ios 以编程方式推送 Controller View ，无需 Storyboard或 xib

Question

在 ViewControllerA 中，我现在有一个包含三行数据的表(三个消息)。单击一行，我试图将其中一行的文本(名称)推送到 ViewControllerB。我遇到的问题是我正在尝试以编程方式执行所有操作，而不是使用 Storyboard ID 或 Storyboard segues。这可能吗？这是我的。

ViewControllerA m.

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
  Messages *cell = (Messages *)[tableView cellForRowAtIndexPath:indexPath];
  NSString *from = [NSString stringWithFormat:@"%@", cell.from.text];
  ViewControllerB *VCB = [[ViewControllerB alloc]init];
  VCB.from = from;
  [self.navigationController pushViewController:VCB animated:YES];
  //using this^ creates a new view controller with a black screen but passes the variable
  //[self performSegueWithIdentifier:@"pushMessage" sender:self];
  using this^ shows my ViewControllerB perfectly but the value isn't set
}

ViewControllerB h.

@property (strong, nonatomic) NSString *from;

ViewControllerB m.

-(void)viewDidLoad{
    NSLog(@"%@", from);
}

有没有办法在不在 VCA 中启动新的 viewcontrollerB 并获得正确的推送动画的情况下执行此操作？

Answer 1

我相信我明白你在问什么，你几乎走在了正确的轨道上。您说当您使用 [self performSegueWithIdentifier:@"pushMessage"sender:self]; 时它会起作用，但未设置该值。

因此，在您的 header 中声明一个 NSString“from”，并在前面的代码中删除 [self.navigationController pushViewController:CVC animated:YES];

//ViewControllerA.h

@property (copy, nonatomic) NSString *from;



//ViewControllerA.m

@synthesize from;

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
  Messages *cell = (Messages *)[tableView cellForRowAtIndexPath:indexPath];
  from = [NSString stringWithFormat:@"%@", cell.from.text];

  [self performSegueWithIdentifier:@"pushMessage" sender:self];
}

然后你需要使用prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender

 //ViewControllerA.m

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

    if ([[segue identifier] isEqualToString:@"pushMessage"]) {

        ViewControllerB *vcb = [segue destinationViewController];

        [vcb setFrom:[self from]];
    }

}

---

编辑

嗯，我觉得这是一种非常错误的做法。但是，这将满足您在问题中提出的所有条件。我已经检查过，这确实有效:

首先，转到您的 Storyboard，单击 View Controller B，单击 identity inspector 并更改 Storyboard ID。同时单击“使用 Storyboard ID”的复选标记。

在你的 ViewControllerA 中:

//ViewControllerA.h

- (void)callViewControllerWithCellString:(NSString *)str;

//ViewControllerA.m

- (void)callViewControllerWithCellString:(NSString *)str
{
    NSString * storyboardName = @"Main";

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardName bundle: nil];
    SecondViewController * vc = [storyboard instantiateViewControllerWithIdentifier:@"ViewControllerB"];
    [vc setFrom:str];

    [[self navigationController] pushViewController:vc animated:YES];

}


-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    Messages *cell = (Messages *)[tableView cellForRowAtIndexPath:indexPath];
    NSString *from = [NSString stringWithFormat:@"%@", cell.from.text];

    [self callViewControllerWithCellString:from];
}