I got problem finding the Control ID in my ASP.NET page.
When I try to refer that ID, it always give me:
I am trying to refer this:
[Code]....
I pass this id from here:
[Code]....
This is my code behind which is driving me crazy :(
[Code]....
When I use label to display the STRING INTIME, IT GIVES ME "textboxCashier1In"
BUT WHEN I DO THIS:
[Code]....
Object reference not set to an instance of an object. when I try to access these dynamically created controls using FindControl.
I have a dynamically created control within a table cell. The table itself is contained within a page that has a master page. I've tried so many different ways to access this control.
Below is the latest iteration
AttrTable is the asp table, and row.Attr_Type is the name I've given to the control (it iterates through a datatable to set the names for the control)
tmpVal = CType(AttrTable.FindControl("TD_" & row.Attr_Type).FindControl(row.Attr_Type), DropDownList).Text
Below are various ways I've tried to access the control:
Dim form As Control = Page.Master.FindControl("form1")
Dim content1 = form.FindControl("ContentPlaceHolder1")
[Code]....
I add a select control to a ASPX page like below:
hgc = new HtmlGenericControl();
hgc.InnerHtml = @"<select runat='server' id='my_selectlist'>
<option value='volvo'>Volvo</option>
<option value='saab'>Saab</option>
<option value='mercedes'>Mercedes</option>
<option value='audi'>Audi</option>
</select>";
Then in a Button click event, I use the code below, try to get the value selected
HtmlSelect s = (HtmlSelect)hgc.FindControl("my_selectlist");
label.Text = s.Value;
I get a error:"Object reference not set to an instance of an object."Does anyone try it before?
I have a PlaceHolder control inside of a ListView that I am using to render controls from my code behind. The code below adds the controls:
TextBox tb = new TextBox();
tb.Text = quest.Value;
tb.ID = quest.ShortName.Replace(" ", "");
((PlaceHolder)e.Item.FindControl("ph_QuestionInput")).Controls.Add(tb);
I am using the following code to retrieve the values that have been entered into the TextBox:
foreach (ListViewDataItem di in lv_Questions.Items)
{
int QuestionId = Convert.ToInt32(((HiddenField)di.FindControl("hf_QuestionId")).Value);
Question quest = dc.Questions.Single(q => q.QuestionId == QuestionId);
TextBox tb = ((TextBox)di.FindControl(quest.ShortName.Replace(" ","")));
//tb is always null!
}
But it never finds the control. I've looked at the source code for the page and the control i want has the id:
ctl00_cphContentMiddle_lv_Questions_ctrl0_Numberofacres
For some reason when I look at the controls in the ListViewDataItem it has the ClientID:
ctl00_cphContentMiddle_lv_Questions_ctrl0_ctl00
Why would it be changing Numberofacres to ctl00? Is there any way to work around this?
UPDATE:
Just to clarify, I am databinding my ListView in the Page_Init event. I then create the controls in the ItemBound event for my ListView. But based on what @Womp and MSDN are saying the controls won't actually be created until after the Load event (which is after the Page_Init event) and therefore are not in ViewState? Does this sound correct?
If so am I just SOL when it comes to retrieving the values in my dynamic controls from my OnClick event?
UPDATE 2:
So i changed the code i had in my Page_Init event from:
protected void Page_Init(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
//databind lv_Questions
}
}
to:
protected void Page_Init(object sender, EventArgs e)
{
//databind lv_Questions
}
And it fixed my problem. Still a little confused as to why I want to databind regardless of whether it's a postback or not but the issue is resolved.
So all I want to do is simply find a user control I load based on a drop down selection. I have the user control added but now I'm trying to find the control so I can access a couple properties off of it and I can't find the control for the life of me. I'm actually doing all of this in the master page and there is no code in the default.aspx page itself.
MasterPage.aspx
[Code]....
MasterPage.cs
protected void goToSelectedPage(object sender, System.EventArgs e)
{
temp1 ct = this.Page.Master.LoadControl("temp1.ascx") as temp1;
ct.ID = "TestMe";
this.UpdatePanel1.ContentTemplateContainer.Controls.Add(ct);
}
//This is where I CANNOT SEEM TO FIND THE CONTROL ////////////////////////////////////////
protected void lnkSave_Click(object sender, System.EventArgs e)
{
UpdatePanel teest = this.FindControl("UpdatePanel1") as UpdatePanel;
Control test2 = teest.ContentTemplateContainer.FindControl("ctl09") as Control;
temp1 test3 = test2.FindControl("TestMe") as temp1;
string maybe = test3.Col1TopTitle;
}
Here I don't understand what it's telling me. for "par" I get "ctl09" and I have no idea how I am supposed to find this control. temp1.ascx.cs
protected void Page_Load(object sender, EventArgs e)
{
string ppp = this.ID;
string par = this.Parent.ID;
}
I have an asp:table control that I construct dynamically. I place a few textboxes in it within a for loop and assign their IDs in code. I'll include an abbreviated code fragment showing how I'm doing this:
[Code]....
The page then displays correctly and the ID is set correctly when I view the source, but when I try to access the textbox later when the form is submitted the call to FindControl(idStr) returns null no matter what I do.
