I have this control:
I'm trying to create a kind of validation, that whenever the user enters text to the TextBox, the "Add" button will be Enabled, and when the text is "" (null), the "Add" button is disabled.
I dont want to use validators.
here's the code:
protected void addNewCategoryTB_TextChanged(object sender, EventArgs e)
{
if (addNewCategoryTB.Text != "")
addNewCategoryBtn.Enabled = true;
else
addNewCategoryBtn.Enabled = false;
}
The problam is, that when the user enter's text, the "Add" button doesn't changes from disabled to enabled (and vice versa)...
any ideas?
Is it Web Forms? In Web Forms the TextChanged event of the TextBox won't fire by default.
In order to fire the event, you have to set the AutoPostBack property of the TextBox to true.
BUT, this would perform a HTTP post, what is kink of ugly, or you can wrap that in an UpdatePanel
A more elegant option, is to do that using jQuery, to do that in jQuery, you'll need some code like:
$(document).ready(function() {
$("#<%= yourTextBox.ClientID %>").change(function() {
var yourButton = $("#<%= yourButton.ClientID %>")
yourButton.attr('disabled','disabled');
yourButton.keyup(function() {
if($(this).val() != '') {
yourButton.removeAttr('disabled');
}
});
});
});
You'll need to accomplish this with Javascript, since ASP.NET is incapable of performing such client-side modifications. Think about it ... every time you pressed a letter inside the text box, it would have to postback and refresh the page in order to determine if the text box was empty or not. This is one way that ASP.NET differs from Winforms/WPF.
TextChanged events will make postback on server every time. You don't need to increase those request for such task.
You can use jquery to achieve this
var myButton = $("#btnSubmit");
var myInput=$("#name");
myButton.prop("disabled", "disabled");
myInput.change(function () {
if(myInput.val().length > 0) {
myButton.prop("disabled", "");
} else {
myButton.prop("disabled", "disabled");
}
});
JS Fiddle Demo
You just need to take care of elements Id when you are using Server Controls. For that Either you can use ClientID or set property ClientIdMode="Static"
Related
ASP.NET 4.7.2 Web Forms c# VS 2019
I am trying to use a modalpopupextender to prompt for new data for foreign key fields. Like the form itself, the MPE is built on the fly in code -- in this case the click handler for the hidden button that the Javascript fires off to build and show the MPE.
I read every single article on SO and the ASP forums and tried everything I saw there. No joy. I get the popup perfectly. Hitting OK closes the popup, but never fires the OK Event.
Here is the code:
//Building the form, we do this in OnInit:
// AJAX Update Panel
UpdatePanel PUP = new UpdatePanel()
{
ID = "PUP",
};
PlaceHolder.Controls.Add(PUP);
// HiddenField containing the field name to permit
// creating the correct modalpopup.
HiddenField HFPopupField = new HiddenField()
{
ID = "HF_POPUP"
};
PUP.ContentTemplateContainer.Controls.Add(HFPopupField);
// Create Hidden button to track the popup
Button BPopup = new Button()
{
ID = "BPOPUP",
UseSubmitBehavior = false
};
BPopup.Click += BPopup_Click;
BPopup.Attributes.Add("style", "display: none;");
PUP.ContentTemplateContainer.Controls.Add(BPopup);
// And create the background panel for the popup.
Panel PnlPopup = new Panel()
{
ID = "PNLPOPUP",
CssClass = "MpeBackground"
};
PnlPopup.Attributes.Add("style", "display: none;");
PUP.ContentTemplateContainer.Controls.Add(PnlPopup);
/// Event handler for hidden button.
