Web Forms :: Using The RenderControl Method With An ImageButton
Oct 1, 2010
I am trying to find out what html is generated when a control is rendered. For most controls, the following worked fine: Dim tempbuilder As New System.Text.StringBuilder() Dim tempwriter As New
System.Web.UI.HtmlTextWriter(New System.IO.StringWriter(tempbuilder))
Dim generatedhtml as String Me.imgImage.RenderControl(tempwriter) generatedhtml = tempbuilder.ToString()
However, when I tried doing it with an ImageButton, I recieved the following error: Control 'ctl00_cphExampleContent_imgButton' of type 'ImageButton' must be placed inside a form tag with runat=server. What can I do to avoid this?
I am using TreeView Control in Asp.net. I have placed this control inside a panel. The tree control is completely binded (we don't want populate on demand) with an Xmldatasource during a callback and then I call Panel.renderControl to return the response (HTML) to the client side callback handler. Problem: 1. The tree expand/collapse (on click of plus sign) is causing postback whereas when I normally bind a tree with xml during postback and without using renderControl of container control, the expand/collapse (on click of plus sign) is being handled at client side. I want to stop this postback and allow tree node to call javascript to toggle nodes as it does when tree is binded and renderd in case of normal page life cycle.(when render control function is not used)
why asp.net does not render a dropdownlist with the autopostback property set to true when using the RenderControl method.
eg
Dim sw As New IO.StringWriter Dim tw As New HtmlTextWriter(sw) Dim table As New Table
[Code]...
my output renders the dropdown list without the onchange="javascript:setTimeout('__doPostBack(ddl1','')', 0)" that is generated by asp.net when using the dropdownlist normally.
If I use an ImageButton or LinkButton, I just noticed that when clicking either, the Page_Load method executes before the method specified in the OnClick. Can this be avoided so that the method in the OnClick is triggered instead of Page_Load?
I have read many posts in the past about TreeView in Custom CompositeControls and using RenderControl but have yet to see a solution. I declare a new Tree in the CreateChildControls method and in the render I try to call the RenderControls method and it gave me an object reference not set to instance of an object error. I have set the SkipLinkText to Nothing, String.Empty and "". Once I do that I get the second stack trace. The control worked when it was a control on the aspx page.
If I have an HtmlTextWriter with some content in it, is it possible to append the output of ontrol.RenderControl to the existing content of the HtmlTextWriter directly?
Or do I always have to output to a separate HtmlTextWriter/StringWriter/StringBuilder and then append the StringBuilder?
I need to get the html of a chart control built at runtime. When I call .RenderControl, I get System.NullReferenceException. What could the problem be? Is there another way to go about this (saving as image)? Below is my code.
I then use .RenderControl on both rblQuestion and rfvQuestion, concatenate into a string then use the HTML String to populate a PlaceHolder.
This seems to work fine, all appears as expected apart from the RequiredFieldValidator - I get a red asterix (My ErrorMessage) next to each RadioButtonList - But this appears as soon as the page loads, not on a post/button click.
I want to do a Jquery POST and get a chart using renderControl attribute of CHart which will return HTML attributes back to browser. The CHart is created dynamically based on parameters passed from post and from model. I have successfully done this on WEbforms,
However the same with MVC give a empty image. The handler doesn't perform the same in MVC2 3.5. I went near to 50 sites now.
I can't use other solution like base64encoding as IE6, 7 don't support it.
What I'm trying to do? I have few data parameteres to be sent (POST) to server and in response get the Chart image as tag along with other attributes and data appended in HTML form and sent to browser, all this to be done using JQUERY. No postbacks to be used.
I have badly searched on google, bing nothing turns out to be valuable.
I have a custom web part that I am trying to call the RenderContents method on, but the results only contains the surrounding div for the web part, and not any child controls.
