Dynamically Reference An Object Property Using A String?
Jan 21, 2011
I'm trying to reference a public property from a string. How can this be done in vb.net? I have the text value of "FirstName" stored in strucParam(i).TxtPropertyName.
This is what I'm currently doing:
Dim tmpValue As String
Dim ucAppName As UserControl_appName = CType(Parent.FindControl(strucParam(i).ParentFindControl), UserControl_appName)
tmpValue = ucAppName.FirstName.Text
How can I use the value in strucParam(i).TxtPropertyName so that I can remove ".FirstName" from my code?
<%@ Import Namespace="System.Data.SqlClient" %> <script runat="server" > Dim connStr As String = ConfigurationManager.ConnectionStrings("cc").ConnectionString.ToString dim db As New Data.SqlClient.SqlConnection(connStr)
why this error
Object reference not set to an instance of an object.
on VWD 2005 this code works fine, but on 2008 it says I haven't created an instance of the object. I want to convert the object connString (a connection string) into a string.
'This acceses the virtual directory web.config file for connection strings 'We have to convert the object to a connection string Dim rootWebConfig As System.Configuration.Configuration rootWebConfig = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("/VirtualDirec") Dim connString As System.Configuration.ConnectionStringSettings connString = rootWebConfig.ConnectionStrings.ConnectionStrings("ConnectString1") Dim strConnString As String = connString.ToString().......
I'm using jQuery and setInterval method in my asp.net web application.
I call the webservice every 5 seconds in order to check for DB changes. When i see a change, i want to change the photo of the linkButton that located on the master page, but i can to that due to static constrains.
An object reference is required for the non-static field, method, or property 'System.Web.UI.Page.Master.get'
my c# code is:
[WebMethod()] public static bool checkDBChange(string userId) { DBConnection dbConnection = new DBConnection(); if (dbConnection.isChanged(userId)) { ((Site1)Master).SetImageUrl = "~/Icons/a.ico"; } return false; }
The SetImageUrl is a setter in my master page that sets the new url to the linkButton. How I can implement it?
I am getting a CS0120 error when trying turn a button visible after checking some variables. In plain english, If AmmohelpSession.UserActions contains AmmohelpEnums.UserAction.ArticleEdit then turn the Edit button visible. Here is my comparison:
[Code]....
In the code behind for AmmohelpSession, a public class AmmohelpSession which contains a private variable: private HashSet<UserAction> _userActions; has been stated. In that same file, there is a public function for the UserActions that does a get or set method.In the code behind for AmmohelpEnums, we are setting byte variables to specific actions. Mine would be something like:
in my default.aspx page i have a dropdown List and a textbox with a submit button below that there are 2 listbox... and the dropdown list holds the names of the listbox
my logic here is to select an item from the dropdown list and put some text in the text box and submit the form which will add an item to the listbox selected.. but when i do this i get an error saying Object reference not set to an instance of an object. i tried to figure out the problem and found that when i remove the reference to the Site Master Page it works fine and when i undo and apply my reference back to the Site Master Page i get the same error.
http://www.codedigest.com/Articles/ASPNET/232_Picasa_Style_Photo_Album_Using_ListView_Control_in_ASPNet_35.aspx originally written in C#. I'm using VB.Net (Asp.net 4.0) and I'm getting the following errors for Albums.aspx, Photos.aspx, PhotoViewer.aspx pages. I have attached a screenshot of my two tables.Input string was not in a correct format.
Description:An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.FormatException: Input string was not in a correct format.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.FormatException: Input string was not in a correct format.Source Error: [Code]....
Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.Source Error,[Code]....
I am using grid view as mentioned below, it is giving me error "object reference not set", but if comment allowpaging and pagesize lines, it works. let me know whats wrong I am doing?
Traditionally with an Object Data Source, the wired up class will have its public properties available for binding (i.e. Gridview columns, etc.) which works well. But what if one of my wired up business objects has a property that is an object itself; can I drill down to a property on that object property and still use it?
So in additiona to the traditional:MyBusniessObject.OrderID...I want to use:MyBusniessObject.Customer.NameID Your 1st response might be to just wire up the 'Customer' class, but I need properties both on 'MyBusinessObject'and 'Customer'. I do not think this can be done, as the ODS will not display properties on an object instance property. I have tried manually typing in the drilled down value as well, but that wasn't a success either.
I'm using Entity Framework. The following code throws a runtime error "System.NullReferenceException: Object reference not set to an instance of an object." The line before the error, it looks like newControl is in fact instantiated.