protected void BPopup_Click(object sender, EventArgs e)
{
[snip -- code to get the dataset that is being filled]
UpdatePanel PUP = Placeholder.FindControlRecursive("PUP");
Table T = new Table()
{
CssClass = "PopupTbl"
};
TableRow TRTitle = new TableRow();
TableCell TCTitle = new TableCell()
{
CssClass = "PopupTitle",
ColumnSpan = 2
};
Label LPopTitle = new Label()
{
Text = [title of the popup]
};
TCTitle.Controls.Add(LPopTitle);
TRTitle.Cells.Add(TCTitle);
DataRow drData = null;
// Add Fields, and also the cancel and Add buttons
foreach (DataColumn DC in dsColumns.Tables[0].Columns)
{
TableRow TRColumn = [create a tablerow with 2 columns, a prompt and the input field]
if (TRColumn != null)
{
T.Rows.Add(TRColumn);
[snip]
}
} // end of foreach(DataColumn DC in dsColumns.Tables[0].Columns)
PnlWindow.Controls.Add(T);
TableRow TRButtons = new TableRow();
TableCell TCButtons = new TableCell()
{
ColumnSpan = 2,
CssClass="PopupButtons"
};
Button MPEBOK = new Button()
{
ID = "MPE" + sFieldName + "_MPEBOK",
Text = "OK",
CausesValidation = false,
UseSubmitBehavior = false
};
MPEBOK.Click += MPEBOK_Clicked;
TCButtons.Controls.Add(MPEBOK);
LiteralControl LCB = new LiteralControl()
{
Text = " "
};
TCButtons.Controls.Add(LCB);
//************************************************************
//*** Postback Trigger ***
//************************************************************
AsyncPostBackTrigger trigger = new AsyncPostBackTrigger()
{
ControlID = MPEBOK.ID,
EventName = "click"
};
PUP.Triggers.Add(trigger);
//************************************************************
//*** Cancel Button ***
//************************************************************
Button MPEBuhBye = new Button()
{
ID = "MPE" + sFieldName + "_BUHBYE",
Text = "Cancel",
UseSubmitBehavior = false
};
TCButtons.Controls.Add(MPEBuhBye);
TRButtons.Cells.Add(TCButtons);
T.Rows.Add(TRButtons);
PnlPopup.Controls.Add(PnlWindow);
AjaxControlToolkit.ModalPopupExtender MPE = new AjaxControlToolkit.ModalPopupExtender()
{
ID = "MPE" + sFieldName,
PopupControlID = "PNLPOPUP",
TargetControlID = "BPOPUP",
BackgroundCssClass = "MpeBackground"
};
// Add the MPE to the UpdatePanel.
PUP.ContentTemplateContainer.Controls.Add(MPE);
// Show the modal popup extender.
MPE.Show();
}
protected void MPEBOK_Clicked(object sender, EventArgs e)
{
[snip - this never fires]
}
I cannot find out what is happening here. Can anyone see something hinky?
Thanks
John.
You can't add a server side button or inject a server side button into the page DOM.
When you drag a asp.net button onto the form, BOTH the "mypage.cs" and mypage.desinger.cs ARE updated. The wire up of the button occurs at design time, and you would have to modify mypage.desinger.cs ALSO and ADD a button event stub.
So you can't do this.
A compromise would be to also add some js and have that HTML button execute a .click() method of a hidden asp.net button you drop into that page (that would give you the post back, and the running behind of a separate button event code stub.
This event resolution occurs at compile time - not at page render time. You have to drop that button onto the page.
I suppose you could adopt a standard that you always place right below that "div" on the page the button (hidden with style=none. And then as noted, have your injected code along with some js execute a click on the hidden button. Or just have the js button code execute a __doPostback("some value") and pick this up in the page on-load event, and then call the routine (function) from on-page load event.
I think better would be to use a jQuery.UI dialog, as that dialog CAN say load + use another different web page into a “div” on the existing page. So you layout, make, and create the nice looking popup form as a separate web page. jQuery is able to remove the “form” and additonal tags out of that page load, and then inject it into the existing page. (that code would be rather hard to re-produce). so jQuery.UI is able to pop up that separate page. however, the buttons on that loaded page (into that div) of course can't really run any code behind in the current page. However, the buttons CAN run local js in the current page. Thus the actions of this injected page would be local to each page. But the popup would not be directly calling a code behind stub.
Now, to adopt jQuery.UI, then you also have to of course adopt jQuery. So that is two extra libraries you need. (but, jQuery you likely already have).
