Agfdhyk

Our Xamarin.Forms app works online and offline by downloading an original database to the cell phone and then syncing the SQLite database with the online database.
Our users need a way to see if they are online and if the changes they made got uploaded to the online database. What I try to achieve is to show the sync status at the top of every ContentPage, so the users can see this information all the time while working with the app.

What I tried is this: create a class "SyncInfoContentPage" that inherits from ContentPage. All ContentPages I already wrote will now not inherit from ContentPage anymore but from SyncInfoContentPage.
The SyncInfoContentPage automatically takes its Content and replaces it with a new Stacklayout that includes the SyncInfo and the original content. By doing this I don't have to rewrite the 77 ContentPages we already have.

This code works fine on Android, but on iOS the SyncInfo is not visible and (even worse) my ContentPages that inherit from SyncInfoContentPage do not react to anything anymore.

Here is my code:

public class SyncInfoContentPage : ContentPage

    {

        private readonly Frame SyncInfo;



        public SyncInfoContentPage()

        {

            SyncInfo = BuildSyncInfo(); //Creates the frame with the sync Information

            PropertyChanged += SyncInfoContentPage_PropertyChanged;

        }



        private void SyncInfoContentPage_PropertyChanged(object sender, PropertyChangedEventArgs e)

        {

          // Add the SyncInfo Frame on top of the Content when the Content gets changed

            if (e.PropertyName.Equals("Content"))

            {

                bool change = false;

          // If the content already is a StackLayout, check if the SyncInfo already got added, so that theres no infinite loop.

                if (Content is StackLayout)

                {

                    var check = Content as StackLayout;

                    if (!check.Children.Contains(SyncInfo))

                    {

                        change = true;

                    }

                }

                else  // if the Content is no StackLayout, the SyncInfo Frame can't be inside the Content yet

                {

                    change = true;

                }



                if (change)

                {

                    var layout = Content;       // This is a reference, probably the error?

                    Device.BeginInvokeOnMainThread(() =>

                    {

                        Content = new StackLayout

                        {

                            Children = { SyncInfo, layout }

                        };

                    });

                }

            }

        }

    }

The problem is probably that iOS doesn't like this part:

var layout = Content;

Content = new StackLayout { Children = { SyncInfo, layout } };

Thanks in advance for your help and any suggestions :-)

I got it to work. The solution is simple but strange. You have to add the original Content after you added the SyncInfo status bar.

                    var layoutOld = Content; 

                    var layoutNew = new StackLayout

                    {

                        Children = { SyncInfo }

                    };

                    Content = layoutNew;

                    layoutNeu.Children.Add(layoutOld);