StoryBoard的简单应用

SB加载到内存

创建home.storyboard文件、然后通过代码加载到内存中。

//初始化initialViewController   (即Storyboard entry point的箭头指向的VC)
UINavigationController *homeVC = [[UIStoryboard storyboardWithName:@"home" bundle:nil] instantiateInitialViewController];

//加载home.storyboard里面指定Identifier的VC、（需要在SB文件中指定该VC的Identifier值）
HomeSearchResultViewController *searchVC = [[UIStoryboard storyboardWithName:@"home" bundle:nil] instantiateViewControllerWithIdentifier:@"HomeSearchResultVC"];
searchVC.keyword = @"sample";
[self.viewController.navigationController pushViewController:searchVC animated:YES];

SB里的VC跳转

VC中间的跳转可以使用segue来实现的。(需要在SB文件里去通过拖拽拉线连接VC之间的Segue、并指定Segue的id，这样才能正确的访问到SB中众多的Segue中的唯一一个)

使用segue转场时，会响应-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender方法。其中segue就是storyBoard转场控制对象，在参数segue中能够获取所要跳转的视图控制器，destinationViewController（目标vc），sourceViewController(源视图vc)。

一、不需要传递参数到目标VC的情况：

[self performSegueWithIdentifier:@"toLoginVC" sender:nil];

二、需要传递参数的情况：

//先调用performSegueWithIdentifier方法，然后自动触发prepareForSegue方法
[self performSegueWithIdentifier:@"toLoginVC" sender:nil];

//在当前的sourceViewController里面添加下面的prepareForSegue方法，在VC跳转前作参数传递的工作

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if ([segue.identifier isEqualToString:@"toLoginVC"]) {
        LoginViewController *loginVC = (LoginViewController *)segue.destinationViewController;
        loginVC.account = @"xxxxx";
    }
    
}

---

上面这种方式有一个痛点，就是跳转要有两处的代码，首尾分离，不便管理。
现在考虑把本来在prepareForSegue里面的代码和performSegueWithIdentifier方法聚合到一起，方便管理。
就有了下面这种方式去实现：

KBSegueSender *sender = [[KBSegueSender alloc] initWithSend:self prepareBlock:^(UIStoryboardSegue *segue) {
    BindPhoneViewController *bindPhoneVC = (BindPhoneViewController *)segue.destinationViewController;
    bindPhoneVC.wx_user_id = wxId;
}];
[self performSegueWithIdentifier:@"toBindPhoneVC" sender:sender];

KBSegueSender是定义的Model，用来包裹block的属性。

#import 

typedef  void(^PrepareBlock)(UIStoryboardSegue * segue) ;

@interface KBSegueSender : NSObject

@property(assign)id  sender;
@property(assign) PrepareBlock prepareBlock;

- (id)initWithSend:(id)sender prepareBlock:(PrepareBlock) block;

@end

#import "KBSegueSender.h"

@implementation KBSegueSender

- (id)initWithSend:(id)sender prepareBlock:(PrepareBlock) block {
    self = [super init];
    
    if (self) {
        self.sender = sender;
        self.prepareBlock = block;
    }
    
    return self;
    
}

@end

//通过Block将参数传递代码聚合起来，然后通过创建Category来在prepareForSegue去执行block，完成值得传递。

#import "UIViewController+KBAdditional.h"
#import "KBSegueSender.h"

@implementation UIViewController (KBAdditional)

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if([sender isKindOfClass:[KBSegueSender class]]) {
        KBSegueSender *segueSender = (KBSegueSender*)sender;
        segueSender.prepareBlock(segue);
    }
}

@end