gridView的一个增加行的问题

C# code

    protected void btnAddCell_Click(object sender, EventArgs e)
    {

        data();
         
    }

    private void data()
    {
        DataTable dt = new DataTable();
        DataRow  row = null;
        TableCell cell = new TableCell();
        DataColumn field;

        if (dt.Rows.Count == 0)
        {
            for (int i = 0; i < 5; i++)
            {
                Random ran = new Random();
                cell = new TableCell();

                field = new DataColumn();
              
                
                row = dt.NewRow();
                
                row.Table.Columns.Add(field);
               
            }
            dt.Rows.Add(row);
            
        } 

        this.GridData2.DataSource = dt;
        this.GridData2.DataBind();

    }

我现在想点击增加行的时候就出现一行，在次点击就在这个基础上加一行，加下面。

------解决方案--------------------
private void data()
{
if(ViewState["Dt"]!=null)
{
//dt=ViewState["Dt"] as DataTable;
//NewROW()
//Row.add
//绑定
ViewState["Dt"]=dt;
}
else
{
DataTable dt = new DataTable();
DataRow row = null;
TableCell cell = new TableCell();
DataColumn field;

if (dt.Rows.Count == 0)
{
for (int i = 0; i < 5; i++)
{
Random ran = new Random();
cell = new TableCell();

field = new DataColumn();


row = dt.NewRow();

row.Table.Columns.Add(field);

}
dt.Rows.Add(row);

} 

this.GridData2.DataSource = dt;
this.GridData2.DataBind(); 
ViewState["Dt"]=dt;
}
}