ios - 从一个 View Controller 传递字符串并将其显示在 ios 的 UITextView 中

Question

我已经尝试了一切可以做的事情来解决这个问题，因为我是新手，我没有得到明确的答案。 我有两个 View Controller 。我将textview的数据传递给第二个 Controller 并将其显示在UILabel中，没有问题。但现在我必须再次将标签文本发送到同一个 TextView 进行编辑。问题是，当我双击标签时，它会将我导航到第一个 View ，但不会在 TextView 中显示文本。

-(void)AddTextToCanvasWithGesture:(UITextView*)takenText
{

    CGRect rect = CGRectMake(35, 60,takenText.contentSize.width,takenText.contentSize.height);

    UIView *holderView = [[UIView alloc] initWithFrame:rect];

    rect.origin.x=0;
    rect.origin.y=0;
    UILabel *textLabel=[[UILabel alloc]initWithFrame:rect];


    [textLabel setText:takenText.text];
     self.text=takenText.text;

    [textLabel setTextColor:takenText.textColor];
    [textLabel setFont:[UIFont fontWithName:takenText.font.fontName size:takenText.font.pointSize]];
    [textLabel setNumberOfLines:0];
    [textLabel sizeToFit];
    [holderView setTag:1];
    [textLabel setTag:1+1];
    [holderView addSubview:textLabel];


    UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapped:)];

    [tapRecognizer setNumberOfTapsRequired:1];
    [tapRecognizer setDelegate:self];

    [holderView addGestureRecognizer:tapRecognizer];



    tapRecognizer = nil;

    UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(LaunchText)];

    [doubleTapRecognizer setNumberOfTapsRequired:2];
    [doubleTapRecognizer setDelegate:self];


    [holderView addGestureRecognizer:doubleTapRecognizer];
    holderView.userInteractionEnabled=YES;


    [tapRecognizer requireGestureRecognizerToFail:doubleTapRecognizer]; 

}

我必须将此标签的文本发送到第二 View Controller 的 TextView

-(void) LaunchText{

    [self update:self.text];
      [self performSegueWithIdentifier:@"textAdd" sender:self]; 
}

-(void)update:(NSString*)string{

    TextAddViewController *txt=[[TextAddViewController alloc]init];

    txt.usingText.text=string;
}

我在第二个 View 中获取这个字符串

-(void)viewDidLoad
{
    [super viewDidLoad];

    ViewController *vm=[[ViewController alloc]init];
    self.usingText.text=vm.text;
}

Answer 1

在 SecondViewController 中重写以下方法，并将 UILabel 值传递给 FirstViewController。

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    NSLog(@"prepareForSegue is called");
    if ([[segue identifier] isEqualToString:@"CONTROLLER_SEGUE"])  {

        TextAddViewController *vc = [segue destinationViewController];
        [vc.usgingText setText:@"SOME TEXT"];
    }
}