However, I suppose the whole point of using the ajax toolkit is to avoid jQuery.ui in the first place. To be fair, before jQuery.ui came along, that tool kit was REALLY impressive, and gave asp.net folks a REAL leg up on the competition. (and it tends to be MUCH less wiring up then say using jQuery.UI
So the AjaxToolkit in its heyday was impressive. Now, it of course showing its age, but I still use the kit, and this is especially the case for the AjaxFileUploader. And yes I do use the popups – even to this day. However, I find now that jQuery.UI dialogs are more flexible, and would be better in this case (because you want a on-the fly setup).
Also, having code behind buttons in even the jQuery.UI dialog, or in this case the ajax popup? Well, only the action button can run code behind. The cancel button of course will just dismiss the dialog. However, any button in the dialog that WILL run code behind? Well, that's ok, since you have a page post back, and it actually the page postback that BLOWS out the dialog anyway.
I have an ASP.NET 4.5 web app that contains a form where the user can add some data and I have a button that I want to save the data in the database.
When the user presses this button, the first thing I do is search if there already exists a record for a specific item. If there is, I want to show a confirmation box where I'm letting the user know: "This record already exists. Do you want to update it?". If the user presses YES, I want to do an UPDATE, else I will do an INSERT. The problem is with this damn confirmation box.
What I have so far:
In aspx.cs:
public void OnConfirm(object sender, EventArgs e)
{
string confirmValue = Request.Form["confirm_value"];
if (confirmValue == "Yes")
{
Response.Write("YES");
}
else
{
Response.Write("NO");
}
}
In aspx I have:
<script>
function Confirm() {
var confirm_value = document.createElement("INPUT");
confirm_value.type = "hidden";
confirm_value.name = "confirm_value";
if (confirm("Record already exists. Do you want to update it?")) {
confirm_value.value = "Yes";
} else {
confirm_value.value = "No";
}
document.forms[0].appendChild(confirm_value);
}
</script>
and I added a button:
<asp:Button ID="alertBtn" runat="server" OnClientClick = "Confirm()" OnClick="OnConfirm" Text="" style="display:none"/>
If I remove the style and run the app, when I click on this button it works perfectly. The confirmation box shows up, when I click YES it calls a function, when I click NO it calls another function.
But how do I click on this button from code? Nothing works!
I tried with:
1) alertBtn.Click += new EventHandler(this.OnConfirm);// doesn't do anything
2) ScriptManager.RegisterStartupScript(this.Page, Page.GetType(), "somekey", "Confirm();", true);// I was only able to run the Confirm() method, but it didn't call the OnConfirm method which is on the server.
3) Following step 2, I tried adding a call from js to c# in the Confirm() method: document.getElementById('<%=alertBtn%>).OnClick // this didn't work either
So I just want to do a Button.Click from code behind in order to trigger the Confirm() method which will open a confirmation box and after I click YES/NO, the OnConfirm method from the server should call the appropriate function based on this YES/NO value. If you have another solution besides the one with using a button, I'm open to new ideas.
Update
To better explain my problem, I added this demo link. I want to achieve the same thing without having to click on a button, just from code.
Basically we have the "illusion" of an notification message box that exists as .Visible = false in the MasterPage. When it comes time to display a message in the box, we run a method that looks like this:
public static void DisplayNotificationMessage(MasterPage master, string message)
{
if (Master.FindControl("divmsgpanel") != null)
{
master.FindControl("divmsgpanel").Visible = true;
}
if (master.FindControl("divdimmer") != null)
{
master.FindControl("divdimmer").Visible = true;
}
TextBox thetxtbox = (TextBox)master.FindControl("txtboxmsgcontents");
if (thetxtbox != null)
{
thetxtbox.Text = message;
}
}
Basically through our designers awesome CSS voodoo, we end up with what appears to be a floating message box as the rest of the page appears dimmed out. This message box has a "Close" button to dismiss the "popup" and restore the dimmer, returning the site to the "normal" visual state. We accomplish this with JavaScript in the MasterPage:
function HideMessage() {
document.getElementById("<%# divmsgpanel.ClientID %>").style.display = 'none';
document.getElementById("<%# divdimmer.ClientID %>").style.display = 'none';
return false;
}
and the button's declaration in the .aspx page calls this HideMessage() function OnClientClick:
<asp:Button ID="btnmsgcloser" runat="server" Text="Close" style="margin: 5px;"
OnClientClick="return HideMessage()" />
The problem:
All future postbacks cause the MasterPage to "remember" the state of those divs from how they were before the HideMessage() JavaScript was executed. So in other words, every single postback after the initial call of the DisplayNotificationMessage() method causes the page to return to divmsgpanel.Visible = true and divdimmer.Visible = true, creating an endlessly annoying message box that incorrectly pops up on every postback.
