Dataset - assingnment of value to cell without effect

Hans Klose

Hi,
why does the following not work?

DataSet ds = new DataSet();
ds.ReadXml("D:\\test.xml");
ds.Tables[8].Rows[0].ItemArray[0] = "test"; // this assingment does not work.

Before assingnment the value was "XXXXX".
After assingment the value was still "XXXXX", but it shold be "test"

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Sam Hobbs14y ago

Also see the following. This is sand-alone code that can be used in a console program to play around with it. The code uses the Field extension method to show a field and the SetField extension method to modify the field value.

DataSet  ds = new  DataSet ();

DataTable  table = new  DataTable ("table" );

DataColumn  column = new  DataColumn ("field" , System.Type .GetType("System.String" ));

table.Columns.Add(column);

ds.Tables.Add(table);

//

DataRow  row = ds.Tables[0].NewRow();

row[0] = "xxxx" ;

ds.Tables[0].Rows.Add(row);

Console .WriteLine(ds.Tables[0].Rows[0].Field<string >(0));

ds.Tables[0].Rows[0].ItemArray[0] = "test" ;

Console .WriteLine(ds.Tables[0].Rows[0].Field<string >(0));

ds.Tables[0].Rows[0].SetField<string >(0, "test" );

Console .WriteLine(ds.Tables[0].Rows[0].Field<string >(0));

Vulpes14y ago
It doesn't work because the ItemArray property just gets a copy of all the column values for a particular row and puts them in an array.

Changing an element in this array won't change the corresponding column of the row because there's no binding between the two.

However, if you change the array and then reassign it to the ItemArray property, then it should work:

object[] oa = ds.Tables[8].Rows[0].ItemArray;
oa[0] = "test";
ds.Tables[8].Rows[0].ItemArray = oa;
Senthilkumar14y ago
Hi,

Try this...

ds.Tables[0].Rows[0]["address"] = "test";

For more info:

http://msdn.microsoft.com/en-us/library/tat996zc(v=vs.80).aspx
http://social.msdn.microsoft.com/forums/en-US/adodotnetdataproviders/thread/04b952fa-95d7-4413-98f8-53c0a57ccb23