];
    
    ViewController1 *_viewController = [[[ViewController1 alloc] init] autorelease];
    _viewController.delegate = self;
    _viewController.transText = self.textField.text;
    
    [self.navigationController pushViewController:_viewController animated:YES];
}

// ViewController1Delegate 的代理方法
-(void)selectData:(NSString*)text{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [self.listArray removeAllObjects];
        for (int i=0; i<5; i++) {
            [self.listArray addObject:[NSString stringWithFormat:@"第%d行数据：%@_%d",i+1,text,arc4random_uniform(100)]];
        }
        dispatch_async(dispatch_get_main_queue(), ^{
            [self.dataTableView reloadData];
        });
    });
}

// ViewController1.h
// delegate写在#import之前，否则可能会Delegate Cannot find protocol declaration
@protocol ViewController1Delegate;
@protocol ViewController1Delegate <NSObject>

@optional
-(void)selectData:(NSString*)text;
@end

// ViewController1.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
    
    if ([self.delegate respondsToSelector:@selector(selectData:)]) {
        
        //通过委托协议传值
        [self.delegate selectData:[self.listArray objectAtIndex:indexPath.row]];
        [self.navigationController popViewControllerAnimated:YES];
    }
}

ios两视图间委托（delegate）传值