How to make a ItemsWrapGrid in UWP using C#?

Question

Question : How can I make a Grid with a ItemsWrapGrid layout in C#?

Context

• UWP
• Visual Studio 2015
• Windows 10
• C#

Background

I know how to make it in XAML. After creating a new UWP application in Visual Studio 2015, the XAML is:

<Page
    x:Class="WrapGridTest001.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:WrapGridTest001"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    MinWidth="10"
    MinHeight="10"
    >

    <Grid x:Name="thisGrid">
        <GridView x:Name="thisGridView" IsItemClickEnabled="True">
            <GridView.ItemsPanel>
                <ItemsPanelTemplate>
                    <ItemsWrapGrid
                            x:Name="thisItemsWrapGrid"
                            Orientation="Horizontal"
                            MaximumRowsOrColumns="5"
                        />
                </ItemsPanelTemplate>
            </GridView.ItemsPanel>
            <TextBlock Text="#1"/>
            <TextBlock Text="#2"/>
            <TextBlock Text="#3"/>
        </GridView>
    </Grid>
</Page>

To make it programmatically, I've taken it out of the XAML:

<Page
    x:Class="WrapGridTest001.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:WrapGridTest001"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    MinWidth="10"
    MinHeight="10"
    >
</Page>

and tried to reproduce it in the Page 's constructor:

public MainPage()
{
    this.InitializeComponent();

    // Make the Grid and set it to be the Page's .Content:
    Grid grid = new Grid();
    this.Content = grid;

    // Make the GridView for the Grid, then set it:
    GridView gridView = new GridView();
    grid.Children.Add(gridView);

    // Make the ItemsPanelTemplate; necessary?
    ItemsPanelTemplate itemsPanelTemplate = new ItemsPanelTemplate();
    gridView.ItemsPanel = itemsPanelTemplate;

    // Make the ItemsWrapGrid.  Can't figure out how to set this.
    ItemsWrapGrid itemsWrapGrid = new ItemsWrapGrid();
    // When I traced the XAML version, its ItemsWrapGrid was apparently under
    //      gridView.ItemsPanelRoot
    // , but that's a get-only property.  I can't find a place to set it.

    // Add the TextBlock's with "#1", "#2", and "#3":
    for (int i = 1; i <= 3; ++i)
    {
        TextBlock textBlock = new TextBlock();
        textBlock.Text = "#" + i.ToString();
        gridView.Items.Add(textBlock);
    }

    // All done.  However, this Grid will show contents with a vertical alignment
    // rather than a horizontal one.
}

What additional code do I need to add to set the ItemsWrapGrid in C# as it was set in the XAML? Currently the C# code creates the ItemsWrapGrid , but the ItemsWrapGrid isn't actually set anywhere since every attempt to use it so far has resulted in a bug of some sort.

Answer 1

what you need is XamlReader

string template =
                "<ItemsPanelTemplate xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\" xmlns:x=\"http://schemas.microsoft.com/winfx/2006/xaml\"><ItemsWrapGrid VerticalAlignment = \"Top\" "
                + " ItemWidth = \""
                + itemWidth
                + "\" Orientation = \"Horizontal\"/></ItemsPanelTemplate> ";
yourgridview.ItemsPanel = (ItemsPanelTemplate)XamlReader.Load(template);

Answer 2

The fact is that the ItemsWrapGrid is the default panel for the GridView. It is not nice that the ItemsPanelTemplate cannot have the ItemsWrapGrid through a property and to use the XamlReader. After the gridview is loaded it gets at ItemsPanelRoot a default ItemsWrapGrid.

yourgridview.Loaded += yourgridview_Loaded;

and the function

private void yourgridview_Loaded(object sender, RoutedEventArgs e)
{
    var a = sender as GridView;
    var b = a.ItemsPanelRoot;
    var c = b as ItemsWrapGrid;
    c.MaximumRowsOrColumns = 2;c.Orientation = Orientation.Horizontal;
}