Accessing the TextBox Contents in Dynamically Created GridView - asp.net

Question

i created gridview dynamically,
which consists of Textboxes and buttonfield, on row command event of the gridview i want to access the content of textbox.
i am not able to access the textbox
here is my code
protected void FillGridListTollCollection()
{
TollCollectionBLLC tollcollectionBLLC = new TollCollectionBLLC();
dataTable = tollcollectionBLLC.GetTollCollectionDetailsBLLC(187, 1, 1, "10/10/2011");
//put the gridview into the placeholder to get the values of textboxes in gridview
PlaceHolder1.Controls.Add(GridListTollColletion);
foreach (DataColumn col in dataTable.Columns)
{
if (col.ToString() == "TollCollID")
{
BoundField bField = new BoundField();
bField.HeaderText = "TollCollID";
bField.DataField = "TollCollID";
bField.Visible = false;
GridListTollColletion.Columns.Add(bField);
continue;
}
if (col.ToString() == "TollAmtApplicable")
{
BoundField bField = new BoundField();
bField.HeaderText = "TollAmtApplicable";
bField.DataField = "TollAmtApplicable";
bField.Visible = false;
GridListTollColletion.Columns.Add(bField);
continue;
}
if (col.ToString() == "TollCollDesc")
{
BoundField bField = new BoundField();
bField.HeaderText = "Transaction Types";
bField.DataField = "TollCollDesc";
GridListTollColletion.Columns.Add(bField);
continue;
}
if (col.ToString() == "Total")
{
BoundField bField = new BoundField();
bField.HeaderText = "Total";
bField.DataField = "Total";
GridListTollColletion.Columns.Add(bField);
continue;
}
if (col.ToString().Contains("Rate"))
{
BoundField bField = new BoundField();
bField.HeaderText = col.ToString();
bField.DataField = col.ToString();
bField.Visible = false;
GridListTollColletion.Columns.Add(bField);
continue;
}
//Declare the bound field and allocate memory for the bound field.
TemplateField tfield = new TemplateField();
//Initalize the DataField value.
tfield.HeaderTemplate = new GridViewTemplate(ListItemType.Header, col.ColumnName);
tfield.HeaderStyle.HorizontalAlign = HorizontalAlign.Center;
tfield.HeaderStyle.VerticalAlign = VerticalAlign.Middle;
tfield.ItemStyle.HorizontalAlign = HorizontalAlign.Center;
tfield.ItemStyle.VerticalAlign = VerticalAlign.Middle;
//Initialize the HeaderText field value.
tfield.ItemTemplate = new GridViewTemplate(ListItemType.Item, col.ColumnName);
//Add the newly created bound field to the GridView.
GridListTollColletion.Columns.Add(tfield);
}
protected void GridListTollColletion_RowCommand(object sender, GridViewCommandEventArgs e)
{
int tempCarCount = 0;
// here i am getting exception
int.TryParse( ( (TextBox)GridListTollColletion.Rows[Convert.ToInt32(e.CommandArgument)].Cells[Convert.ToInt32(e.CommandArgument)].Controls[3]).Text , out tempCarCount);
}
public class GridViewTemplate : ITemplate
{
//A variable to hold the type of ListItemType.
ListItemType _templateType;
//A variable to hold the column name.
string _columnName;
//Constructor where we define the template type and column name.
public GridViewTemplate(ListItemType type, string colname)
{
//Stores the template type.
_templateType = type;
//Stores the column name.
_columnName = colname;
}
void ITemplate.InstantiateIn(System.Web.UI.Control container)
{
switch (_templateType)
{
case ListItemType.Header:
//Creates a new label control and add it to the container.
Label lbl = new Label(); //Allocates the new label object.
lbl.Text = _columnName; //Assigns the name of the column in the lable.
container.Controls.Add(lbl); //Adds the newly created label control to the container.
break;
case ListItemType.Item:
//Creates a new text box control and add it to the container.
TextBox tb1 = new TextBox(); //Allocates the new text box object.
tb1.Width = 60;
tb1.Height = 22;
tb1.MaxLength = 50;
tb1.ID = "v";
//Creates a column with size 4.
tb1.DataBinding += new EventHandler(tb1_DataBinding); //Attaches the data binding event.
tb1.Columns = 7;
container.Controls.Add(tb1);
//Adds the newly created textbox to the container.
break;
case ListItemType.EditItem:
//As, I am not using any EditItem, I didnot added any code here.
break;
case ListItemType.Footer:
CheckBox chkColumn = new CheckBox();
chkColumn.ID = "Chk" + _columnName;
container.Controls.Add(chkColumn);
break;
}
}
public IOrderedDictionary ExtractValues(Control container)
{
OrderedDictionary dict = new OrderedDictionary();
if (_templateType == ListItemType.Item)
{ string value = ((TextBox)container.FindControl("tb1" + _columnName)).Text;
dict.Add(_columnName, value); }
return dict;
}
void tb1_DataBinding(object sender, EventArgs e)
{
TextBox txtdata = (TextBox)sender;
GridViewRow container = (GridViewRow)txtdata.NamingContainer;
object dataValue = DataBinder.Eval(container.DataItem, _columnName);
if (dataValue != DBNull.Value)
{
txtdata.Text = dataValue.ToString();
}
}
public GridViewTemplate()
{
//
// TODO: Add constructor logic here
//
}
}

Answer 1

The template is applied statically. So, you wont be able to access the control as you are trying to do.
Try using -
var textbox = GridListTollColletion.FindControl(<yourtextbox>);

Answer 2

Is it not convenient if you bind these added controls on GridView.RowDataBound event.
Check this BindData to ITemplate for GridView in code behind
If you are following this MSDN Article How To: Create ASP.NET Web Server Control Templates Dynamically to take idea about this then check this code snippet.
static void Item_DataBinding(object sender, System.EventArgs e)
{
PlaceHolder ph = (PlaceHolder)sender;
RepeaterItem ri = (RepeaterItem)ph.NamingContainer;
Int32 item1Value = (Int32)DataBinder.Eval(ri.DataItem, "CategoryID");
String item2Value = (String)DataBinder.Eval(ri.DataItem, "CategoryName");
((Label)ph.FindControl("item1")).Text = item1Value.ToString();
((Label)ph.FindControl("item2")).Text = item2Value;
}
It have Item_DataBinding a static method. you are setting up this stuff statically, so check this article to improve your code.
In Edit Template i suggest you to use RowBound Event to handle for these template controls.. there you can easily access them.