Xamarin Forms loop through list in a Grid

Question

I have a problem. I created the following class:

public class OrderBundles
{
    public int Id { get; set; }
    public NumOfTrades { get; set; }
    public List<Trade> Trades { get; set; }
}

public class Trade
{
    public int Id { get; set; }
    public string Date { get; set; }
    public string Action { get; set; }
    public string Coin { get; set; }
    public decimal Price { get; set; }
    public string ProfitUSDT { get; set; }
}

Now the bundles are working as follows: A bundle contains a SellOrder at first and then all Buy orders that are connected to a Sell.

Using that I want to create the following:

Now I already created a CollectionView with a ViewModel attached to it, but the problem then is, how can I loop inside the CollectionView row through the other list, so I can use the RowSpan?

Any ideas?

What do you mean to "loop inside the CollectionView, to use the RowSpan"? — Mihail Duchev, Jun 04 '20 at 07:30
As you can see I want a RowSpan on the SellProfit column, that needs to overlap all the buys below it. Now all the rows the ProfitUSDT has to overlap is inside the Trades list. That means that the `RowSpan of the ProfitUSDT = Trades.Count` If I only use a CollectionView I can't set the RowSpawn, because each row has its own grid. — A. Vreeswijk, Jun 04 '20 at 08:06

ColeX · Accepted Answer · 2020-06-05T15:19:12.003

1

Sorry , i misunderstood your question , so actually your problem is equal to is it possible to create bind on attached property(Grid.RowSpan) , xamarin does not support the feature for now .

Refer

Binding to Attached Properties in Xamarin Forms https://github.com/xamarin/Xamarin.Forms/issues/1647

Update

You could create a custom view as CollectionView.ItemTemplate , set rowSpan in method BindingContextChanged programatically .

   public CustomGrid()
    {
        InitializeComponent();
        this.BindingContextChanged += View1_BindingContextChanged;
    }

    private void View1_BindingContextChanged(object sender, EventArgs e)
    {
        OrderBundles obj = this.BindingContext;

        Grid.SetRowSpan(profitLabel, obj.Trades.Count);
    }

Sample link:https://github.com/ColeXm/GridSample

edited Jun 05 '20 at 15:19

answered Jun 04 '20 at 09:03

ColeX

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But I can have multiple sells, so multiple profit columns. This only works for 1 sell – A. Vreeswijk Jun 04 '20 at 12:00
So there is no way, to achieve what I want? No other View? – A. Vreeswijk Jun 04 '20 at 12:45
Can you show me what the full CustomView looks like? I mean, is the type a `ViewCell` or....? – A. Vreeswijk Jun 04 '20 at 21:37
Wait for my sample. – ColeX Jun 05 '20 at 05:42
I've uploaded the sample on github , please check it . – ColeX Jun 05 '20 at 15:17
There is only 1 bug with this.... If I create a much larger list and then scroll in it, it crashes after some new items have been shown or it crashes if I change the ListSource with a different list with different trades with the message: `Object reference not set to an instance of an object.` on the following line: `List list = obj.Trades;`. How can I fix this? – A. Vreeswijk Jun 06 '20 at 00:56
could you post the code Which can reproduce the error？ – ColeX Jun 06 '20 at 10:48
It is your code in the View1.xaml.cs, but with more data! – A. Vreeswijk Jun 06 '20 at 11:06
I have a ViewModel bound to the CollectionView and if you change the source of the CollectionView it also crashes – A. Vreeswijk Jun 06 '20 at 11:08
Can you please look at this question about your code: https://stackoverflow.com/questions/62242329/xamarin-forms-collectionview-doesnt-show-properly – A. Vreeswijk Jun 07 '20 at 07:43

Xamarin Forms loop through list in a Grid

1 Answers1

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