Forms Data Controls :: Programmatically Selecting An Object To Be Sent To Browser?
Oct 27, 2010
I have 2 gridviews, and 2 sqldatasources in my web form. Depending of the value of some variable one of the gridviews is visible, and the other one no.
Everything works fine, but my server send usless information about hidden gridview to the client, what in fact slower the speed of displaying a web page in the client browser.
Is there any method which tells asp.net not to send this object to the client during one particular page generation?
Given a gridview has 10 pages comprising of 10 records/page, how do I programmtically select a particular page in the code behind ? For instance, I'd like to set page 5 as the current page of the gridview during databind. I do not have any codes at this stage but this is what I'd like to achieve.
I have a drop down box with values that shows on loadUnited States Canada Now I have a function that is checking the users value from the database which is fired on a button click. What I plan on doing is comparing the string like if United States(db value) == United States (dropdown value) then go ahead and select United States in the drop down. When I do this I am getting the right value selected but it is making all the values the same for all records.
I used bind all GridViews, DetailViews etc. on my page using an ObjectDataSource (unless it wasn't possible to do so). Recently, I've started binding all my contols programatically. I find this a lot cleaner and easier, though some may disagree. Binding with a ObjectDataSource obviously has it advantages and disadvantages, as does doing it programatically.Say I bind a GridView programatically (e.g. GridView1.DataSource = SomeList), when I change page on the GridView, I have to also code this. Each time the page changes I have to call GridView1.DataSource = SomeList again. Obviously with a ObjectDataSource I don't need to do this. I normally stick my SomeList object into the ViewState so when I change page I don't need to hit the database each and every time.
My question is: Is this how the ObjectDataSource works? Does it store it's data in the ViewState and not hit the database again unless you call the .Select method? I like to try and get the best performance out of my applications and hit the database as few times as possible but I don't really like the idea of storing a huge list in the ViewState. Is there a better way of doing this? Is caching per user a good idea (or possible)? Shall I just hit the database everytime instead of storing my huge list in the ViewState? Is it sometimes better to hit the database than to use ViewState?
I have created an ASP page to display records for auditor review and response. The page consists of two repeaters that display 5 rows from a database at a time. for each row displayed, a RadioButtonList, containing two buttons is attached. If the second button is selected, an input text box is displayed to allow auditor comments.
My situation is that I cannot find a way to identify which row is being selected? When I select the Button that should enable the text box, I'm receiving the following error:
"Object reference not set to an instance of an object"
I'm just starting out in ASP coding and would like to know what I'm not doing right?
I have a page that successfully displays a gridview. I am not able to select any of the rows. I put a breakpoint in the GridView1_SelectedIndexChanged method but it never gets executed. When I click on the "selected" column in the row I want, I just get the The page cannot be displayed message in my browserIs there something I need to do to make the rows "selectable"
I have a dropdownlist that controls what the users see in the gridview. I want to be able to have the users select "All" as an option. For example the drop down would for years would show: All, 2010, 2009, 2008. How do I code for the user selecting "All"? I am using ASP.NET 3.5 and C#
I am sure it must be a way to do this but I don't know how. I have a gridView2 that is called onto the page from a GridView1. I have enabled select on the GridView2 and need to get the values inside the cells. I thought about using SelectedDataKey but I need a way to select the row in the GridView using code.
May be I'm trying to run before I can walk, but here goes, I find coding for ASP so frustrating it's just not logical JIM!Anyways after my rant, as I'm a huge fan of the listview control in WinForms I'm trying to get the hang of it in ASP, wth not much luck so far.
i have a gridview that contains a couple of bits of information (email and and emailId) that i want to get and update to a database.
e.g. when i click a "select" button in my gridview i want to take the email and email id from that selected row and insert it into a database using a custom function. Having taught myself C# i'm still quite green to all the code.
The intension is to get the all text file names in the drop down present in a particular location. When a user selects any filename from the drop down, it will show the data which is in that particular text file in a GridView.
I've done both the steps and it's almost complete but i stuck on a small issue. Probably because of non-usage of ASP.NET for a long period of time. The problem is, the drop down only selects the default value not other values.Here's my code for DropDown Selected Index Change
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e) { DirectoryInfo di = new DirectoryInfo(@"C:myLogs");
I am trying to use GridView in my asp.net page. My requirement is to select an entire row by clicking at any place(field) in the row. Is it possible to accomplish this without using Links or buttons for the fields..? I have searched the net but couldnt find any answer. Is it the GridView designed not to allow selection of a row..?
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
Again, I am new to the ASP.NET world, and I come from a Windows Forms background. I'm working with an ObjectDataSource that retrieves a collection of business objects. With the collection, I am going to be binding it to a CheckBoxList and other various controls. The business object that I am using is an Employee.
To get all of the employees, I create an ObjectDataSource and set the "Select" method. I then set the DataSourceID of the CheckBoxList to be that of the ObjectDataSource. When I load the page for the first time, I see all of the employees. Now, the user goes through this page and selects all the employees they want to see information about (by checking the box next to the employee name). Finally, the user hits the button called "Display." Upon postback how do I get a list of those employees? I've tried the following solution, but I'm not sure if it's the best practice in obtaining all those employees again. Here's my solution...
In the CheckBoxList, I set the DataTextField to the Employee's name. I also set the CheckBoxList's DataValueField. This property is a little different. I set this to be a UNIQUE IDENTIFIER, which can distinguish this employee from other employees. Now, when the user hits the button "Display" I use my ObjectDataSource again and MANUALLY call ObjectDataSource.Select(). I cast the returned value as a List<Employee>. Finally, I iterate through all list items in the CheckBoxList...
[Code]....
If the item is selected, I parse through my list of employees that was returned from the bjectDataSource.Select(). I use the item.Value and compare it to each employee's "key." If the key is found, I know that the employee is selected. I put this employee in another list called EmployeesSelected.
Finally, I take EmployeesSelected (which is a List) and set my GridView's .DataSource and call .DataBind() on the GridView.
Is this the "best practice" of re-obtaining the Employees that are selected on my page, or am I making this too complicated?
My problem is I get an "Object reference not set to an instance of an object." error at runtime on the line "ddl2.SelectedValue = cat1". Ironically I got this from an example on the internet and the only difference is my Cat1 varible which has the correct value at runtime.
I would like to enable/disable the field BagNo in my gridview, depending on the value of another field in the gridview called ScriptNo, when I click the edit button I get this message "Object reference not set to an instance of an object".
here is the code
Protected Sub GridView1_RowEditing(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles GridView1.RowEditing Dim row As GridViewRow = GridView1.Rows(e.NewEditIndex) If DirectCast(row.FindControl("ScriptType"), TextBox).Text = "TTA" Then
I'm trying to access and display certain data in my database using category ID's. I've added values to the links in a link list and I was to have the selected value as the one that determines the selection in the selection statement. For example, "SELECT [ID_key] AS ID_Key, [Title], [Source], [PublicationDate], [Url], [CatID] FROM [Newsarts] WHERE ([CatID] = Linklist1.SelectedValue)". I know Linklist1.SelectedValue doesn't work or it may work and I don't know how but I want to be able to use the value selected from the previous link. Is there a way?
Also, after all the data is displayed, I would like them to become links themselves. Basically, I want to choose a category, then choose an article in that category, and they hit the link to display the article's content.