My model has a Control entity and a ControlType entity. Control includes the Navigation Property "ControlType." I'm trying to set ControlType.Type = 2.
I am working on converting a project from C# to VB and am facing this weird issue. 1 page cannot compile and I get the reference error, but the weird thing is that the compiler shows the error as coming from ASP.NET generated code. Visual Studio shows me that error is coming from my ASPX page. I cannot seem to figure out why or where this error is occuring. Also if I take the inherits attribute out I don't get the compilation error. The code in aspx page is below:
http://www.somepage.com/main.aspx. In this page, when I click on a link it takes me to a page http://www.somepage.com/cental.aspx?cid=200. So in the cental.aspx.cs page I did the following in the page load:
if(request.querystring["comp"].tostring() != null) { //do some thing [code].....
So I got an error like: object reference not set to an instance of reference.My problem is, I am using the same page. So when I go from some page, I will have "comp". but other times not. So when there is no "comp", how do I handle it in request.querystring?
In the VS2005 environment, when I test my session to make sure the page redirects to the main page (itself) if the session is null, it works. There is no error.
The function I use for this is:
[code]....
However, when it is in the production environment in IIS 6.0, when the session has timed out, and I then do a postback by doing some slider control, I see the page reload but immediately thereafter, it throws a Server Error exception of : Object reference not set to an instance of object.
however, why is it that the Slider1_TextChanged event fired even even after during page_load, the page was told to do a response.direct ?? shouldn't the entire page have gone through a full-page refresh life cycle ? why did it continue on to attempt to raise the Slider1_TextChanged event?
this works fine on my local site but as soon as i upload the site to my live server i get stem.NullReferenceException: Object reference not set to an instance of an object
on the first line of this:
if (!Page.User.Identity.IsAuthenticated) { pnlSignIn.Visible = true; pnlSignOut.Visible = false; }
can you please help me to brainstorm the possible causes of this error. I've got a paged repeater with localisation bound programitcally to an sqldatasource using a stored proc. I can post code if needs be but it's rather long. I'm looking for typical causes of this error + will make note for future reference!
erver Error in '/WebSite4' Application.
Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
[Code]....
Line 233:Line 234: Repeater1.DataSource = PagedResultsLine 235: Repeater1.DataBind()Line 236: doPaging()Line 237: End Sub
I'm new to programming in ASP.NET, but I'm making my way through Wrox's Beginning ASP.NET 3.5 in C# and VB.NET.
I'm at a section where I'm creating a BasePage. I successfully created a BasePage by creating a new class file in my App_Code folder called BasePage.cs with the following code:
[Code]....
If I run that code everything works out fine. The page loads and all is well. But, if I try to do the same thing to a page that uses my MasterPage.master file, I get the following error:
Object reference not set to an instance of an object.
Description:
An unhandled exception occurred during the execution of the current web request. review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Why is that? In the example code from the book (that also uses a MasterPage.master file), everything excutes and runs just fine. But in my test, I get the above error. I've tried comparing my pages to the books included source pages, but I can't find any differences.
I have a website written in C# that was running fine on one server. We moved it to another server and have a couple issues. I am mainly a VB.NET coder but can do a few things in C#. This is not a project - it is a website and can open it in VS2008 no problem. This is an admin site for the whole website where the user can add customer comments, etc. When logging in, it works fine. I can go to one of the admin pages after logging in and works. If I go to two other different pages, I get this error:
Object reference not set to an instance of an object.
[Code]....
It turns out this is in the main.master page and it is used by the other pages that load fine. The ApplicationTitle variable is set right in the web.config file and like I said, it shows on the other pages.
My question is why would this code work fine for some pages and not two others? All of these admin pages are under a folder called Admin and the web.config file is in the root folder of the website. Its almost like these two pages cannot see the web.config file in the root folder? Why would that be if thats the case?
We have an applicaiton that was converted to the new framework using the wizard in Visual Studio 2008. When we install the applicaiton in production and change the iis settings to use the 2.0 framework we start to see these errors in the event viewer on the web servers. We are using SQL Server Session State and have 3 web servers in a load balancer. Object reference not set to an instance of an object.</Message><StackTrace> at System.Web.SessionState.SessionStateModule.PollLockedSessionCallback...
I have a webservice, it has few webmethods. when i create a client proxy and invoke the methods to check its response, i am getting this error. Can someone tell me what things can i check to know the cause of this? The error is not saying much hence blocked on this.
