Vb.net - Add Dynamic User Controls BASED ON ViewState - BUT Before LoadViewState Phase
Jan 27, 2011
Setup:
My page has a drop down whose values are dynamically populated. Based on which item is selected, a number of TextBoxes are dynamically created during runtime.The user then fills in information into the textboxes and clicks a submit button.
Problem:
After postback from the submit button, I need to again dynamically create the TextBoxes during Page_Init (BEFORE LoadViewState) so that after the ViewState loads, my Button_Click event can save/do whatever with the user input. PROBLEM is, I cannot recreate the textboxes based on the selection in the dropdown, because the dropdown hasn't been "selected" yet by LoadViewState.
SO, how can I read from the view state, create my textboxes, then let the viewstate populate the textboxes, and then the Button_Click will use the values??
The one thing I've attempted is to override the LoadViewState function so that I can read from the view state, create the boxes, and then load the viewstate again. This did NOT work, because the debugger never seemed to hit my overridden function.
[code]....
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protected void gvORg_RowCreated(object sender, GridViewRowEventArgs e)
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Apr 24, 2010
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May 28, 2010
I'm new to web dev and c# so please bare with me. I am trying to create a dynamic gridview in a web form for users to to answer questions with (code below).
The dificulty im having is that i am nesting a dropdwonlist in the gridview and want to be able to dynamically set the list values based on parameters (of the row they are on). These values are in the main dataset for the gridview as each row represents a questionid and question text and then a ddl for the criteria...
I just don't know how to set the values for the dropdown all the code so far is below... just need to be able to populate the dropdowns with the relevant values.
I have created a stored proc to return the different criteria based on the questionid and questionGroupid which is the dataset that populates the other fields in the gridview: dbo.usp_QuestionCriteria @QuestionGroupId, @QuestionId
I have added this as a tableadapter called criteriaTableAdapter in a xsd file as well using the wizard... not sure if this is the right option though or just use the same method as i have for the other stored procedure as in the code below:
[CODE
]using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Sql"].ConnectionString);
con.Open();
SqlCommand com = new SqlCommand("usp_QuestionGroupDS", con);
com.CommandType = CommandType.StoredProcedure;
SqlDataAdapter ada = new SqlDataAdapter(com);
DataSet ds = new DataSet();
ada.Fill(ds);
for (int i = 0; i < ds.Tables.Count; i++)
{
if (ds.Tables[i].Rows.Count > 0)
{
GridView gvDynamicQuestion = new GridView();
gvDynamicQuestion.Width = Unit.Pixel(700);
gvDynamicQuestion.BorderWidth = Unit.Pixel(0);
gvDynamicQuestion.Caption = "<div id="nifty" class="QuestionGroup"> <b class="rtop"><b class="r1"></b><b class="r2"></b><b class="r3"></b><b class="r4"></b></b>" + ds.Tables[i].Rows[0]["Category"].ToString() + " Questions<b class="rbottom"><b
class="r4"></b><b class="r3"></b><b class="r2"></b><b class="r1"></b></b></div>";
gvDynamicQuestion.AutoGenerateColumns = false;
gvDynamicQuestion.ShowFooter = true;
TemplateField tf = null;
tf = new TemplateField();
tf.HeaderTemplate = new DynamicGridViewTextTemplate("QuestionId", DataControlRowType.Header);
tf.ItemTemplate = new DynamicGridViewTextTemplate("QuestionId", DataControlRowType.DataRow);
tf.FooterTemplate = new DynamicGridViewTextTemplate(DataControlRowType.Footer, ds.Tables[i].Rows.Count);
gvDynamicQuestion.Columns.Add(tf);
tf = new TemplateField();
tf.HeaderTemplate = new DynamicGridViewTextTemplate("Question", DataControlRowType.Header);
tf.ItemTemplate = new DynamicGridViewTextTemplate("Question", DataControlRowType.DataRow);
gvDynamicQuestion.Columns.Add(tf);
tf = new TemplateField();
tf.HeaderText = "Criteria";
tf.HeaderTemplate = new DynamicGridViewTextTemplate("Criteria", DataControlRowType.Header);
tf.ItemTemplate = new DynamicGridViewDDLTemplate();
gvDynamicQuestion.Columns.Add(tf);
////tf = new TemplateField();
////tf.HeaderText = "Criteria";
////tf.ItemTemplate = new DynamicGridViewDDLTemplate();
////gvDynamicQuestion.Columns.Add(tf);
gvDynamicQuestion.DataSource = ds.Tables[i];
gvDynamicQuestion.DataBind();
phDynamicGridHolder.Controls.Add(gvDynamicQuestion);
}
}
}
protected void DynamicGrid_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Footer)
{
//
}
}
}
public class DynamicGridViewTextTemplate : ITemplate
{
string _ColName;
DataControlRowType _rowType;
int _Count;
public DynamicGridViewTextTemplate(string ColName, DataControlRowType RowType)
{
_ColName = ColName;
_rowType = RowType;
}
public DynamicGridViewTextTemplate(DataControlRowType RowType, int QuestionCount)
{
_rowType = RowType;
_Count = QuestionCount;
}
public void InstantiateIn(System.Web.UI.Control container)
{
switch (_rowType)
{
case DataControlRowType.Header:
Literal lc = new Literal();
lc.Text = "<b>" + _ColName + "</b>";
container.Controls.Add(lc);
break;
case DataControlRowType.DataRow:
Label lbl = new Label();
lbl.DataBinding += new EventHandler(this.lbl_DataBind);
container.Controls.Add(lbl);
break;
case DataControlRowType.Footer:
Literal flc = new Literal();
flc.Text = "<b>Total No of Questions:" + _Count + "</b>";
container.Controls.Add(flc);
break;
default:
break;
}
}
private void lbl_DataBind(Object sender, EventArgs e)
{
Label lbl = (Label)sender;
GridViewRow row = (GridViewRow)lbl.NamingContainer;
lbl.Text =DataBinder.Eval(row.DataItem, _ColName).ToString();
}
}
public class DynamicGridViewDDLTemplate : ITemplate
{
// Implementation of ITemplate
public void InstantiateIn(System.Web.UI.Control container)
{
// Create a DDL
DropDownList ddl = new DropDownList();
//Attach method to delegate
ddl.DataBinding += new System.EventHandler(this.ddl_DataBind);
container.Controls.Add(ddl);
}
//Method that responds to the DataBinding event
private void ddl_DataBind(object sender, System.EventArgs e)
{
//DropDownList ddl = (DropDownList)sender;
//DataGridItem container = (DataGridItem)ddl.NamingContainer;
//ddl.Data.Checked = [Data binding expression];
}
}
[/CODE]
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Feb 3, 2010
can i get a value of a selected radio button in LoadViewState event of the the WebControl and how? All the components are generated in codebehind, so i have those controls:
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ListItem liOne;
ListItem liTwo;
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protected override void LoadViewState(object o)
{
action = rbl.SelectedValue;
action2 = rbl.SelectedItem.Value;
base.LoadViewState(o);
}
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[Code]....
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