如何将DataGrid数据保存到CSV文件而不重新枚举查询结果？

Question

I am using this command to get data from my query:

private void loadData()
    {
        numRows = 0;

        try
        {
            data = gpso.gpEntitiesObject.ExecuteStoreQuery<My_Class>(sql);

            dataGrid.ItemsSource = data;
            dataGrid.IsReadOnly = true;
            numRows = dataGrid.Items.Count;
            numRowsTB.Text = "Number of rows: " + numRows;

        }
        catch (Exception ex)
        {
            statusBarTB.Text = "exception: " + ex.Message;
        }
    }

Although this works and I see the data in my DataGrid, I am not able to save the data to a CSV file since I am trying to reenumerate the query result again, which is not allowed.

What would be the right way to get the data and save it to CSV? Should I use the DataGrid API to scroll trough the rows and get the data in a foreach() loop?

Here is my CSV function:

    public static string exportToCSV(IEnumerable<My_Class> data, string separator)
    {
        string ishod = "";
        string csvRed = "";

        ishod += "Key1" + separator + "Key2" + separator;
        ishod += "Key3" + separator + "Key4" + separator;

        ishod += "\n";

        foreach (My_Class item in data)
        {
            csvRed += item.Key1+ separator + item.Key2+ separator;
            csvRed += item.Key3+ separator + item.Key4+ separator;

            csvRed += "\n";

            ishod += csvRed;

            csvRed = "";
        }

        return ishod;
    } 

Answer 1

I followed @Clemens advice. I used

IEnumerable dataList = data.ToList<My_Class>(); 
dataGrid.ItemSource = dataList;

I then called

exportToCSV(dataList, "\t");

with dataList as parameter and it worked!