Question

I have a method somewhat similar to the one written bellow(this is just a pseudo-code I am working in C#):

function GenerateChart(DataTable dt)
{
    DataTable dtChartTable = dt;
    dtChartTable.DefaultView.Sort = "SomeColumnName";
    //remaining functionality
}

what this above code does is it also sorts the records in dt. I am not getting why it is doing so. Just as a note: this function is called from two different places. at one place I am sending a Datatable object and at the other the Datatable is directly refered from the one stored in session.

Answer 1

That’s right.
You are setting the dtChartTable variable to the same memory represented by the dt variable.
So, sorting the dtChartTable affects the same DefaultView property used by the second .

If you don’t want this behavior you could create a copy of dt using

DataTable dtChartTable = dt.Copy();

but this is costly because in this way every datarow is duplicated.
Another possibility is creating a new DataView

DataView view = new DataView(dt);
view.Sort = "SomeColumnName";  
......

this doesn’t affect the original dt.DefaultView and you can process your datarowview from this new DataView