Web Forms :: Predicting Assigned Id's Or A Better Way To Get The Object?
Aug 26, 2010
I'm messing with setting some values in javascript and I assumed my input box would have the same id as my original asp.net textbox that created it... it doesn't.
Asp.net added gridview1_ctl02_ to the beginning of all my id's. I see that 'gridview1' is coming from my gridview ID but what is ctl02 and can I assume that will always be what's added or is there a better way of getting this object sent to my javascript?
I am declaring a list in my class, populating the list in page load and using the list in various methods in this class. But, I get this error at every instance where I use this list in the methods. Error: System.NullReferenceException: Object reference not set to an instance of an object.
----> I have datatable which is passing to another page in session variable. ----> Now on another page i take the session variable into datatable.
datatable ds_table = new datatable(); ds_table = (datatable)session["table_value"];
----> so problem, is that , when i filtering some rows from ds_table . that taking effect in the session variable. if some rows deleted from ds_table. then it is also deleted from session variable.
----> so, anyone tell me why is this going to happene?
The line "Return strLoc" below shows the green line underneath strLoc with the message "Variable 'strLoc' used before it has been assigned a value." In fact, it returns the value just fine to the calling module, so I'm wondering why it's giving this message and how to prevent it.
I am stuck with a problem. I have a product page which consits of 2 content place holders. in one of them there is gridview bounded with produtcs and in the other there will be dynamically generated checkboxes used to filter the grid view. upon clicking a checkbox the gridview is filtered showing the products that match the checkbox criteria AND the checkboxes must also be filtered so that checkboxes which were available for previous products should be deleted.
I am loading the checkboxes in the page load. When I enable viewstate for the checkboxes I get the following error:
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
when I disable the viewstate of the checkboxes I get the following error:
An error has occurred because a control with id 'ctl00$refineProducts$ctl04' could not be located or a different control is assigned to the same ID after postback. If the ID is not assigned, explicitly set the ID property of controls that raise postback events to avoid this error.
I have a publice variable to be used in the same webpage. when the user click on button 1, it does some process and assign a value to my public variable. After that, the user can click on button 2 which needs the public variable value to function. However I see the value of the public variable is 0 when I click on button 2.
xamount is receiving this message on the last line. The session is being set in the previous page. Is there a way to resolve the message or should I just use a previous page postback
I am having an odd situation with a dynamic image button. This button is part of a dynamically built asp table which lives in a repeater. Not sure if that complicates things or not, but here's the issue. Since the buttons are dynamically built, if I let asp.net handle the ids I get a crash on postback. Not entirely sure why, but If I set the id in code, I don't get the duplicate id error but I don't get the event fired either. Here is the code building the button:
[Code]....
With this code the IB_Validate_Click never fires. If I comment out the IB_Validate.ID line, the event fires. But, as mentioned above, I have an id clash on a postback. Any ideas why the IB_Validate_Click doesn't fire on this button if the id is set?
When I run this the error is 'Invalid column name 'assigned'.'Yet if I load up Microsoft sql server management studio and run the query against the same db:
[Code]....
I get the data I was expecting and the column does exist?
I have some dropdown list boxes that I need to fill with data from a database but I also need the first option to be "Show All"... So I need to combine using a datasource and manually adding an item to the top of the list. I have tried two different ways with no luck:
1. with the appendDataboundItems = true, on aspx page, and below code in codebehind:
I've got a detailsview control on a page. The table that it interacts with has a DateTime column in it. This column is nullable, and a lot of the records have null for that value. In the EditItemTemplate I've got a calendar control. When I try to put the DetailsView into edit mode, I get the following error message:
System.InvalidCastException was unhandled by user code Message=Specified cast is not valid. Source=App_Web_srpmlyjd StackTrace: at ASP.entries_aspx.__DataBinding__control44(Object sender, EventArgs e) in c:inetpubwwwrootMediaLibraryEntries.aspx:line 103 at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) at System.Web.UI.Control.DataBindChildren()
I am convinced that the problem is the null values in the DateTime column of the table. I've done some web searches on this, and some have suggested placing some dummy values into that column, but that seems more like a kludge, rather than a solution. How do I keep nulls in the table, and yet not have that preceeding error come up when a user tries to edit the selected record?
I have a listivew that is assigned a datasource in the code behind based on query string options. From what i have found out, once there is no datasource assigned in listview html then the sort feature stops working automatically and you must put the code in the _Sorting event. I cannot find a good example of this logic.
