how to create textboxes at runtime on button click. As many time as the button is clicked and the value of textbox is to be passed to next page through session.
i have such code so far
int count=0;
protected void btnadd_Click(object sender, EventArgs e)
{
var i = 1;
for (i = 1; i <= count+1; i++)
{
TextBox txt = new TextBox();
form1.Controls.Add(txt);
txt.ID = "r" + count;
txt.Text = txt.ID;
}
}
Here i want to give the ID to all the textbox that will be created at runtime.This code displays textbox only once when the button is clicked. But i want to display textbox everytime when the button is clicked.
If do this
protected void btnadd_Click(object sender, EventArgs e)
{
var i = 1;
for (i = 1; i <= 5; i++)
{
TextBox txt = new TextBox();
form1.Controls.Add(txt);
txt.ID = "r" + count;
txt.Text = txt.ID;
count++;
}
}
there displays 5 textbox with id of textbox like ro,r1,r2,r3,r4.
please help me. I have been working on this for many days.
thanks in advance
I would look at putting an asp:repeater control on the page containing a textbox and changing it's data source (adding more rows to it) for each textbox you want added to the page.
Related
I have the following RowDataBound method for GridView2
protected void GridView2_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
List<TextBox> list = new List<TextBox>();
if (ViewState["Table"] != null)
Assessments = (DataTable)ViewState["Table"];
int count = 1;
foreach (DataRow row in Assessments.Rows)
{
TextBox txt = new TextBox();
txt.ID = "AsTxt";
txt.Text = string.Empty;
txt.TextChanged += OnTextChanged;
e.Row.Cells[count].Controls.Add(txt);
count += 2;
listd.Add((e.Row.DataItem as DataRowView).Row[0].ToString() + "Txt");
}
}
}
And the following event (Button Click) to retrieve whatever written in the text box in the GridView
protected void CalculateBtn_Click(object sender, EventArgs e)
{
GridViewRow rr = GridView2.Rows[0];
TextBox rrrr = (rr.FindControl("AsTxt") as TextBox);
ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('" + rrrr.Text + "')", true);
}
I always get NullReferenceException. That mean the TextBox object (rrrr) is null always. I am sure that the text object sits in GridView2.Rows[0].
Why is this happening?
This is known issue with the Dynamical created controls in asp. So if you want to use the created control on your postback then I suggest that you declare your controls outside the page_int and do your initialization in the init then use them with their name instead of find control.
Look at this blog this might help you
http://techbrij.com/retrieve-value-of-dynamic-controls-in-asp-net
I would like to dynamically create a table with labels and changing the label on the table through button click
I can dynamically provide the table with different labels however i cant change the labels in the table
Here is my code:
.cs
protected ovverride void createchildcontrol()
{
table1.border=1;
}
int counter=1;
for (int i = 1; i <= 8; i++)
{
row = new htmltablerow();
for (int j = 1; j <= 5; j++)
{
label = new label() { id = "label" + counter.tostring() };
cell = new htmltablecell();
cell.innertext = label.text = "label" + counter.tostring();
row.cells.add(cell);
counter++;
}
table1.row.add(row);
}
counter = 1;
cell.controls.add(label);
this.controls.add(table1);
}
my button code
protected void button1_click(object sender, eventargs e)
{
label find = cell.findcontrol("label1") as label;
find.text = "changed";
}
i have a div id="placeholder" runatserver="server" on the other page
I really need to acess the label on my generated HTML table.
You will need to recreate the table on pre_init event. only then it is going to work.
protected override void OnPreInit(EventArgs e)
{
base.OnPreInit(e);
//recreate your table here
}
You can add Controls dynamically controls in the Page Load event too. But in that case , the Control's State cannot persist across PostBacks. So Dynamic added Controls should exist within the Page Control Hierarchy before the View State is loaded. So creating Controls in Init event makes the Control available in the Hierarchy so that it can persist ViewState.
I trying get some programmatically inserted textboxes (inserted into a gridview) to do a textChange partial update. It is sort of working but it does not automatically calls textEntered() method after I typed some text in these textboxes. I got a clue that I might need to use AJAX and things like updatepanels but I just don't fully understand how they will work in the context of what I am trying to do.
protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
if (!e.Row.Cells[4].Text.Equals(" ") && firstTime == false)
{
TextBox tb = new TextBox();
tb.Text = e.Row.Cells[4].Text;
tb.TextChanged += new EventHandler(textEntered);
textBoxArray.Add(tb);
int length = textBoxArray.Count - 1;
tb = (TextBox)textBoxArray[textBoxArray.Count - 1];
e.Row.Cells[4].Text = null;
e.Row.Cells[4].Controls.Add(tb);
Cache["textBoxArray"] = textBoxArray;
} firstTime = false;
}
protected void textEntered(object sender, EventArgs e)
{
lbl_test.Text += "test";//This line is for testing purposes
}
auto postback of textbox is true or false? make it true.
