Is there a graceful way to display a big 2 dimensional array in WPF like excel?

Question

I am working with a requirement for displaying a 2 dimensional array in a WPF window. The size of array can be up to 360*720. I have tried to use DataTable bound to a DataDrid, but it took so much time to load the grid and very RAM consuming. My example code is below.

public void SetData(double[][] array)
{   
    if(array.Length <= 0)
        return;
    DataTable table = new DataTable();
    for (int i = 0; i < array[0].Length; i++)
    {
        table.Columns.Add(i.ToString(), typeof(double));
    }
    for (int i = 0; i < array.Length; i++)
    {
        DataRow row = table.NewRow();
        for (int j = 0; j < array[i].Length; j++)
        {
            row[j] = array[i][j].ToString();
        }
        table.Rows.Add(row);
    }
    dataGrid.DataContext = table;
}

I created an array of double of which the dimension is 360 * 720 and called the SetData() method above. As a result, the RAM occupied by the program increased several GBs and very time consuming.

I wonder if there is a graceful way to solve this problem or there are some shortcomings in my code. Thank you.

DataGrids don't have to bind to DataTables, unless its 2002, you can use Object Lists, have you tried a one liner `dataGrid.DataContext = array;;`? Also no need to cast to string `array[i][j].ToString()` — Jeremy Thompson, Jan 21 '22 at 03:39
I could be mistaken, however, what your code shows and what your comments say are two different things. The code… `double[][] array` … is NOT necessarily a 2-dimensional array which is what you claim in your comments. This is a jagged array of arrays which is different than a true 2-dimensional array which would be defined as `double[,]`. You may find the following two questions useful… — JohnG, Jan 21 '22 at 03:50
[What are the differences between a multidimensional array and an array of arrays in C#?](https://stackoverflow.com/questions/597720/what-are-the-differences-between-a-multidimensional-array-and-an-array-of-arrays) … And … [Multidimensional Array](https://stackoverflow.com/questions/12567329/multidimensional-array-vs) — JohnG, Jan 21 '22 at 03:51
I am just saying that a true 2-dimensional 360*720 array is NOT a lot of data especially if they are only double values and should take less than second to load. — JohnG, Jan 21 '22 at 03:57
Take a look at Virtual List Views. They can handle millions of rows quite efficiently. https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.listview.virtualmode?view=windowsdesktop-6.0. It’s important that both the underlying data and UI elements that make up the grid are **virtualised** — , Jan 21 '22 at 03:59
Really really thank you all for the useful answers and comments! — Dream Land, Jan 21 '22 at 05:48
@JeremyThompson, one liner `dataGrid.DataContext = array;` won't do any good. Binding is more complicated than that. DataTable has *many* useful features (built-in filtering!) and still a viable choice in year 2022. — ASh, Jan 21 '22 at 08:01

score 0 · Answer 1 · answered Jan 21 '22 at 07:24

Thanks for all these useful answers and comments which helped me a lot. After doing some search, I seemed to find out the reason why my code costs so much time to render the DataGrid. I wrapped up the grid with a ScrollViewer before. I removed it and it went very well. Here is the link where I found the tip.WPF DataGrid is very slow to render.

Thank you all.

score -1 · Accepted Answer · answered Jan 21 '22 at 03:18

Create a separate class that can return the enumerator as data.

class ArrayVisitor : IEnumerable<double[]>
{
    private double[,] _data;

    public ArrayVisitor()
    {
    }

    public ArrayVisitor(double[,] data)
    {
        _data = data;
    }

    public double[,] Data
    {
        get { return _data; }
        set { _data = value; }
    }

    #region IEnumerable<double[]> Members

    public IEnumerator<double[]> GetEnumerator()
    {
        if (_data == null)
            throw new ArgumentException("Data cannot be null.", "Data");

        int len2d = _data.GetLength(1);

        for (int i = 0; i < _data.GetLength(0); i++)
        {
            double[] arr = new double[len2d];
            for (int j = 0; j < len2d; j++)
            {
                arr[j] = _data[i, j];
            }

            yield return arr;
        }
    }

    #endregion

    #region IEnumerable Members

    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
        return this.GetEnumerator();
    }

    #endregion
}

You can use Listview and Gridview as Databound controls.
  
   private void Bindng2DArrayToListview2
        (ListView listview, double[,] data, string[] columnNames)
    {
        Check2DArrayMatchColumnNames(data, columnNames);
    
        GridView gv = new GridView();
        for (int i = 0; i < data.GetLength(1); i++)
        {
            GridViewColumn col = new GridViewColumn();
            col.Header = columnNames[i];
            col.DisplayMemberBinding = new Binding("[" + i + "]");
            gv.Columns.Add(col);
        }
    
        ArrayVisitor arrayVisitor = new ArrayVisitor(data);
        listview.View = gv;
        listview.ItemsSource = arrayVisitor;
    }

Thank you so much! It really works! I learn a lot from your code. I need some time to understand what the difference is behind the code. Thank you! — Dream Land, Jan 21 '22 at 03:56
Pleasure! And Don't miss to UpVote answer if it helped you to any extent. Thank You. Happy Coding! — Sumit Sharma, Jan 21 '22 at 04:47

Is there a graceful way to display a big 2 dimensional array in WPF like excel?

2 Answers2