Pass data with prepareForSegue

问题

Im trying to pass data from viewController 1 to viewController2, I have 2 buttons and 1 segue(therefore there is one segue identifier) for those 2 buttons, each button when pressed should show: 1 label to show the title and 1 textView to show a definition, I am having troubles to show its own data of each word; I know it has to be the some code referencing the SENDER in the performSegueWithIdentifier, but I don't know how to do it.

I appreciate your help !!! thanks.

here is my code

class ViewController: UIViewController {

    @IBAction func AbstractionBtn(sender: AnyObject) {
        performSegueWithIdentifier("ShowDefinition", sender: "Abstraction")
    }

    @IBAction func binarySystemBtn(sender: AnyObject) {
        performSegueWithIdentifier("ShowDefinition", sender: "Binary System")

    }

 override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if (segue.identifier == "ShowDefinition") {
            if let destinationViewController = segue.destinationViewController as? EnglishViewController {
                destinationViewController.titleMsg = "Abstraction"
                destinationViewController.definitionMsg = "Abstraction Definition"
            }
    } else if(segue.identifier == "ShowDefinition"){if let destinationViewController = segue.destinationViewController as? EnglishViewController {
            destinationViewController.titleMsg = "Binary System"
            destinationViewController.definitionMsg = "Binary System Definition"
            }
        }    
}

回答1:

You have correctly passed the definition as a String in the sender parameter in performSegueWithIdentifier. You just need to use its value in prepareForSegue, but first you must cast it from AnyObject? back to a String.

Your code could be something like:

class ViewController: UIViewController {
    @IBAction func AbstractionBtn(sender: AnyObject) {
        performSegueWithIdentifier("ShowDefinition", sender: "Abstraction")
    }

    @IBAction func binarySystemBtn(sender: AnyObject) {
        performSegueWithIdentifier("ShowDefinition", sender: "Binary System")
    }

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if (segue.identifier == "ShowDefinition") {
            if let destinationViewController = segue.destinationViewController as? EnglishViewController {
                if let definition = sender as? String {
                    if definition == "Abstraction" {
                        destinationViewController.titleMsg = "Abstraction"
                        destinationViewController.definitionMsg = "Abstraction Definition"
                    } else if definition == "Binary System" {
                        destinationViewController.titleMsg = "Binary System"
                        destinationViewController.definitionMsg = "Binary System Definition"
                    }
                }
            }
        }
    }
}

回答2:

Try this one

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
{
    if (segue.identifier == "ShowDefinition")
    {
        if let destinationViewController = segue.destinationViewController as? EnglishViewController
        {
             var btn = sender as! UIButton
            if btn.tag == 1
            {
                destinationViewController.titleMsg = "Abstraction"
                destinationViewController.definitionMsg = "Abstraction Definition"
            }
            else
            {
                destinationViewController.titleMsg = "Binary System"
                destinationViewController.definitionMsg = "Binary System Definition"

            }

        }
    }
}

And set button tag like this

AbstractionBtn.tag = 1
binarySystemBtn.tag = 2

Now Call for segue like this

@IBAction func AbstractionBtn(sender: AnyObject) {
performSegueWithIdentifier("ShowDefinition", sender:sender)
}

回答3:

Create a var named titleMsg and definitionMsg. In each @IBAction method set the appropriate title message to self.titleMsg and similarly for self.definitionMsg.

After that call,

performSegueWithIdentifier("ShowDefinition", sender: self)

And then override,

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "ShowDefinition" {
        let destinationVC = segue.destinationViewController as? EnglishViewController
        destinationVC.titleMsg = self.titleMsg
        destinationVC.definitionMsg = self.definitionMsg
    }
}

Hope that helped!

来源：https://stackoverflow.com/questions/39955344/pass-data-with-prepareforsegue

标签

ios

swift

swift2

sender