I have put a user control on my default page. The user control contains a label and a textbox. When I am trying to access the user control from the default page in the codebehind it says
Object reference not set to an instance of an object. I am wanting to do something like this:
How to access userControl's properties, when use FindControl method?
View 7 RepliesI want to use a couple of instances of the same control on a page. The user control is intended to display a list of records in a repeater. The aim is that the second control will show a list excluding the IDs in the first control The control has a number of public properties, including IDsInThisList, and IDstoExclude. The query will exclude the IDs in the second property.
What I would like to do is get the record IDs from the first instance of the control (IDsInThisList), and pass them to the second contro as the IDsToExclude.
I have a test page where I am setting the properties of the controls in code. As you might guess, it's not working! The first control displays the top 3 items, as desired, but the second display the records 1-7, rather than records 4-10 because it is not receiving the IDstoExclude from the first control When I response write the IDstoExclude from the first control in my testpage, the string is empty. (if I do it from within the control, it shows the IDs)
How can I get the controls to fire in order and pass values to each other?
Screen grab of test page + uc and test page code attached
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i created a user control that has a template container.
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This is control is placed in a repeater which lists some customers. The customer is than bound to the user control. When the name template is instantiated in the container, the customer object is not yet available, but I need to access its name because it needs to get parsed before.
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Question: How can I access properties set for the user control BEFORE the template container is instantiated?
I can load a generic user control just fine in my WCF service doing the following:
UserControl userControl= (UserControl) new Page().LoadControl("~/UserControls/MyControl.ascx");
However i can't seem to find any way to do this
MyControl myControl=(MyControl)userControl;
The reason i need to do this is because my user control has a custom property, person, I need to do the following:
myControl.Person=new Person();
essentially i need to simulate:
<%@ Reference Control="~/UserControls/MyControl.ascx" %>
which normally goes inside asp.net page or master-pages.any way of doing this in an Ajax Enabled WCF Service?
I am new to asp development but have been around c# for a while. Basically I am trying to create a page which will pull data from a database and then for each object it creates I would like to add a user control which is built to represent that object. So basically I have tried quite a number of things to get it to work but for some reason I can't figure it out! How can I programmably add user controls and then set their properties from a 'master' page which hosts the user controls?
View 3 RepliesI have search for a long long time and could not find a solution to access to grid view's column properties. I have binded a grid view through this method, the bindGridView function will return a table with columns and rows.
The problem here is I cound not access to columns properties such as Grid_View.Columns.Count or Grid_View.Columns[0]."something". It seems like the grid_view does not have any column. But I can access to the Rows properties.
I have put this code within a (!IsPostBack) and set the AutoGenerateColumns to true?
I need to access to columns badly as I need t add additional column to the binded grid view.
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Is it possible to access textbox text properties from codebehind when gridview is edit mode? for example I can access label's text properties on gridview row databound event.
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So I do not like use Text='<%#Eval("ColumnName")%' this method. I want to manage textbox text properties dynamcily codebehind when click the edit button on gridview. When I clik the edit button these code blocks runs
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but rowdatabound event fires again and couldn't find label control. It looks for textbox control to bind data but I can not manage this step.
I am in need of some assistance in regards to how to best set the values of properties for a Web User Control which is being included into a cell of a GridView with dynamically created columns. I have tried a few different approaches, but can't seem to get a satisfactory result. Also, to be completely honest, I am not really sure if I am using best practices for what I am trying to accomplish.
First off a little background:I have a GridView for which we will never know the exact number of columns at run time. The columns are predicated by user selection. I am creating the command text for the DataSet on the fly and then looping through the columns of the resulting DataTable in order to use custom TemplateFields. This works ok for just printing out the row values but not so much for when I need to insert the Web User Control into a cell.The Web User Control is in essence a collection of image links which are used as a "Quick Nav" tool. I need to pass the values of 2 fields from each DataRow to the control via properties (for example, CustID and ProductID). I am using custom TemplateField classes inheriting from ITemplate for displaying my fields and extending the DataBinding event like so: [Code]....
This won't work for my User Control as DataBinding is called after the control is loaded into the page and I need the properties to be set before the Page_Load event of the control is fired.Is there a GridView event I should be looking into instead such as RowCreated or RowDataBound? Or should I modify how I loop through the DataTable by doing rows first, then the resulting columns as I've seen done elsewhere?
I have a nested gridview which has been working fine. Now I need to turn the inner gridview off based on some condition: a IF block is added to the existing RowDataBound event of the outer gridview. Now I'm getting "the Object reference not set to an instance of an object" error. What should be the proper way to go about this? The code:
[code]....
