How to declare the data table column in c#?

Dinesh Santhalingam

class details
{
userdetails userdetails = new userdetails();
public string last;
public DataTable generalinfo = new DataTable();
public void loaddata(string [] path)
{
//Column were declared..............
/*generalinfo.Columns.Add("Name");
generalinfo.Columns.Add("Totalbike");
generalinfo.Columns.Add("Inuse");
generalinfo.Columns.Add("Time");*/
lines = path;
//do something.............
}
}

I have a data table .I wish to declare the column for my data table.But If i declared in loaddata its creating some error.Because Loaddata is Run every time.So the Error raised.

Error:Datacolumn were already belongs to a data table ...

How to declare it before the load data .Please solve my issue?Thanks in advance...

9 Replies

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

Rafnas T P9y ago
ok you are using variable and blocking the code.

Rafnas T P9y ago

check like this in same place

if(!generalinfo.Columns.Contains("Name"))
generalinfo.Columns.Add("Name");
if(!generalinfo.Columns.Contains("Totalbike"))
generalinfo.Columns.Add("Totalbike");
if(!generalinfo.Columns.Contains("Inuse"))
generalinfo.Columns.Add("Inuse");

if(!generalinfo.Columns.Contains("Time"))
generalinfo.Columns.Add("Time");

Dinesh Santhalingam9y ago
1. public void Method()
2. {
3. if (!_isExecutedFirst){
4. generalinfo.Columns.Add("Name");
5. generalinfo.Columns.Add("Totalbike");
6. generalinfo.Columns.Add("Inuse");
7. generalinfo.Columns.Add("Time");
8. _isExecutedFirst = true;}
9. }
10. method();
I got the solution.

Amit Gupta9y ago

@Dinesh

I think, there won't be issue while adding column at runtime.

Just need to check the column before adding

if (generalinfo.Columns["Totalbike"]==null)
generalinfo.Columns.Add("Totalbike");

Hope this helps

Rafnas T P9y ago

have you got output?

Dinesh Santhalingam9y ago

Yes you are right.@

Rafnas T P

Rafnas T P9y ago

sorry you have to declare window loaded or any function which loads first time.

Dinesh Santhalingam9y ago

public DataTable generalinfo = new DataTable();

generalinfo.columns.Add("Name");//Can't allow me to declare

Rafnas T P9y ago

declare outside the loaddata and check like below

public DataTable generalinfo = new DataTable();

//Column were declared..............
/*generalinfo.Columns.Add("Name");
generalinfo.Columns.Add("Totalbike");
generalinfo.Columns.Add("Inuse");
generalinfo.Columns.Add("Time");*/
lines = path;
//do something.............

public void loaddata(string [] path)
{

}