Setting The Src Of An Image Tag Getting Null Reference Exception?
Dec 6, 2010
We have a chart on a page that current is hard coded with test data, client likes and we are trying to now link to live data.I have tried different things in the code behind to build the url and keep getting Null Reference Exception even though when i debug the url is there and complete. I can take the value that i get in debug and paste directly to the browser and the chart works. so i know that im building the url correctly, but setting the .Src of the image in the page_load event doesnt seem to be the correct way to populate the image..Here is the complete link that is built in the code behind that is passed to the src of the image control.http://chart.apis.google.com/chart?hs=300x265&chd=s:bD&chdl=DVDs|DVDs+with+Scracthes&chdlp=b&chl=44|5&chma=40,60,0,40&chtt=DVD+Report&cht=p3&chco=751010|FFCC33 In the page load event i have the following:
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I place a break point on the line where i set the src and as i step thru everything is correct and the src is being populate with the correct link, but when i step past that line, then i get the null reference.Now why is it that i can paste that link to the browser and it works.. and if i hardcode that link in the image src on my aspx page and comment out the code behind it works there also..
I'm getting a null reference exception whenever I try to databind this datatable to the Gridview. I know for sure that the datatable has data. I've checked it.
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I get the error when it gets to the last line here..
I have a TextArea html helper method I'm calling in a foreach loop. Basically, when I initially load the View it works fine, but when i reload the View and load postback data, the same TextArea throws a NullReferencException and yet the variable I'm using in the TextArea as the name of the TextArea is not null. I've attached a picture below for demonstration:
if it's difficult to see, the blue arrow below is pointing to the variable used to name the TextArea. Again, it works on initial load, but it errors out on postback when the page is reloaded. I'm not sure what's going on.
My controller calls a class in my model which is getting data from a REST web service. The class in the model then passes the data back to the controller using an IList, like so:
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My problem is this: The data that is held in the IList isn't there until the user has done a search in the View, submiting a form. This is a basic search function with 2 textboxes and a submit button in a form. When the user clicks submit, the controller action is called, the web service is then called, and the data in the IList gets populated. The problem is that in the View I am using a strongly typed view and my model reference in the foreach loop throws a Null Reference Exception because there is no data in it, because a search has not been conducted yet... [Code]....
So, how can I have the above foreach loop in my view if there isn't any data in the model until a search has been conducted? Is there a better way that I should be doing this?
Essentially, what's the best method for passing data back to a view that is based on a form submittion?
I am using httpcontext.Current in one my action method and i created the ms test method for testing this action and also i created the Mock object for httpcontect,but when i am trying to run the MS test script i am getting null reference exception from the line which i am using httpcontext.current in the action method.
When run, I can successfully authenticate and then when I attempt to view this particular content page I get an error on the page load where I'm trying to populate the dropdownlist. The error I get is a Null Reference exception. I don't fully understand the page lifecycle of an asp.net page, but I also don't understand why the page compiles successfully and its only when run that I get this exception. It seems that the control is not created when the page_load command is called. How can I change the contents of a dropdownlist on page load of a content page that requires authentication?
let me see if I can explain this clearly. I have a gridview control and I am trying to use the Edit function. In my gridview, there are numerous rows. I pick one to change and click Edit. I then see the boss name in my gridview and click "Change". When I click Change, I'm expecting two fields to appear, one is a label, the other is a DropDownList. I get this error when I click:
System.NullReferenceException was unhandled by user code Message=Object reference not set to an instance of an object. Source=App_Web_lzmklgbg StackTrace: at Training_TRManageOrg.LinkButton1_Click(Object sender, EventArgs e) in d:projectsediting.aspx.cs:line 108 at System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e) at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) InnerException:
I am stuck into a problem, i have a user control ProductListing.ascx that contains ListView binded to an object datasource, SelectMethod and SelectCountmethod are provided as well. Everything works fine but the problem started when i add another user control declarativlly Filter.ascx in the productListing.ascx. I want to assign value to a public property MaxPrice in Filter.ascx. I am trying to set this property in the SelectMethod of ObjectDataSource. Usercontrol "Filter.ascx" throws null reference exception when i try to set its MaxPrice Property.
I tried to acced the usercontrol in Databind method of ListView , it is accessible here but viewstate is empty at this point, i saved the value in viewstate in SelectMethod of objectDatasource but i cant access viewstate in ListView Databind. Its empty. Its a simple code and no rewriting to viewstate elsewhere.
Important: My Codebehind files are in a seperate project and .ascx files in seperate project
I developed a page in VWD 2008 and it works perfectly locally, but when I deployed it on the server every Page.FindControl() call is causing the NullReference Exception "Object reference not set to an instance of an object. " Can anyone help me out? Code is below
I' m using a web custom control to upload images and mark them as primary. all the flow is working fine but it fails to mark images as primary in a diffrent category(there are four categories in which we can load a image-,catalog,primary,misc).It works in - category but not in others when I debug it is failing at a condition in grey . If it is not an element of the Datalist item it would not even enter the loop. I' m lost and unable to find the reason.
I have a class that derives from System.Web.UI.Page and have set my pages to derive from this custom page class instead of Page. At runtime, the controls are never initialized and throw a NullReferenceException. I've changed some class names and namespaces in the pasted code to protect the innocent. The only thing that I currently override in my PageBase is OnPreLoad and I do call the base.OnPreLoad. I'll eventually add more functionality to this PageBase but for now all that it has is this:
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I've tried putting this into a class library (with System.Web referenced) and I've also tried moving the class into the web application and had the same results either way. As another strange twist, I have another class with derives from PageBase called IndexPageBase and it doesn't have this problem:
and right below that i have 1 condition to check for and then set the Text value of the 2 labels.hireMess.Text = "It Was Successfully!";hireEnd.Text ="You will be re-directed to your Pool in 10 seconds.";I compared the page to production and eveyrthing is the same and production doesnt have any issues.. not sure why its coming up null.The error comes up for the first label: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:
I am using dropdownlist in my view page with some values which will display corresponding ID(primary key of other table) in my database.If i leave my dropdownlist blank and save it in database then its showing null parameter error. Can you explain how to use this reference type to overcome this error
I have several text boxes in an asp:Panel. When the user hits Enter from any of those boxes, I want the form to submit as if they've clicked btnAddTag. (When the cursor is not in those boxes, I have a different default submit button.)
Im trying to resize an image. I have the original file and then try to resize it and save it to a new image.However, I get an exception because the value of stream cannot be null. This makes sense, but I dont know how to prevent it:
Value cannot be null. Parameter name: stream Description: An unhandled exception occurred during the execution of the current web request. Source Error:
I'm not even sure if this is the correct approach for this -
I have a DB that stores information, as well as a location to where images are stored
ie ProductImage = ~/ProductImages/BulkRetail.JPG
I'm using a repeater to list all the products, which works fine for all the labels I use but not for the image location. I'm using something like this, but it doesn't work:
I have a Silverlight control that is hosted within an ASP.NET application. The Silverlight control has a web service reference. The URL of this service is going to vary when we install the application for our customers. I need a way to be able to change this web service reference URL from within the web.config of the ASP.NET application. How can I do this?
This is probably something silly I'm missing but I'm definitely lost. I'm using .NET 4 RC and VS 2010. This is also my first attempt to use UpdateModel in .NET 4, but every time I call it, I get an exception saying Value cannont be null or empty. I've got a simple ViewModel called LogOnModel:
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My view uses the new strongly typed helpers in MVC2 to generate a textbox for username and one for the password. When I look at FormCollection in my controller method, I see values for both coming through.
And last but not least, here's are post controller methods:
