DataTable.DefaultView.Sort Doesn't Sort

Question

I am confused on DataTable.DefaultView.Sort. Here is the segment of the code I want to use it in.

actionLogDT.DefaultView.Sort = "StartDate";

foreach (CustomerService.ActionLogStartEndRow logRow in actionLogDT)
{
  // code here
}

The samples I have seen don't use the foreach loop and thus is confusing me on how to process this. It isn't sorting as I thought it should be.

I see that .DefaultView returns a view, and .Table gives a compile error.

Solution 1

I had to take a slightly different approach. This post was the closest I could find to get my code to work. Here is the working result:

actionLogDT.DefaultView.Sort = "StartDate";
DataView dv = actionLogDT.DefaultView;

foreach (DataRowView logRow in dv) { . . . }

From there I just have to cast the value back into it's proper type.

(string)logRow["Status"].ToString()

Solution 2

actionLogDT.DefaultView.Sort = "StartDate";

actionLogDT = actionLogDT.DefaultView.ToTable();

Solution 3

Sorting the view won't change the sort order of the data in the table, just the order in the view. It should work if you do your foreach on the view instead, casting the row from the DataRowView back to your strongly typed row.

foreach (DataRowView logRowView in actionLogDT.DefaultView)
{
    CustomerService.ActionLogStartEndRow logRow = logRowView.Row as CustomerService.ActionLogStartEndRow;
    // code here
}

Solution 4

foreach (var logRow in actionLogDT.DefaultView.ToDataTable()) { ... }

Solution 5

Additionally, Since it seemed like you wanted to loop through records, you can just loop through the dataRowView objects in the DefaultView.

foreach (DataRowView drv in table.DefaultView)
{
    string strValue = drv["ColumnName"].ToString();
    // its also worth mentioning that a DataRowView has a Row
    strValue = drv.Row["ColumnName"].ToString();
}

View more solutions

Comments

[Mike Wills]

Doing that gives me an "Unable to cast object of type 'System.Data.DataRowView' to type 'ActionLogStartEndRow'." error.

[Jeromy Irvine]

Does ActionLogStartEndRow derive from DataRow?

[Mike Wills]

@Jeromy - I am sure it does. I am using the .XSD data layer to accomplish all of this.

[Mike Wills]

Basically the same casting error. Unable to cast object of type 'System.Data.DataRow' to type 'ActionLogStartEndRow'.

[Jeromy Irvine]

OK, I updated the answer to account for the strongly typed row. This should hopefully do the trick for you.

[Mike Wills]

I don't understand your question.

[Mike Wills]

I'll try that next time I have this problem.

[Stuart Hallows]

Because the question was about sorting a datatable. To enumerate the sorted data you need to enumerate the view, not the table itself.

[Lukas]

Thank you! Just what I needed. Get a table, sort it, and use it while it's sorted a certain way.

[vapcguy]

Cast is redundant... .ToString() should be enough.

[storsoc]

Slightly different scenario/symptoms for me, but the .toTable() solved this for me. Thanks. In my case, I was applying the DefaultView.Sort expression just fine and seeing the sort take effect for DropDownList, but it wasn't taking effect for a DataGrid. YMMV: The DataGrid we're applying this to is a very basic read-only table that does not provide dynamic sorting, etc.

[FredyWenger]

I have ported code from vb.net (with DT.DefaultView.Sort) to c# asp-net core. In vb.net, the sort has worked without overwrite (.DefaultView.ToTable();). Your posting here did the trick - thanks!