I have a third-party CustomControl which requires some info for databinding or anything else what it happen in a postback event handler.
Trying to send this info via, say, dropDownList i face that this dropdownlist postback event handler isn't firing before CustomControlEventHandler, as it happens in ASP.Net. What is usual workaround?
Or I should never rely on server side transfer and try to transfer this info on client-side etc.?
try
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true"></asp:DropDownList>
note: AutoPostBack="true"
Related
I have some really weird stuff going on here.
I have the following RadComboBox and button in the master page:
<telerik:RadComboBox ID="rcbPesquisa" runat="server" CausesValidation="false" ShowToggleImage="false" LoadingMessage="Carregando..." HighlightTemplatedItems="true" OnClientKeyPressing="onKeyPressing" EmptyMessage="Buscar" EnableLoadOnDemand="True" EnableVirtualScrolling="true" OnItemsRequested="rcbPesquisa_ItemsRequested" AllowCustomText="True" AutoPostBack="true" OnSelectedIndexChanged="rcbPesquisa_SelectedIndexChanged" Width="350">
<asp:Button runat="server" ID="btnExcluir" Text="Excluir" OnClick="btnExcluir_Click" CausesValidation="true" ValidationGroup="Excluir" CssClass="btn" OnClientClick="return confirm('Deseja realmente excluir o registro?');" />
In the page, I have this validator:
<asp:CustomValidator ID="cuvExclusaoRelacionamento" runat="server" ValidationGroup="Excluir" OnServerValidate="cuvExclusaoRelacionamento_ServerValidate"></asp:CustomValidator>
What happens is: When i click the combobox, and it tries to load it's items, cuvExclusaoRelacionamento validator is called on the server, and of course things go south.
By the way... __EventTarget on cuvExclusaoRelacionamento_ServerValidate is empty
Unfortunately, and without seeing the full code I'm only guessing, I believe there is no way of getting around this due to the following settings:
ValidationGroup="Excluir" The ValidationGroup property assigned to an input control is the Validation Group which should be triggered when the control posts back; The ValidationGroup property of a validator control is the name of the group to which it is assigned; Finally the ValidationGroup property of a submitting control (which could be a button but can also be the input control) is the name of the group of Validators to validate the page against before posting back to the server. I should point out at this timethat it will not post back (server-side event handlers will not be triggered) if the validation fails. Given that the validation group of the control is the same as the validation group of your Custom Validator the validator will be triggered when the control attempts to post back to the server (e.g. when being clicked), if this validation fails it will not post back.
AutoPostBack="true" When you set the control to auto post back it will post back to the server when updated. Given you have an OnClick event I'm guessing you need to perform some server side action when the state of the control is changed.
CausesValidation="true" When set to true all validators assigned to the same "Validation Group" as the submitting control will be triggered when the control attempts to post back to the server. As I've said above, this will prevent post back (meaning the server-side Event Handlers will not be triggered) if the validation fails.
Given the information provided, I'm guessing that the best action you could take is to set CausesValidation="false" for the control. The validation can still be performed so long as you have a submit button (or other control which triggers a post back) elsewhere which is assigned to the "Excluir" Validation Group.
Note: I am brand new at ASP.NET. I'm actually going to training on Monday, but we have a hot project that required me to dive in and get done as much as I can.
I've got a textbox on my page, and I would like it to call an event on the server whenever it is changed. I don't care if "changed" means changed and loses focus, or just whenever a keyup happens. Either case will work.
The issue is that, for some reason, whenever I change my textbox and then remove focus, the server-side method is not getting called. Viewing through the debugger in Chrome, I don't even see any sort of AJAX call being made that would inform the server that a textbox was changed.
My Code:
ASCX File
<asp:UpdatePanel ID="UpdatePanel2" runat="server">
<ContentTemplate>
<asp:TextBox ID="tempTagBuilder" runat="server"
CssClass="depBuilder_tempTagBuilder"
ontextchanged="tempTagBuilder_TextChanged" AutoPostBack="True"></asp:TextBox>
</ContentTemplate>
</asp:UpdatePanel>
ASCX.cs File
//whenever the text is changed
protected void tempTagBuilder_TextChanged(object sender, EventArgs e)
{
System.Diagnostics.Debug.WriteLine("Hit");
}
Anyone have a good idea of what my issue might be?
Update 1:
I got it working (somewhat). I had to go into the updatepanel's properties and add the textchanged event to the triggers collection. However, now whenever it sends the update it is emptying out the other textboxes on my page!
It doesn't fire because it's in an update panel most likely. Seems the updatepanel requires you to set a trigger for the event.
Problem with textbox inside updatepanel - not causing OnTextChanged event
I have an ASP.NET form with a few controls and a submit button at the bottom, all inside an update panel:
<asp:UpdatePanel runat="server" ID="upContent">
<ContentTemplate>
<asp:TextBox runat="server" ID="tbxMyTextBox" AutoPostBack="true" />
<asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClientClick="return doStuff()" OnClick="btnSubmit_Click" />
</ContentTemplate>
</asp:UpdatePanel>
If I write something in the TextBox and click 'submit' immediately (without clicking out of the TextBox first), the changes are not recorded (as seen in the server-side event handler). However, if I write something in the TextBox, and then change focus to another control, an AutoPostback happens through the UpdatePanel and then clicking 'submit' does recognize these changes. How can I force this content to update right as I click the submit button, while still running both the clientside and serverside events attached to it? Thanks!
Is is possible that your text-box gets cleared due to some on-submit/on-click event handler? I will suggest you do use some tool such as Fiddler to inspect the POST data in request. Or you can put a break-point at your server side code and inspect the request data. Look for particularly Request.Form[tbxMyTextBox.UniqueID] - i.e. look for presence of value for your text-box's name (name property at client side which corresponds to UniqueID property at server side). If the request contains the value typed in the text-box then something is happening on server side but good news is you can always retrieve the value from Request object. If the value is not present in the Request object then it means that client side code is clearing the value before the submit.
If an onclick method returns false, it cancels the action that the button would normally perform. As your button would normally submit your form, but it appears not to be submitting, your client side javascript code in doStuff is probably returning false.
I am trying to attach a server-side event to lookup the city/state for the user-entered zipcode in a field like the one below.
<asp:TextBox ID="TextZipcode" runat="server" CssClass="inputtext" Columns="10" MaxLength="10"></asp:TextBox>
Since there is no lost focus event to capture, has anyone had any luck getting this to work?
Sure, why not? Just attach a JavaScript handler and have it invoke an AJAX action.
I'm trying to wire up a CheckBox to handle an event when check/unchecked. If the user has JavaScript enabled, use that, otherwise use a postback.
Here is my code:
<asp:CheckBox ID="ApplicationInProcessCheckBox" runat="server"
Text="Application In Process" AutoPostBack="true"
oncheckedchanged="ApplicationInProcessCheckBox_CheckedChanged"
onclick="return false;" />
The return false in the javascript onclick event is disabling the postback. However, it also won't let the box check or uncheck. (I have more code to add to the javascript event... I just want to get the concept working first).
What am I doing wrong?
I think we can't post back on clicking checkbox without Javascript enabled.