I'm sure I'm doing something wrong here, but I cannot figure it out.
This is in my aspx page:
[code]....
And this is in my aspx.vb page:
[code]....
How do we code "findcontrol" with a third party control? I tried "TextBox" for Namespace="FreeTextBoxControls" Assembly="FreeTextBox" and it threw an error:
Object reference not set to an instance of an object.
Here is the offending line:
Dim Body As String = Convert.ToString(CType(lsvBlocks.InsertItem.FindControl("FreeTextBox"), TextBox).Text)
I have a form with a basic FormView control. The FormView is set to Edit mode by default with only two textboxes and one button. I am populating the FormView using a Datatable from the code behind generated from a SQL Stored Procedure.
The data fills the FormView just fine. I am attempting to update the data using a SQL Stored Procedure by getting the values from the textboxes in the FormView on button click Everything seems to work and I recieve no errors, however the values I type into the textboxes is not passed to the stored procedure so eventhough there are no errors the data is not updated.
I know that the issue is not my stored procedure becasue if I use static values for the parameters in the code behind, the values are updated by the stored procedure.
I placed two plain textboxes and a button on the ASPX form and create a button click event for that button using the same code I use for the butten click event in the formview. When I add values to the non-databound textboxes, the data is updated correctly.
The question is, why can I not get the updated/changed values from textboxes in the FormView control?
Here is my ASPX code:
[Code]....
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In the gridview we are using edit button. Once the edit button click Controls in the edit template will display in the same row with update button. That row has two dropdownlist control.
Process flow:
controls:d1 and d2
d1 is using sqldatasource for item display : working fine.
d2 is using codebehind code to load the item based on the selected value in the d1 : Not working
How to findthe control in the edit template to display item value for d2.
I want to change the text of the user name text box which is inside a log in view on selected index chaged event of a drop down list.
this is my code:
[Code]....
but both ddl and tb are null
Anyone knows how can I find the controls in code behind?
How to use Control Parameter with SQLDataSource When FindControl is required?
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I have a situation where I need to dynamically disable certain controls. I will not be knowing the type of control. I tried to use FindControl(""), but this does not have the "Enabled" property, it only has "Visible" property.
Kindly let me know how this can be done.
I have a literal8 inside panel1 and panel1 inside datalist1 ..
i wanna insert the value in literal1 on page load event using query string ...
ERROR on Page Load : Object reference is not set to the instance of an object
how to make this code workin ?
Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit
Dim lit8 As Literal = DirectCast(DataList1.FindControl("Literal8"), Literal)
lit8.Text = Me.Request.QueryString("room")
End Sub
How can I access to the CancelPushButton ?
This doesn't work ! it returns always null !!
var cancelButton = ChangeUserPassword.FindControl("CancelPushButton");
[Code]....
I use the following method to find a control on an asp.net page recursively:
/// <summary>
/// Searches recursively for a server control with the specified id parameter.
/// </summary>[code]...
I hit a problem because it was returning the wrong control. I tracked the problem down to the standard FindControl method, and fixed it by checking that the id of the control returned did actually match the one requested like this:
foundControl = start.FindControl(id);
if (foundControl != null && foundControl.ID == id)
return foundControl;
My question is why does start.FindControl(id) ever return a control that does not match the id requested?
Consider the following code, adding 2 textboxes with the same ID (oops):
protected void Page_Load(object sender, EventArgs e)
{
string TextBoxName = "TextBox1";
Panel p = new Panel();
TextBox t = new TextBox();
t.ID = TextBoxName;
p.Controls.Add(t);
if (p.FindControl(TextBoxName) == null) // <-------*******
{
TextBox t2 = new TextBox();
t2.ID = TextBoxName;
p.Controls.Add(t2);
}
Page.Form.Controls.Add(p);
}
The code is designed to stop adding the same ID twice. However, the Panel.FindControl() method is not finding a control that was added in the previous line of code.
Am I using this in the wrong way?
I mean - sure - I could manually iterate through the controls in the next level, like:
string TextBoxName = "TextBox1";
Panel p = new Panel();
TextBox t = new TextBox();
t.ID = TextBoxName;
p.Controls.Add(t);
TextBox t2 = new TextBox();
t2.ID = TextBoxName;
bool duplicateFound = false;
foreach( Control c in p.Controls )
{
if(c.ID == TextBoxName)
{
duplicateFound = true;
break;
}
}
if( duplicateFound )
{
t2.ID = TextBoxName + "__0";
p.Controls.Add(t2);
}
But I don't understand why this isn't working, whereas Placeholder controls and UserControls work fine.
The reason I am using Panels is for CSS styling. body > div > input - but still - it isn't working.
I'm trying to find a TextBox in the code-behind page, it's inside a nested master page and also then inside another control container (it's inside ctrlCheckoutShippingAddress also) .
I've tried this:
[Code]....
