Convert generic list to dataset in C#

Question

I have a Generic list of Objects. Each object has 9 string properties. I want to turn that list into a dataset that i can pass to a datagridview......Whats the best way to go about doing this?

Answer 1

You could create an extension method to add all property values through reflection:

public static DataSet ToDataSet<T>(this IList<T> list)
{
    Type elementType = typeof(T);
    DataSet ds = new DataSet();
    DataTable t = new DataTable();
    ds.Tables.Add(t);

    //add a column to table for each public property on T
    foreach(var propInfo in elementType.GetProperties())
    {
        t.Columns.Add(propInfo.Name, propInfo.PropertyType);
    }

    //go through each property on T and add each value to the table
    foreach(T item in list)
    {
        DataRow row = t.NewRow();
        foreach(var propInfo in elementType.GetProperties())
        {
            row[propInfo.Name] = propInfo.GetValue(item, null);
        }
    }

    return ds;
}

Answer 2

You may want to check out

http://www.codeproject.com/KB/vb/List2DataSet.aspx

Gives a few different approaches.

Answer 3

I've written a small library myself to accomplish this task. It uses reflection only for the first time an object type is to be translated to a datatable. It emits a method that will do all the work translating an object type.

Its the fastest solution i know (thats why i developed it :-) ). You can find it here: ModelShredder on GoogleCode

Currently it is only supporting translation to a DataTable. As you phrased your question, this should be sufficient. Support for DataSets (think of a simple reverse ORM) is already developed, it will be released in two weaks when i am back from vacation :-)

Answer 4

Have you tried binding the list to the datagridview directly? If not, try that first because it will save you lots of pain. If you have tried it already, please tell us what went wrong so we can better advise you. Data binding gives you different behaviour depending on what interfaces your data object implements. For example, if your data object only implements IEnumerable (e.g. List), you will get very basic one-way binding, but if it implements IBindingList as well (e.g. BindingList, DataView), then you get two-way binding.

Answer 5

I apologize for putting an answer up to this question, but I figured it would be the easiest way to view my final code. It includes fixes for nullable types and null values :-)

    public static DataSet ToDataSet<T>(this IList<T> list)
    {
        Type elementType = typeof(T);
        DataSet ds = new DataSet();
        DataTable t = new DataTable();
        ds.Tables.Add(t);

        //add a column to table for each public property on T
        foreach (var propInfo in elementType.GetProperties())
        {
            Type ColType = Nullable.GetUnderlyingType(propInfo.PropertyType) ?? propInfo.PropertyType;

            t.Columns.Add(propInfo.Name, ColType);
        }

        //go through each property on T and add each value to the table
        foreach (T item in list)
        {
            DataRow row = t.NewRow();

            foreach (var propInfo in elementType.GetProperties())
            {
                row[propInfo.Name] = propInfo.GetValue(item, null) ?? DBNull.Value;
            }

            t.Rows.Add(row);
        }

        return ds;
    }

Answer 6

One option would be to use a System.ComponenetModel.BindingList rather than a list.

This allows you to use it directly within a DataGridView. And unlike a normal System.Collections.Generic.List updates the DataGridView on changes.