The question:
Since we want the Close function to stay client-side JavaScript, how can we "notify" the page to stop reverting to the old state on postback, for just these two divs?
Can you try setting them to Visible = false in Master_Page Load event? It should hide them and reshow them just when you call DisplayNotificationMessage
I am using this javascript function to show different popups if location count varies. Here the txthiddenloccount value is null if the txtbox's visibility is false. If the visibility is true, it works fine. What strange is this??? Can someone help me out.
function isPageValid()
{
var validated = Page_ClientValidate('groupProfile');
var loccount = document.getElementById("ctl00_ContentPlaceHolder1_txthiddenloccount").value;
if(validated)
{
if(loccount == '1')
{
var mdlPopup = $find('<%= ModalPopupExtendersavechanges.ClientID %>');
if(mdlPopup)
{
mdlPopup.show();
}
}
else
{
var mdlPopup = $find('<%= ModalPopupExtenderMerchantUpdate.ClientID %>');
if(mdlPopup)
{
mdlPopup.show();
}
}
}
}
if txthiddenloccount is an asp:TextBox that has the Visible property set to false then it does not exist on the page that is readable by javascript. It will be stored in the ViewState.
For something like this you're probably better off using an asp:HiddenField and setting the value, that will create an input type='hidden' that will be accessible through javascript.
Here you are trying to get txthiddenloccount control's value which hasn't rendered on the page because its visibility is false.
so first you have to check if it is null i.e you can write code like this.
var loccount='';
if(document.getElementById("ctl00_ContentPlaceHolder1_txthiddenloccount") != null)
{
loccount = document.getElementById("ctl00_ContentPlaceHolder1_txthiddenloccount").value;
}
If the Visible property of the control is set as false via ASP.NET, it will be part of the control tree but will never actually get rendered to the page. If it doesn't get rendered to the page, JavaScript can't access it.
If you want to hide it using ASP.NET, you could do it this way in C#...
txthiddenloccount.Style.Add("display", "none");
That will not prevent the control from rendering on the page AND it will use CSS to hide it. Alternatively, you could do this, but it might not be what you want, visually...
txthiddenloccount.Style.Add("visibility", "hidden");
Hope that helps.
I have an ASP.Net user control that contains some checkboxes, and I want to use JQuery to raise an event from the user control when one of the checkboxes is clicked. Here is the JQuery code in the user control where I'm trying to raise the event:
$(document).ready(function() {
$(':checkbox').click(function(){
$('#hfRemainingInstalls').trigger('CheckBoxClicked');
});
});
and here is the JQuery code in the containing aspx page where I'm trying to subscribe to the event:
$(document).ready(function() {
$("p").bind('CheckBoxClicked', function(e) {
alert("checkbox clicked");
});
});
I'm never seeing my alert when I click on one of the checkboxes. Anyone know what might be the problem here?
I am sure you have an ID problem. ASP.NET controls that reside inside of container elements such as UserControls and MasterPages, when rendered, have some junk prefixed to the id attribute to ensure uniqueness. It is usually something like "ctl01_01_YourID" That said, you should probably be using the jQuery endsWith selector...
$('input[id$=hfRemainingInstalls]').trigger('CheckBoxClicked');
The following will alert "true" if the element is found...
alert($('#hfRemainingInstalls').length > 0);
so is there a relationship between the Id tags P and Id hfRemainingInstalls
1: Solution
$(':checkbox').click(function(){
$("p").trigger('CheckBoxClicked');
});
$(document).ready(function() {
$("p").bind('CheckBoxClicked', function(e) {
alert("checkbox clicked");
});
});
2: Solution
$(':checkbox').click(function(){
$("#hfRemainingInstalls").trigger('CheckBoxClicked');
});
$(document).ready(function() {
$("#hfRemainingInstalls").bind('CheckBoxClicked', function(e) {
alert("checkbox clicked");
});
});