[Code]....
how to find Textbox Control inside DetailsView Control Using Javascript, I tried below but gives an error OBject reference not found
document.getElementById('<%=DetailsView1.FindControl("TextBox1").ClientID%>');
<asp:Content ID="Content3" runat="server" contentplaceholderid="ContentPlaceHolder3">
<asp:LoginView ID="LoginView1" runat="server">
<AnonymousTemplate>
<asp:Login ID="Login1" runat="server" BackColor="#FFFBD6" BorderColor="#FFDFAD"
BorderPadding="4" BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana"
Font-Size="0.8em" ForeColor="#333333" onauthenticate="Login1_Authenticate1"
[code].....
i have used an login control for the users who have not logged in and defined login verification method on the click event of the button but while excuting i do get an error
Error 1 The name 'Login1' does not exist in the current context
i have a gridview control i added checkbox contrl dynamically but i am not getiing the reference of checkbox in button clilck event here is my code Gridvew
[Code]....
.vb code
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I have on dropdown that show hide user control. In the user control i have Ok and Cancel button.
When the dropdown change i want to apply ValidationGroup on the Ok button that is inside UserControl.
I am developing a asp database that is linked with SQL Database. When I am tryind to Find Control (GridView2) inside of another control (Panel2) that sits in Item Template for DetailsView, I got an error message:
Object reference not set to an instance of an object.
<asp:DetailsView ID="DetailsView1" HeaderText="Details" HeaderStyle-CssClass="labelheadRight" runat="server" AutoGenerateRows="False" DataKeyNames="pk_BackupDriveSerial"
DataSourceID="SqlDataSource1" GridLines="None"
CssClass="Detailsview" AllowPaging="True"
OnDataBinding="DetailsView1_OnDataBind"
OnItemInserted="DetailsView1_OnInsert"
OnItemDeleted="DetailsView1_OnDelete"
>
<Fields>
<asp:BoundField DataField="pk_BackupDriveSerial" ControlStyle-CssClass="dropdownsize"
HeaderText="Serial No" ReadOnly="True"
SortExpression="pk_BackupDriveSerial" >
<ControlStyle CssClass="dropdownsize"></ControlStyle>
</asp:BoundField>
<asp:BoundField DataField="BackupDriveMake" HeaderText="Make" ControlStyle-CssClass="dropdownsize"
SortExpression="BackupDriveMake" >
<ControlStyle CssClass="dropdownsize"></ControlStyle>
</asp:BoundField>
<asp:BoundField DataField="BackupDriveModel" HeaderText="Model" ControlStyle-CssClass="dropdownsize"
SortExpression="BackupDriveModel" >
<ControlStyle CssClass="dropdownsize"></ControlStyle>
</asp:BoundField>
<asp:TemplateField HeaderText="Type" SortExpression="fkid_BackupDriveTypes" ControlStyle-CssClass="dropdownsize"
Visible="False">
<EditItemTemplate>
<asp:Label ID="Label6" runat="server" Text='<%# Bind("BackupDriveMake") %>' Width="145px"></asp:Label>
<br />
<asp:TextBox CssClass="dropdownsize" AutoPostBack="true" ID="DropDownList5" runat="server" Text='<%# Bind("BackupDriveModel") %>' ></asp:TextBox>
<br />
<asp:Panel ID="Panel2" runat="server" CssClass="dropdownpanel" >
<asp:GridView CssClass="dropdowngrid" ID="GridView2" runat="server" AutoGenerateColumns="False"
CellPadding="4" DataKeyNames="pkid_BackupDriveTypes" SelectedValue='<%# Bind("fkid_BackupDriveTypes") %>'
DataSourceID="SqlDataSource3" ForeColor="#333333" GridLines="None" OnSelectedIndexChanged="GridView2_OnChange">
<RowStyle BackColor="#EFF3FB" />
<Columns>
<asp:BoundField DataField="pkid_BackupDriveTypes"
HeaderText="pkid_BackupDriveTypes" InsertVisible="False" ReadOnly="True"
SortExpression="pkid_BackupDriveTypes" Visible="False" />
<asp:BoundField DataField="BackupDriveMake" HeaderText="Make"
SortExpression="Make" />
<asp:BoundField DataField="BackupDriveModel" HeaderText="Model"
SortExpression="Model" />
<asp:CommandField ShowSelectButton="True" />
</Columns>
<FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
<HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
<EditRowStyle BackColor="#2461BF" />
<AlternatingRowStyle BackColor="White" />
</asp:GridView>
</asp:Panel>
<asp:DropDownExtender ID="DropDownExtender2" runat="server" DropDownControlID="Panel2" TargetControlID="DropDownList5">
</asp:DropDownExtender>
</EditItemTemplate>
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I also tried
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i have problem in using ajax control , till morning it everything was file , now when i add any new ajax control it shows the error Control canot be created because visual studio cannot find the control's type in the control assembly then if i press OK it says The operation could not be completed . invalid FORMATETC structure
View 5 Repliesi have AccordianPane containing several Panes
each pane containing a table with multiple Textbxoes,lables
at runtime i want to find controls by its id's
for this i tried using
Control ctrl = this.FindControl(id);
but its not working as all the control id's are getting modified with "ctrl" prefix textbox with id "txtName2" modified to "ctrl9_txtName2"
how can i get the exact control by the id's like