Variable is not adding in the GridView RowBound function

Question

I want to add the openingBalace value in GridView1 GridView1_RowDataBoun() function. But it is not working. How can I do this. Please help.  Here is my Code : - 

 

long totalIncome = 0;

long totalExpense = 0;

long openingBalace;

public void gridview2_rowdatabound(object sender, GridViewRowEventArgs e)

{

if (e.Row.RowType == DataControlRowType.DataRow)

{

totalIncome += Convert.ToInt64(DataBinder.Eval(e.Row.DataItem, "income"));

totalExpense += Convert.ToInt64(DataBinder.Eval(e.Row.DataItem, "expense"));

openingBalace = totalIncome - totalExpense;

}

else if (e.Row.RowType == DataControlRowType.Footer)

{

lblOpeningBalance.Text = openingBalace.ToString();

}

else

{

lblOpeningBalance.Text = "0";

}

}

 

 

long totalReceived = 0;

long totalPayment = 0;

long TotalBalace = 0;

long sum = 0;

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)

{

if (e.Row.RowType == DataControlRowType.DataRow)

{

totalReceived += Convert.ToInt64(DataBinder.Eval(e.Row.DataItem, "income"));

totalPayment += Convert.ToInt64(DataBinder.Eval(e.Row.DataItem, "expense"));

TotalBalace = totalReceived - totalPayment;

}

else if (e.Row.RowType == DataControlRowType.Footer)

{

lblTotalReceive.Text = totalReceived.ToString();

lblTotalPayment.Text = totalPayment.ToString();

lblBalance.Text = TotalBalace.ToString();

}

else

{

lblTotalReceive.Text = "0";

lblTotalPayment.Text = "0";

lblBalance.Text = "0";

}

if (e.Row.RowType == DataControlRowType.DataRow)

{ 

 //Here I want to add the Variable

sum = openingBalace + Convert.ToInt64(DataBinder.Eval(e.Row.DataItem, "income")) -

Convert.ToInt64(DataBinder.Eval(e.Row.DataItem, "expense")) + sum;

e.Row.Cells[8].Text = sum.ToString();

}

}