I have gridview built dynamically at run-time bind to datatable, and button to save gridview data placed outside gridview
1- Create GridView
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
CreateGrid();
}
}
void CreateGrid()
{
int nTransID = Convert.ToInt32(Session["trans_id"]);
//
string strSQL = #"EXEC [dbo].[sp_GetTransaction] " + nTransID;
DataTable dtData = clsGlobal.GetDataTable(strSQL);
//
if (ViewState["dtTransDetail"] == null) ViewState.Add("dtTransDetail", dtData);
else ViewState["dtTransDetail"] = dtData;
//
foreach (DataColumn dc in dtData.Columns)
{
if (dc.ColumnName.Contains("!;"))
{
TemplateField tField = new TemplateField();
tField.ItemTemplate = new AddTemplateToGridView(ListItemType.Item, dc.ColumnName);
//\\ --- template contain textbox
tField.HeaderText = dc.ColumnName;
GridView1.Columns.Add(tField);
}
}
}
This is my template class:
public class AddTemplateToGridView : ITemplate
{
ListItemType _type;
string _colName;
public AddTemplateToGridView(ListItemType type, string colname)
{
_type = type;
_colName = colname;
}
void ITemplate.InstantiateIn(System.Web.UI.Control container)
{
switch (_type)
{
case ListItemType.Item:
TextBox text = new TextBox();
text.ID = "txtAmount";
text.DataBinding += new EventHandler(txt_DataBinding);
container.Controls.Add(text);
break;
}
}
void txt_DataBinding(object sender, EventArgs e)
{
TextBox textBox = (TextBox)sender;
GridViewRow container = (GridViewRow)textBox.NamingContainer;
object dataValue = DataBinder.Eval(container.DataItem, _colName);
if (dataValue != DBNull.Value)
{
textBox.Text = dataValue.ToString();
}
}
}
So i have a gridview with textboxe's all open to edit at once
The problem is, when i click on Save button "which is outside gridview" all textboxe's gone
protected void btnSave_Command(object sender, CommandEventArgs e)
{
for (int nRow = 0; nRow < GridView1.Rows.Count; nRow++)
{
for (int nCol = 0; nCol < GridView1.Columns.Count; nCol++)
{
if (GridView1.Rows[nRow].Cells[nCol].Controls.Count == 0) continue;
//\\ --- Controls.Count always = 0
//\\ --- However each cell contain textbox
//\\ --- textbox disappear after save button clicked
TextBox txt = (TextBox)GridView1.Rows[nRow].Cells[nCol].Controls[0];
}
}
}
It looks like you are not creating the GridView after a postback, and the Save button is causing a postback. You need to dynamically create the GridView on each page load. Also, I have found this documentation on the ASP.NET page lifecycle helpful on numerous occasions.
In the documentation, you will see the slightly unintuitive reason why your code isn't working as you would like - btnSave_Command is not run until after a postback and Page_Load.
I want to create dynamic text box when user click on Add more link button.
For this I am using this code. And I have to mention that I am using master page.
protected void lnkAddMore_Click(object sender, EventArgs e)
{
if (Request.Cookies["value"] != null)
{
i = Convert.ToInt32(Request.Cookies["value"].Value) + 1 ;
}
for (int k = 1; k <= i; k++)
{
LiteralControl literal = new LiteralControl();
literal.Text = "<br /><br />";
Label newLabel = new Label();
newLabel.Text = "Choice" + " " + k.ToString();
newLabel.ID = "lblChoice_" + k.ToString();
newLabel.Attributes.Add("runat", "Server");
this.panelLabel.Controls.Add(newLabel);
this.panelLabel.Controls.Add(literal);
LiteralControl literal1 = new LiteralControl();
literal1.Text = "<br /><br />";
TextBox nexText = new TextBox();
nexText.ID = "txtChoice_" + k.ToString();
nexText.Attributes.Add("TextMode", "MultiLine");
nexText.Attributes.Add("runat", "Server");
panelTextbox.Controls.Add(nexText);
this.panelTextbox.Controls.Add(literal1);
Response.Cookies["value"].Value = i.ToString();
Session["Panel"] = panelTextbox;
}
}
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (Session["Panel"] != null)
{
ContentPlaceHolder content=new ContentPlaceHolder();
content.Controls.Add(Session["Panel"] as Panel);
}
}
}
Now I am facing trouble how to retrieve the data of the these text boxes after the clicking on the submit button so that I can store the values of there text boxes to database.
What will be code written for the click event of btnSave
protected void btnSave_Click(object sender, EventArgs e)
{
if (Session["Panel"] != null)
{
ContentPlaceHolder content_new = new ContentPlaceHolder();
for (int i = 1; i <= count; i++)
{
strControlName = "txtChoice_" + i.ToString();
TextBox objTextBox = (TextBox)content_new.FindControl(strControlName);
strTextBoxValues[i] = objTextBox.Text;
string str3 = strTextBoxValues[2];
}
}
}
This code is showing error for objTextBox. The error is NullReferenceException.
How to write stored procedure for saving data of above code?
The main problem is handling the parameter declaration, how to declare dynamic parameter for passing values so that value is saved for dynamic textbox?
Thanks.
I have already answered it here.
Lost dynamically created text box values
You can try this.
private string GetValue(string ControlID)
{
string[] keys = Request.Form.AllKeys;
string value = string.Empty;
foreach (string key in keys)
{
if (key.IndexOf(ControlID) >= 0)
{
value = Request.Form[key].ToString();
break;
}
}
return value;
}
Then to get the value
string txtChoice1value = GetValue("txtChoice1");
First of all when you dynamically create a control it doesn't need to be set "runat = sever".
Problem is in this line `ContentPlaceHolder content_new = new ContentPlaceHolder();` you make a new ContentPlaceHolder, this mean it doesn't have any control to be found.
Check this page. How To Create TextBox Control Dynamically at Runtime
You need to find the reference of your already created ContentPlaceHolder like-
ContentPlaceHolder cnt =(ContentPlaceHolder)this.Master.FindControl("ContentPlaceHolder1");
and then add the dynamically created Control in that ContentPlaceHolder as-
cnt.Controls.Add(Session["Panel"] as Panel);
Why you creating a new ContentPlaceHolder each time even when you have mentioned that you are using masterPage, so there must exists a ContentPlaceHolder..
Controls wont persist on postback have a look at http://www.denisbauer.com/ASPNETControls/DynamicControlsPlaceholder.aspx