Take for example this simple web part:
namespace MyWebParts { public class MyTestWebPart : WebPart { public MyTestWebPart() { this.CssClass = "myTestWebPart"; } protected override void CreateChildControls() { base.CreateChildControls(); this.Controls.Add(new LiteralControl("Nothing here yet.")); } } }
Then, in an http handler, I'm trying to instantiate this web part and call its RenderControl method. The result is <div class="myTestWebPart"></div>.
Does anyone know why I am not getting my controls from CreateChildControls also added to the output?
I am using the following code to export a Gridview to an Excel spreadsheet. It works great until I select more than 10 records. At the 11th record I get an error on the line of code that reads....GridView1.RenderControl(hw)The error reads....RegisterForEventValidation can only be called during Render(); 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.InvalidOperationException: RegisterForEventValidation can only be called during Render();Source Error:
I don't know what I'm making wrong.I have a submit button, and on click it should execute the funktion in the code behind, but I get the error that the funktion is undefined.this is my code in the .aspx webform:
I am creating an Asp.net web site which will support dynamic data. When I am creating a dynamic web site from Scratch (from template in VS) all is working fine. But when I am trying to add dynamic entity (.edmx) file and running the application I am getting following error
"The method 'Skip' is only supported for sorted input in LINQ to Entities. The method 'OrderBy' must be called before the method 'Skip'. "
I created an image button called "pic1" with the OnClick feature. When clicked it runs "btnClicked". In the sub "btnClick", how would I get information? One example is to get the button tooltip. I tried this: request.form.item("pic1.tooltip"). That did not work.
I have a multiview, with constant back and next imagebuttons, that are positioned and characterized by an external css style sheet. One of my views however are of different widths from the others so this view needs to have the buttons positioned accordingly. I am trying to do this in my pagebehind VB.NET code with Visual Studio 2008 3.5, of assigned similar Imagebutton.CssClass = "~/css/classname" where classname is the name of the class I wish to set dynamically to the buttons.
Public Sub FwdDetermineMultiView() If mvAddReferral.ActiveViewIndex = 0 Then BuildReferralInfo() mvAddReferral.ActiveViewIndex = 1 ibtnPersonalInfoBack.Visible = True ElseIf mvAddReferral.ActiveViewIndex = 1 Then BuildContactInfo() mvAddReferral.ActiveViewIndex = 2 ibtnPersonalInfoBack.CssClass = "~/css/mvPanelNavbtnLeft1245" ElseIf mvAddReferral.ActiveViewIndex = 2 Then ICategories.CategoryList = CountChecks(lbCategories) If atLeastOneRowSelected() = True Then ICategories.Category = GetCategoryNames(ICategories.CategoryList) Session("Categories") = ICategories mvAddReferral.ActiveViewIndex = 3 Else MsgBox("You must assign at least one category", MsgBoxStyle.Exclamation, Wrn) mvAddReferral.ActiveViewIndex = 2 End If ElseIf mvAddReferral.ActiveViewIndex = 3 Then Response.Redirect("~/aacess/Referral/ReferralSummary.aspx?") End If End Sub
I need to replicate the Web Forms ImageButton control in my MVC app and I have read about Html.SubmitImage. However, this helper method is not appearing in my list of options in Intellisense. Here is my code :
Is there a way to assign a byte[] as Image to a ImageButton?Currently i'm using the Aspx:BinaryImage which allows me to assign a byte[] as Image.Problem is that the BinaryImage does not support a onClick event.
I am using an Imagebutton to open a webpage. This code works but what I wonder is if it is possible to have a new browserwindow opened with yahoo.com instead of
I have a ImageButton on a master page and a text box. Basically I set the default button to my image button and in the master page I have the following code:-
Code: Protected Sub butSearch_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles butSearch.Click If txtSearch.Text <> "" Then Session("SearchFor") = txtSearch.Text Response.Redirect("~/Search.aspx", True) End If End Sub
When I click on a menu button which has its navigateurl set it works but if I select a different button which loads another content page it does not.
