Validating a value for a DataColumn

I'm using a DataGrid with edit functionalities in my project. It's handy, compared to having to edit its source data manually, but sadly, that 开发者_运维百科means that I'll have to deal with validating user input a bit more.

And my problem is basically just that. When I set my DataGrid to EDIT mode, modify the values and then set it to UPDATE, what is the best way to check if a value that I've entered is, in fact, compatible with the corresponding column's data type?

i.e. (simple example)

// assuming
DataTable dt = new DataTable();
dt.Columns.Add("aa",typeof(System.Int32));

DataGrid dg = new DataGrid();
dg.DataSource = dt;
dg.DataBind();

dg.UpdateCommand += dg_Update;

// this is the update handler
protected void dg_Update(object src, DataGridCommandEventArgs e)
{
    string newValue = (someValueIEnteredInTextBox);

    // HOW DO I CHECK IF [newValue] IS COMPATIBLE WITH COLUMN "aa" ABOVE?

    dt.LoadDataRow(newValue, true);
}

Thanks guys. Any leads would be so much help.

Can't you use a compare validator? it does check for the following datatypes

 String
 Double
 Date
 Currency
 Decimal

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.comparevalidator.aspx

perhaps try some of these links:

http://msdn.microsoft.com/en-us/library/aa984376(VS.71).aspx
http://msdn.microsoft.com/en-us/library/0ye0dkkw.aspx
http://forums.silverlight.net/forums/p/134948/301233.aspx
http://www.daniweb.com/forums/thread101030.html#