Web Forms :: Manually Invoking A __doPostBack Call?
Sep 23, 2010
I have a web forms page with a button that involkes a __doPostBack callback to the page. I would like to invoke this manually - by "manually" I mean from outside the webpage, for example by using wget.
I have a web forms page with a button that involkes a __doPostBack callback to the page. I would like to invoke this manually - by "manually" I mean from outside the webpage, for example by using wget.
i am doing this in my client side to make my page load and update a message that is inside and update panel, i associate the keydown event of a textbox control to this javascript:
[Code]....
but the problem with that is if the user type fast the page will do a lot of postback, and i just wanna make the last one, how can i afford that??
Clicking the link does perform the postback, as verified by a breakpoint in the code-behind. Also pasting javascript:__doPostBack('ctl00$c1$btnRefreshGrid','') in the address bar of the browser works with the same effect.
But when i deploy the project on the production server, it does not raise the event although i have checked that the function getting called but the event is not raised.
In short
* javascript:__doPostBack('<%=lnkSaveBtn.UniqueID %>',''); in javscript works using http://localhost:2000/myProjectName/Home.aspx
*javascript:__doPostBack('<%=lnkSaveBtn.UniqueID %>','');not works when using http://machinename/myProjectName/Home.aspx
I have tried using javascript:__doPostBack('<%=lnkSaveBtn.ClientID%>',''); but still does n't work.
i have explicitly added __doPostBack() on Button onclientClick event .
[Code]....
When I am clicking the button the Page_Load is calling twice.
But if I am adding below code inside page load ,page load is calling only once on button click.
[Code]....
and return true is giving me again twice page load ,but adding return true or false in attribute.add code is giving the same result ,only one page load call.
[Code]....
I am not able to understand what is going on exactly I try to add __doPostBack in different way.
I am calling a method with __doPostBack using the OnFocus event for the controls. However I need to update the values multiple controls when the server method executes. This actually causes on focus to keep firing. Looking for help. I tried using TextBox1.Attributes.Remove("onfocus") and then adding it the javascript after processing but it still keep looping. Here is a sample using to textbox's for simplicity:
I am having a content page in master page and an iframe in content page.
In content page i have dynamically created treeview and in iframe i am having a gridview. As i add or delete a row in iframe my treeview should automatically reloaded that value without entire page referesh.
Here point to notice is my iframe is a different aspx .
We have a base class that all our webpages in our application inherit from. I have a static method in the base class which when called will clear values from the application cache. Now the issue is this method needs to be triggered from a source outside the current application. I there any way this can be accomplished without creating an aspx page that will call this base method on page load.
I am new to ASP.NET but what i am trying to do is create a webservice (in C#) with a method that basically returns the IIS HTTP 202 Error Code (ACCEPTED) page.Is there any method that would automatically return this? Or would i need to write some sort of code that would cause the error message 202 to display?
I'm having troubles passing a parameter to a handler in it's query string. I have a gridview with an image column, this column is defined as a TemplateField, as:
As you can see, the ImageUrl is a call to a handler that receives the EmployeeID in the QueryString, under the name ID. When I run it, the ImageHandler method receives the following query string "ID=<%" instead of "ID=<the result of Eval("EmployeeID")>", and of course, it throws a FormatException when using it as an int to get the EmployeeID. (If I type ImageUrl="~/ImageHandler.ashx?ID=<%# Eval("EmployeeID")%>" (using " instead of ') the compiler returns the error incorrect server tag) The complete markup is:
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>" SelectCommand="SELECT [EmployeeID], [LastName], [FirstName], [Photo] FROM [Employees]"> </asp:SqlDataSource> <asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1" AutoGenerateColumns="False"> <Columns> <asp:BoundField DataField="EmployeeID" HeaderText="ID" SortExpression="EmployeeID" /> <asp:BoundField DataField="FirstName" HeaderText="FirstName" SortExpression="FirstName" /> <asp:BoundField DataField="LastName" HeaderText="LastName" SortExpression="LastName" /> <asp:TemplateField HeaderText="Image"> <ItemTemplate> <asp:Image ID="Image1" runat="server" ImageUrl='~/ImageHandler.ashx?ID=<%# Eval("EmployeeID")%>' /> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView> Could anybody tell me what am I missing here? Rafael
Im getting that error when try to call a __doPostBack on one of my pages, every page that i have in the project use __doPostBack function but in this particular page im getting that Javascript error.i was looking in the internet and the only thing i read is that this error happends when i have a unclose tag but i review the site and its ok.Error: __doPostBack is not definedSource File: htt://localhost:99/ProjectName/Disable.aspx
I'm sending a value (id) from javascript like this:
__doPostBack('',id)
and at the server side I get it like this:
var id = Request["__EVENTARGUMENT"];
the problem is that sometimes other controls also do stuff and the var id also get's value but not with the value I sent, but some control did.how do I send this value separately so that in var id only the value that I sent using js can be.