In addition, is there a way to "switch" columns of the inner gridview? For example, column 1 is "City", column 2 is "Price". If user selects to sort by "Price", I woud like column 1 be "Price" and column 2 be "City". Is this has to be done programmatically or if there's other way?
I need to access a control inside a repeater and change its properties. To enable it or not. I got an erorr message Object reference not set to an instance of an object. Here is my code inside a method. protected void
rptCAP_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
LinkButton lnDel = (LinkButton)rptCap.FindControl("lnkDelete");
lnkDel.Enabled = false; //<<<<< this is where the error occur
}
The name of the repeater control is id="rptCAP"
How do I access a property of a web server control?
View 2 RepliesI have added a static string variable inside a web page with it's class named VersionBase. The class is public, the variable is public, why can't I simply do VersionBase.MyString from anywhere inside the project like I can do with any other class?
View 13 RepliesI have an asp table with 15 rows and 12 columns, each cell as an ID and the cell names are like Cell1, Cell2, Cell3, etc.
I need to change the background color of the cell but the name of the cell comes from a string.
Something like:
strCell = "Cell3"
strCell.bgcolor = "Red"
How do I "convert" this string to access the cell properties?
I found this function on [URL] It works great and I can get the properties and display them in separate binds. This is how I call the function, as shown In the link above
SELECT userid, username,
dbo.aspnet_Profile_GetProfile(userid, 'FirstName', DEFAULT) AS FirstName,
dbo.aspnet_Profile_GetProfile(userid, 'LastName', DEFAULT) AS LastName
FROM aspnet_users
However, i cant get it to work with a simple querystring...
<SelectParameters>
<asp:QueryStringParameter Name="username" QueryStringField="user" Type="String" />
</SelectParameters>
I want to fetch a users First and last name with a querystring, for example (default.aspx?user=DemoUser) But it doesn't work, it displays the latest entry in the aspnet_profile table. Btw, im trying to display it in a formview.
Here's the scenario: A class based on System.Web.UI.Page has been created. A number of content pages derive from this class. All of these content pages use the same master page. The content pages define controls which need to access things on the master page (in code-behind). This is fine - no problem. In particular, each content page has its own data grid. The grid on each page has the same name, so that common code can reference it. In fact, some event handling for the grids on each content page is identical, so would like to factor that code to the base class. Interestingly, I can actually define the event handler entirely in the base class, with no stub in the content class at all, because the wire-up of event handlers uses the event-handler name defined in the grid, and that name happens to be found in the inherited base class. All good and dandy... very cool in fact. The problem comes when the code in the base class needs to access any of the common elements from the content page's master. Remember, the master is the same, and I know the type of the master. I would like to do something like this in the base-class code:
((myMasterType)this.Master).PropertyofMaster=xxx;
The problem is, that myMasterType - the type of the master page the content pages are using - is not available at compile time, at least not from a class definition for a base page. I've found articles that claim that the class name of the master is available - and it is, but not from a separate class. I CAN see it and compile with the master's class name from, for example, the code behind of the various content pages. But the actually class simply isn't available, it seems, from a pure class (the base page class). Judging from other times this question has been asked, here are common misunderstandings offered as solutions: 1. Use a page directive to declare the master type. This is not even vaguely a part of the problem, as the issue is not code in the content page, but in a separate base class which content pages inherit from. That base class is a pure class -- no .ASPX file at all. 2. Pass a reference to the master object from the content page to the base class. This can be done, but is pointless, because I can already get it, using "this.Master" from the base class! But because the type of the master is not available at compile time from the base class, it can't be passed from the content page either - unless it is passed with type MasterPage, thus losing all the properties/methods publically defined in the specific master page class. 3. Move the base page class out of the App_Code folder because the app_code folder is compiled before the other classes, and thus before the master page class. Doesn't work -- put the master page class file right in the same folder with these content pages and their master page, and the master page class is still not available at compile time from within the class. Re-summarized: Base page inherited by content pages. Content pages all use a common master page. Want to access the public properties of that master page from the base page, at runtime. Barrier is that I can find no way from within the base class to cast the master page object to the actual master page subclass being used.
I have created a Master Page and exposed a Literal control on it by way of a public property.
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In my content page I have referenced the Master Page like so :
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However in my content page code behind I cannot see the custom properties of the master page in Visual Studio.
