[Solved] Grid behaves oddly when column names are stringed ints ...

[scott]

Hi.

I have a simple grid binding a DataTable.  The column names in the DataTable are random ints converted to strings and the values are more random ints.  If I leave it like that, then a 10x10 DataTable takes 25 seconds to bind and shows no data ... ?

If I prefix the DataTable column names with any character(s) except a digit, then the grid works as expected, bindind and displaying the data in less than a second.

Thoughts ? Thanks -
Scott

<UserControl x:Class="WideGridView.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
    mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
  <Grid x:Name="LayoutRoot">
        <StackPanel>
            <StackPanel Orientation="Horizontal">
                <telerik:RadButton Content="Build Table" Click="RadButton_Build" Width="100"
                                   HorizontalAlignment="Left" Background="Wheat"/>
                <TextBlock Text="Rows:" VerticalAlignment="Center" Margin="5,0,0,0"/>
                <TextBox Name="NumRows" Width="50" Text="10" Margin="5,0,0,0"/>
                <TextBlock Text="Columns:" VerticalAlignment="Center" Margin="5,0,0,0"/>
                <TextBox Name="NumColumns" Width="50" Text="10" Margin="5,0,0,0"/>
                <TextBlock Text="Column Name Prefix:" VerticalAlignment="Center"  Margin="5,0,0,0"/>
                <TextBox Name="ColumnNamePrefix" Width="50" VerticalAlignment="Center" Margin="5,0,0,0"/>
                <telerik:RadButton Name="BindButton" Content="Bind to Grid" Background="Wheat" Width="100" IsEnabled="False"
                                   Click="RadButton_Bind" Margin="5,0,0,0"/>
                <TextBlock Name="Message" Margin="5,0,0,0" VerticalAlignment="Center"/>
            </StackPanel>
            <telerik:RadGridView Name="myGrid" Width="{Binding ElementName=LayoutRoot, Path=Width}"
                                 MaxHeight="500" HorizontalAlignment="Left"/>
        </StackPanel>
    </Grid>
</UserControl>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;

using Telerik.Data;

namespace WideGridView
{
    public partial class MainPage : UserControl
    {
        DataTable myTable;
        DateTime timeThen, timeNow;
        Random R = new Random(DateTime.Now.Second);

        public MainPage()
        {
            InitializeComponent();
        }

        private void RadButton_Bind(object sender, RoutedEventArgs e)
        {
            timeThen = DateTime.Now;
            myGrid.ItemsSource = myTable;

            Deployment.Current.Dispatcher.BeginInvoke(() =>
                {
                    timeNow = DateTime.Now;
                    Message.Text = string.Format("Time to set Grid.ItemsSource was: {0}", new TimeSpan(timeNow.Ticks - timeThen.Ticks));
                });

            BindButton.IsEnabled = false;
        }

        private void RadButton_Build(object sender, RoutedEventArgs e)
        {
            timeThen = DateTime.Now;
            int numColumns = Convert.ToInt32(NumColumns.Text);
            int numRows = Convert.ToInt32(NumRows.Text);

            List<string> columnNames = new List<string>();
            for (int i = 0; i < numColumns; i++)
                columnNames.Add(string.Format("{0}{1}",ColumnNamePrefix.Text, R.Next().ToString()));

            if (columnNames.Distinct().Count() != numColumns)
                MessageBox.Show("Try again.");

            myTable = new DataTable();
            for (int i = 0; i < numColumns; i++)
                myTable.Columns.Add(new DataColumn() { ColumnName = columnNames[i], DataType = typeof(int) });

            for (int i = 0; i < numRows; i++)
            {
                DataRow dr = myTable.NewRow();

                for (int j = 0; j < numColumns; j++)
                {
                    dr[columnNames[j]] = R.Next();
                }
                myTable.Rows.Add(dr);
            }

            BindButton.IsEnabled = true;

            Deployment.Current.Dispatcher.BeginInvoke(() =>
                {
                    timeNow = DateTime.Now;
                    Message.Text = string.Format("Time to build table was: {0}", new TimeSpan(timeNow.Ticks - timeThen.Ticks));
                });
        }
    }
}

[Pavel Pavlov]

Hi scott,

Can you please check  the VS output window for binding expression errors while running the app ?

All the best,
Pavel Pavlov
the Telerik team

[scott]

Hi Pavel - nothing unusual in the debug window.  My comlpete code is in the original post and may help you reproduce the issue - the workaround is simple so its a non issue for me.  Just thought you guys might want to know about it...

Regards -
Scott

[Pavel Pavlov]

Hello scott,

Unfortunately nothing can be done  to improve the situation. Internally the SL datatable tries to create dynamic properties with the names given for the columns.  The conflict is propertyname <-> numbers only string  which interferes with the binding mechanisms.  

As a workaround I may suggest to use prefixed properties , and display them in the headers without the prefixes ( e.g. using the Header property of the column) .

Best wishes,
Pavel Pavlov
the Telerik team