Web Forms :: Error On Invalid Value In Dropdown With Autopostback True
Feb 3, 2011
I am getting the following error as Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation. when an invalid value is passed in dropdown with autopostback=true. What should I do. I want the solution with "EventValidation=true" and "ValidateRequest=true" in the Page directives. Also without any Custom Error Pages Enabled in web.config file i.e Custom Error Pages are off in web.config file.
It took me a little while to figure this out, but the AllowPaging="true" on the FormView seems to be the culprit. I don't have much experience paging from a FormView, but for this requirement the customers wants this kind of UI.I have a FormView with DefaultMode="Edit", which is bound to an EntityDataSource. One of the entity's properties, "ExternalID", determines whether some of the other properties in the entity are read-only. For example, if IsExternal==null, the FirstName, LastName, and Email fields should be rendered as TextBoxes. If IsExternal!=null, the 3 properties should be rendered in Label controls.
I have a Cascading drop down list that is working fine to load the correct lists however I would like to have the last one initiate a query and display a datagrid on the same page containing the results of the query. Without Ajax involved this seems rather easy by using autopostback on the drop downs. If I could do it through Ajax that would be great but I can settle with having the page to reload to display the data. Right now I'm not sure how to do either. I enabled autopostback on the last drop down and wrote a method for it but I get an error at runtime saying:
In the postback option class, the autopostback property is not functioning (for true or false) to forcibly set the the post back event on web page load as defined at the MSDN Url http://msdn.microsoft.com/en-us/library/system.web.ui.postbackoptions.aspx
I have a dropdown list where the user can select a name, on change event populates a Session variable and at the same time populates a formview with the full record detail. I want to add a List Item that states "Select Name" but when I add this the page errors. Input string was not in a correct format.
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.
System.FormatException: Input string was not in a correct format.
Because the value returned from the dropdown list box is a string and not a numeric equal to the first name in the list.
AppendDataBoundItems is = true AutoPostBack is = true
because I want to update the page as a differnent name is selected. I guess I need to not load the form until an actual first name is selected. Uncertain how to prevent the Formview from loading at page load an until a name is selected and not when the dropdown is set back to "Select Name"
When I do a TextChanged event on slider1 (by dragging the slider, changing the value), the protected void Slider1_TextChanged(object sender, EventArgs e) event FIRES, however, the TWO other sliders, protected void Slider2_TextChange, and protected void Slider3_TextChange also FIRES. What gives? why do they fire when I am physically only sliding the slider1 across. The two other sliders values did not change on the webform, yet the event fired.
In order for the event to fire for slider1, I had to insert "Autopostback=true" in the <asp:TextBox ID="Slider1" autopostback="true" OnTextChanged="Slider1_TextChanged">. For <asp:TextBox2> and <asp:Textbox3> I did not put the autopostback event for now.
When I place a value in TextBox1 and then click inside TextBox3 (which is there to have a place to go to get out of TextBox1 and TextBox2) the value from TextBox1 remains and is displayed in the MessageBox.Show correctly.
When I pick a value from the drop down calendar extender in TextBox2 for a brief micro-second the value from the calendar displays in TextBox2 and then the MessageBox.Show displays and the value in TextBox2 returns back to the orginally set value. The MessageBox.Show shows the orginally set value.
For TextBox2 if I set AutoPostBack=false then the TextBox2 works correctly and keeps the date picked from the calendar extender but the ontextchanged="TextBox2_TextChanged" never fires.
I have an autopostback dropdown with a requiredfieldvalidator associated with it. If I click the submit button on the page without selecting an item from the dropdown, the validator will fire as expected. Then, if I select an item from the dropdown, the validator message goes away, but the postback does not occur. The postback only works if the validator has not fired first.Is this by design? How can I work around this so that the dropdown still does a postback when selecting an item after validator occurs?
Buenos nachos, to be brief, my question is: is it possible to allow users to add new items to a combobox at runtime without having the autopostback property set to true? I understand it needs to postback if a new item is added, but I do not want the box to postback if the user simply selects a different value!
The tag I currently have is below. Without having the autopostback="true", the comboxbox doesn't allow the user to add new items to the box >_<' Any thoughts?
have a ASP.NET page for mobile view.On that page I have this part:
While testing this on normal computer using IE7 IE8 it fires the AutoPostBack Control.BUT TESTING IN IPHONE THIS DOES NOT FIRES....ALSO THE DISPLAY IS WIERD BECAUSE A SEPARATE BOX APPEARS AT THE BOTTOM TO SELECT THE LIST.
I have several input pages where I autopostback is marked "True", when I enter the data or select the entry. The page flashes a losses its normal tab sequence. How can I mainatin teh Tab Sequence (focus)? Exmaples