Best way / practive creating complex layout in code behind

Question

Best way / practive creating complex layout in code behind

Thomas Klocker 1

I have a design question on how to implement the creation of complex layouts / controls in code behind. I have a Xamarin.Forms application which reads data from a configuration file.
This data is analyzed, and then a data form will be created out of this data.
For ex. the configuration file says: i need 20 entry fields, 5 date fields, 5 memo edits, 10 pickers and 1 datagrid.

Now i wanted to ask what´s the best practice on creating the layout. I want the controls be created asynchronously, so the page get´s displayed with a activity indicator until all controls / layout is finished and can be shown.
Do you have any recommodations or experience on creating complex page layouts asynchronously in code behind?
Would be awesome if you guys could share your thoughts about this.

Thanks
Tom

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,456 Reputation points Microsoft External Staff

2022-01-28T05:45:56.05+00:00

I'm not sure what's your configuration file , maybe it is json farmat. You said " i need 20 entry fields, 5 date fields, 5 memo edits, 10 pickers and 1 datagrid." In my opinion, you could try using Collectionview, then define item appearance and choose different item appearance at runtime.

Thomas Klocker 1

Thanks for your answer. The configuration file is a XML file which i read into some self designed objects. Let me show some (pseudo) code:

public class MyDataObject
{
    public String Label;
    public ControlTypes ControlType;

    public enum ControlTypes
    {
        TextEdit,
        DateEdit,
        MemoEdit
    }
}


public class MyViewModel
{
    public List<MyDataObject> _listOfObjects = new List<MyDataObjects>();

    public async Task RetrieveDataObjects()
    {
        //call API method to get data objects...
        _listOfObjects = await _api.GetListOfObjects();
    }
}


public class MyContentPage : ContentPage
{
    public async Task CreateControlsForPage()
    {
        foreach(var dataObject in _myViewModel.DataObjects)
        {
            Label label = new Label() { Text = dataObject.Label }
            switch(dataObject.ControlType)
            {
                case TextEdit:
                    //create textedit
                    break;

                case DateEdit:
                    ....
            }
        }
    }
}

Now i want to know what´s the best way to implement and call the CreateControlsForPage function.
In this function i parse the data of the view model and want to create all the controls asynchronously.

Hope you understand what i mean.

Regards
Tom

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,456 Reputation points Microsoft External Staff

2022-02-09T08:56:52.8+00:00

In my opinion, you get all data by this method ( await _api.GetListOfObjects(); ) ,you could try to call the CreateControlsForPage method in the callback medthod of api. Try to publish a message by MessagingCenter and subscribe to this message on MyContentPage .