DataGridView sorting with nulls in DateTime column

Question

I\'ve got a DataGridView control in a Windows forms application. There are four columns with string data and three with DateTime data. I\'m adding the rows programmatically

Answer 1

Updated Answer: After looking at your posted answer, I see that you're checking for DBNull.Value in the cells. That may be the source of your problem since DBNull.Value can't be cast to a DateTime. If you're programmatically adding the rows, try replacing DBNull.Value with null (Nothing).

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Original Answer: Try doing this for each column that holds DateTime data, preferably before any data is loaded:

myDateTimeColumn.ValueType = GetType(DateTime)

According to MSDN, the ValueType property is "used when filtering or sorting the columns with respect to the contents of their cells." So I would be sure to set it for any column that allows sorting.

With this property set, the grid can be sorted on a column that has nulls and will force inserted/updated cells to be converted to DateTime.