Parallel ForEach on DataTable

user_94382 0
Viewed 65029

I would like to use the new Parallel.ForEach function to loop through a datatable and perform actions on each row. I am trying to convert the code below:

        foreach(DataRow drow in dt.Rows)
        {
           ...
           Do Stuff
           ...
        }

To this code:

        System.Threading.Tasks.Parallel.ForEach(dt.Rows, drow =>
                {
                    ...
                    Do Stuff
                    ...
                });

When I run the new code I get the error:

The type arguments for method 'System.Threading.Tasks.Parallel.ForEach(System.Collections.Generic.IEnumerable, System.Action)' cannot be inferred from the usage. Try specifying the type arguments explicitly.

What is the correct syntax for this?

parallel-processing c#-4.0
5 Answers

This is better than the accepted answer because this does not need to reference System.Data.DataSetExtensions:

 Parallel.ForEach(dt.Rows.Cast<DataRow>(), dr =>

To use ForEach with a non-generic collection, you can use the Cast extension method to convert the collection to a generic collection, as shown in this example.

user_24724210

This way we can use Parallel.ForEach for Data table.

DataTable dtTest = new DataTable();
            dtTest.Columns.Add("ID",typeof(int));
            dtTest.Columns.Add("Name", typeof(string));
            dtTest.Columns.Add("Salary", typeof(int));

            DataRow dr = dtTest.NewRow();
            dr["ID"] = 1;
            dr["Name"] = "Rom";
            dr["Salary"] = "2000";
            dtTest.Rows.Add(dr);

            dr = dtTest.NewRow();
            dr["ID"] = 2;
            dr["Name"] = "David";
            dr["Salary"] = "5000";
            dtTest.Rows.Add(dr);

            dr = dtTest.NewRow();
            dr["ID"] = 3;
            dr["Name"] = "Samy";
            dr["Salary"] = "1200";
            dtTest.Rows.Add(dr);

            Parallel.ForEach(dtTest.AsEnumerable(), drow =>
            {
                MessageBox.Show("ID " + drow.Field<int>("ID") + " " + drow.Field<string>("Name") + " " + drow.Field<int>("Salary"));
            });
user_137223670
Related