How to press button in View #1 to change the Label in View #2 (Xamarin iOS)

I when I press a button in view #1 (for example "PurpleFruitBtn") and I want to change the text in another view down the line (after a few other screens of other things) to display "Selection: Grape."

Have tried a few things, but they don't work.

How would more experienced people that know what they are doing do it?

Thanks,
A humbled kid who knows more and more that he doesn't know much.

3 Answers
3

You can define a string variable in View#2, and then put it in View#1 when you're switching to View#2，like this
enter image description here

When the page switch is complete, the label on the second page takes the variable of PhoneNumbers and displays it.

You can define a common class for transferring data between views:

using System;
namespace XamarinIosDataPass
public class CommonClass
public static string value;




Then when in view1, you update data when button is clicked:

partial void BtnSend_TouchUpInside(UIButton sender)
CommonClass.value = txtInput.Text;



And update the lable in View2 based on value of the Common class:

public override void ViewDidLoad()
base.ViewDidLoad();
lblDisplay.Text = CommonClass.value;



Please refer this link for more details.

Happy coding!

You can also use NSNotification to send message and pass value between two views.

NSNotification

in View #1

post the notification when you want to change the label in view#2

UIButton button = new UIButton(new CGRect(100, 300, 100, 50));
button.SetTitle("PurpleFruit",UIControlState.Normal);
button.SetTitleColor(UIColor.White, UIControlState.Normal);
button.BackgroundColor = UIColor.Blue;
button.TouchUpInside += (sender, e) =>


NSDictionary dic =NSDictionary.FromObjectAndKey(new NSString("value"),new NSString(button.TitleLabel.Text)) ;

NSNotification notification = NSNotification.FromName("ChangeValue",null,dic); //pass the string as a parameter

NSNotificationCenter.DefaultCenter.PostNotification(notification);

;


in view #2

Register the notification in the method ViewWillAppear

ViewWillAppear

public override void ViewWillAppear(bool animated)

base.ViewWillAppear(animated);

NSNotificationCenter.DefaultCenter.AddObserver(this,new Selector("ChangeValue:"),new NSString("ChangeValue") ,null);


[Export("ChangeValue:")]
public void ChangeValue(NSNotification notification)

Console.Write(notification.UserInfo.ObjectForKey(new NSString ("value")));
// now you can change the label.text



Notice :the name of notification must be same (just like ChangeValue in above code). Before posting you should register the notification firstly.Otherwise,view #2 can't receive the notification.

ChangeValue

For more details about NSNotification you can refer to here

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