问题
I have a picker view with one component that I populated with an array of data. When the user presses a button, I want the selected data in that row to be stored in a variable so that I can send it to another view controller using a segue, where it will be displayed in a label. The only part I'm having trouble with is actually getting that data to be stored in order to be used somewhere else. I know that using a datePicker, I can do something like this to do what I want:
@IBAction func buttonPressed(sender: AnyObject) {
var chosenDate: NSDate = self.datePicker.date
}
This will store the date selected by the user in the var chosenDate, which is what I want for my pickerView when a button is pressed. I'm aware also that I can get that data in a pickerView using
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
The only problem with this is that it selects the data every single time a user changes the value, and it doesn't allow me to store the data in a variable outside the function for me to use it in my @IBAction func buttonPressed method. Thanks in advance!
回答1:
Alright, after trying different things I finally came up with a solution to my problem. It might not be what the more experienced developers do but it worked for me just like I wanted. Here is what I did:
@IBAction func saveButtonPressed(sender: AnyObject) {
var chosen = pickerView.selectedRowInComponent(0)
var chosenString = arrayPopulatingThePickerView[chosen]
}
I only have one component in the pickerView i need therefore when the button is pressed I store the row number of the component 0 in a variable, then I store the string in another variable by making it equal to the array I used to populate my picker view. I retrieve the row by passing it the chosen variable.
回答2:
You can create a function to store this date using NSUserDefaults. This way you can access it everywhere and anytime (even after closing the app).
func saveChosenDate(date:NSDate){
NSUserDefaults.standardUserDefaults().setObject(date, forKey: "chosenDate")
NSUserDefaults.standardUserDefaults().synchronize()
}
to load it:
func loadChosenDate()-> NSDate{
return NSUserDefaults.standardUserDefaults().objectForKey("chosenDate") as NSDate
}
to delete/reset the value of it:
NSUserDefaults.standardUserDefaults().removeObjectForKey("chosenDate")
NSUserDefaults.standardUserDefaults().synchronize()
save it
@IBAction func buttonPressed(sender: AnyObject) {
saveChosenDate(datePicker.date)
}
load it
let myDate = loadChosenDate()
来源：https://stackoverflow.com/questions/27770041/how-to-store-data-from-a-picker-view-in-a-variable-when-a-button-is-pressed