I would like to ask you what is the best practice for developing composite user web control with multiple controls inside from the stand point of dealing with properieties. In my situation I would like to use header menu bar with logos, buttons, java baset visible/hidden menus itc as web control. I was successfull in implementing new control in my project.
But my question goes to issue of properties for ALL OF controls. I know how to hard code all required properties like: text, visible, enable for all controls. It's a lot of work. ( This is the very edge of my asp.net comprehension ) Is there a more elegant way provide an access to controls's properties without hard coding seperatelly?
I'm using ASP.NET MVC 3.I would like to create an action filter to determine if a user can access a view. I have a User class with properties like IsAdministrator, IsTrusteeUser and IsAuditUser. How would I create an action filter to block certain users if the don't belong in some of these roles?And aslo how would I use this in my views to hide/display certain controls?
View 2 RepliesIf the answer to this question exists somewhere, I'm no good at searching for it. This is sort of a simple question, the response being two parts: (1) is it possible? (2) if so, how?
I've created a web user control for my site's footer. In my web.config I have it registered like this:
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Then, within the pages on my site, I simply insert it like this:
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But obviously, that didn't work. I get this error: The type or namespace name 'FooterControl' could not be found (are you missing a using directive or an assembly reference?)
So I'm really not sure what to do at this point. I can put all of my code in the ASPX file and make my life easier, but I would kind of prefer not to.
I have several usercontrols which are loaded based on business logic.However, all of them have webcontrols whose selected/entered value needs to be accessible in parent page on an event.Since there can be any combination of UserControls, I do not want to load all the UserControls in the Parent Page, since they are heavy.
I would like to load only those controls which are supposed to appear on the page, yet access the value from the usercontrol which caused the postback. (I would rather not access using Request.Form) (ViewState is open, but unsuccessful to store value in parent page's viewstate in onClick)Here is a sample scenario
Page: Home
Dynamically Loads: UserControls1
UserControls has TextBox tb and Button btn, causing onClick
When btn is clicked, I want to get value of tb in parent page on PostBack, Page creates UserControl2
i have a multiple user controls, each user control has multiple properties, i am loading those controls dynamically in my aspx page,i save the user control name in a hidden field in my aspx page,so i can know whats usercontrol are currently loaded,now i want to set/get some values for Currently user control properties,how can i know the properies available for that dynamics loads control ?also how to know the class for that control ?
View 3 RepliesOn DBML I have two entities as Parent, Child. I am trying to assign Child class properites in a Parent.
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I am getting the following Error:
Cannot access a disposed object.
Object name: 'DataContext accessed after Dispose.'.
I want to use Profile Properties to keep some user information and move them between pages. I'm wondering if those profile properties are keeping data session based or when I assigned them is it same for all sessions/ Is this a safe method to use them:
<anonymousIdentification enabled="true"/>
<profile enabled="true">
<properties>
<add name="userid" defaultValue="" />
<add name="password" defaultValue="" />
<add name="username" defaultValue="" />
</properties>
</profile>
I have a user control (i.e. ascx) that comprises of two related list boxes (i.e. once you change the selected item in one list the contents of the other list update). I'm adding this user control dynamically to a page on the click event of a button (i.e. using LoadControl).I wish to set the list box datasource properties, as well as the default selected item of the parent list from my parent page so I created public properties in my user control to accomodate this. I also created an event in my user control that notifes the parent page when the selected item changes in one of the list boxes so I can update the contents of the other list box.
I understand that I have to recreate the user control on every postback in order for it to function correctly but I'm not sure exactly how I should be doing it. I've shown below what I have currently - whilst it works the problem is that on postback I'm always creating the user control with all its default properties and then updating the properties that need to change(?). For example, when the choice in theparent list box changes the datasource of the list box is set twice (once in AddControl and then again in OnParentChanged)? As the contents of the list boxes originate in a database it means I'm making unnecessary calls to the database (unless I do some something like store each unique set of data in the ViewState).
I'd be very grateful if someone could review how I've done things and illustrate how perhaps I should be doing things. I'm not sure if the way I've done this is considered the 'correct' way. For example there may be a better way of doing things would avoid setting the properties twice? I'm a bit unsure of the way I've set the datasource properties of the list boxes and bound them. I wished to set the datasource from the parent page because I might have a second user control on my page that may also use the same datasource and I could reuse it (as opposed to each control making its own call to the database) so I'd like to keep this feature if possible.It would be great if posting code in reply that you use my example as a guide so I know what you're referring to.Here's the code for my user control:
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Here's the code for my containing page:
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