I assigned a int value to to one of the cells in an array and then output that value to a label. The label correctly displays that value however when I try to get that value later in a different method the cell returns a 0. I think that the problem is that I shouldn't of made the array on the outside of a method; I checked the code that deals with the array about 3 times and it all seems fine. how I should create, get, and set this array. I was setting the value of the cell like this
arrayForXps[0,1] =Convert.ToInt32(ddl_att_desLvl.SelectedValue); //This value is never zero.
I was getting the value like this Label.Text = Convert.ToString(arrayForXps[0,1]);
I am trying to access a user's login credentials to find out if they are an admin user or not. This way I can assign session variables to them and show certain aspects of the web page that other users won't see. I unfortunately keep getting this error when trying to dim a variable to assign the values too.
Variable Nuid is used before being assigned a value. Variable AdminUser is used before being assigned a value.
Code: Protected Sub checkAdmin_Click(sender As Object, e As EventArgs) Handles checkAdmin.Click Dim strNuid As String = Request.Form("Nuid") Dim cnString As String = ConfigurationManager.ConnectionStrings("snfTimeSystemConnectionString").ToString() Try Using cn As SqlConnection = New SqlConnection() cn.ConnectionString = cnString
I was working on my homework, making a website obiously, but I have a small problem with the griedview. I wanted to add a button on the end of the row, but I receive some error notifications and warnings too...
SeverityCodeDescriptionProjectFileLineSuppression State ErrorBC30518Overload resolution failed because no accessible 'Add' can be called with these arguments: 'Public Overloads Sub Add(column As DataColumn)': Value of type 'ButtonField' cannot be converted to 'DataColumn'. 'Public Overloads Function Add(columnName As String) As DataColumn': Value of type 'ButtonField' cannot be converted to 'String'.GIPH:GIPSearch.aspx.vb31Active
I'm pretty new to silverlight and asp.net but I have a strong background in c#. I am currently developing a c# asp.net application with silverlight elements. I was wondering if it was possible to have a user say click on an image that has a certain value associated with it and have that value access from a c# variable held outside the silverlight application.
On Default.aspx.vb page under on_load sub I'm setting a value on Session() but, if I try to access the same value on Default.aspx, it shows as empty. Here is the code:
I'm fairly new to ASP.net development as may have been noticed by some of my other posts and so here goes another one.I have a web page in which I allow users to enter data that will be used to populate a database and then graph data based on the information that was saved in the database. I have 10 sets of criteria that the user can enter and as they enter values for each individual set, I make sure all the parameters are filled in and set a variable called blnParm1, blnParm2, blnParm3, etc. Anyway, as each DropDownList box fires off an event the values of my blnParm variables is reset because each time the event is fired the page is PostBack therefore my variables are redeclared. I know the page is being PostBack because each of the DropDownList boxes have AutoPostBack set to true. I had to do this so that I could get the OnSelectedIndexChanged event to fire for each of the DropDownList boxes. So, how do I preserve my variables through this PostBack or how do I get the events to trigger without calling AutoPostBack?
Some more info, my variables are declared globally in my aspx.cs file as private bool. The code is working like it should as far as populating drop downs dynamically based on other data input by the user, the controls all have their values preserved as the page is PostBack.
I am getting an exception on a linq to sql query:The null value cannot be assigned to a member with type System.DateTime which is a non-nullable value type.
What I don't quite understand is how the value for ObjectRecordID gets assigned. I understand by looking at the code that AlerId is getting assigned to ObjectRecordID but how is ((Alert)Container.DataItem).AlertId grabbing its value?
I m developing a Web Based Inventory System Using ASP.NET which have a menu containing 16 options overall. I have created a menu using <ul> <li> tags. When I open my project in browser, it shows all the 16 options even i logged in with Administrator or Purchaser or Seller or Accountant etc.
I have a form to assign the Form Access Rights to every user. For example Administrator can use all the options but Seller can use only 3 options (Sales / Sales Return / Today's Sale Report). Purchaser can use 3 options (Purchase / Purchase Returns / Today's Purchase Report) Accountant can use 2 options (Payment / Receipts) etc.How can i show the menus to the users according to the rights assigned.
I got the following error when i tried to insert a new record after the run my project, so what does this error indicates?
"{"Cannot insert explicit value for identity column in table 'Articles' when IDENTITY_INSERT is set to OFF."} System.Exception {System.Data.SqlClient.SqlException}