I'm having a problem with telerik RadGrid, I want to enable multiple row selection. I also want to go to the server whenever a row is selected or deselected. I created a javascript function to handle the Grid's client side events (OnRowSelected, and OnRowDeSelected). The functions look like this:
function onOperationRowSelected(sender, eventArgs) { __doPostBack("<%=myControl.ClientID %>", "rowSelected:" + eventArgs.get_itemIndexHierarchical()); }
The other function is very similar, the only difference is that it sends the string "rowDeselcted" instead of "rowSelected".
On Page_Load I check to see if the request is a Post request using "IsPostBack" and if so, I check to see if it's a rowSelected or rowdeselected.
My problem is when I select a first raw on my grid, a Post request happens (which is expected), however, when I select the second row, a GET request is issued, which (obviously) will result in IsPostBack returning false.
Got really strange Firefox issue. Using the Microsoft __doPostBack javascript function in web forms page. Used for tab control, we have got each tab click calling the __doPostBack function. Works ok on my dev machine with all browsers but got a colleague who has an issue if he leaves the page idle for circa 3 -4 minutes. After this delay if he selects a new tab which calls the __doPostBack function the call to theForm.submit(); just hangs and get requested timeout. No .net calls are seen in Firebug. The __doPostBack event is called just theForm.submit() function just doesn't execute. If he does not have this idle time works ok. It is also ok for him on all other browsers.
I'm trying to manually call the ASP.NET (3.5) javascript postback function __doPostBack from my javascript code. The problem is that the postback script block, that is normally rendered right after the beginning of the <form> tag (and the hidden fields), is occasionally rendered near the closing </form> tag. Is there any way to force it to be rendered near the beginning of the form tag? Also, how does ASP.NET decide when/where to render the postback client script block?
Edit > Additional Info: The javascript code resides inside a user control that references the __doPostBack function. The control itself does not contain any 'postback controls' that would call that function. (When I mention 'postback controls', I mean ASP.net controls that call the __doPostBack function and not the asp.net ImageButton and Button controls)
Based on what I've observed and @Brian's comment on the dependency of the postback script on the availability of 'postback controls' on the page, I've found that when the page contains controls that cause postback, the __doPostBack script block is rendered after the opening <form> tag and when there are none, it renders them near the closing </form> tag (or according to this it's not even supposed to be rendered). Now it would make sense for ASP.NET not to render the postback script if there are no controls that require it, but the apparent position of the script near the closing tag is the one that still eludes me. I haven't been able to find any documentation that suggests this behavior. All I've been able to find was this.
Add a 'postback control' and set its visibility to hidden via css (not the Visible property). eg. <asp:LinkButton ID="RequirePostBackScriptLink" runat="server" style="display:none;" /> (this is what I'm using) Add the control to the Page.RegisterRequiresPostBack and implement the IPostBackDataHandler interface.
Finally, as @Jonathan_Bates mentioned in his post, the proper thing to do is to wrap the reference to __doPostBack inside a function that is an event handler to load (or ready if you're using jquery). That way, there wouldn't be a need to depend on the actual placement of the __doPostBack script.
In my code behind, I use MyParam to query a database and bind the result to a gridview that's inside the MyPanel updatepanel. The updatemode of the updatepanel is set to conditional and in the postback part of the code I have MyPanel.Update();
The updatepanel works fine when I'm doing sorting and paging; only the panel is refreshed. However, when I trigger the updatepanel with my javascript, I see the traffic in firebug showing that the entire page is being refreshed.
When I am clicking the button the Page_Load is calling twice. But if I am adding below code inside page load ,page load is calling only once on button click.
and return true is giving me again twice page load ,but adding return true or false in attribute.add code is giving the same result ,only one page load call.