I have an asp button (the code is below). I have the event handler working, but I want to pass a string (which is the result of a javascript function) into the event handler function. Is there a way to do that?
<asp:Button runat="server" ID="Button1" OnClick="Button1_Click" Text="Run" />
Normally the way you would do this is to have you javascript modify an input control so that the value will be posted back with the Button click. If you want the user to visually not be able see the data that your javascript is modifying to post back then you can write it to a HiddenField.
You can use the OnClientClick to setup the javascript to run before the postback happens to ensure your modified value is put into the input control. Eg:
<asp:Button ID="yourButton" runat="server" Text="Click Me!"
OnClientClick="YourFunctionToAddStringToControl(); return true;"
OnClick="yourButton_Click" />
So you just need to swap the call to YourFunctionToAddStringToControl with your modified javascript function that is writing the value to a HiddenField or another input control. Then update your server side click handler to access the field.
Side Note: When using javascript to write to server side controls such as HiddenField, don't forget to use <%= yourHiddenField.ClientID %> to get the correct control name.
Not in the way you're asking.. However...
You CAN add an ASP:HiddenField, and use Javascript to modify the value of the HiddenField to be your string. Then you can access this in your Button Click event.
An example can be found here.
Related
I am displaying button on jquery page load event but it is not working. After the page is rendered, it is not visible.
It works fine if i set the visibility in code behind Page Load event.
Jquery
function pageLoad() {
$('#btnSwitchDistributor').css({ 'visibility': 'visible', 'display': 'inline-block' });
}
Html
<asp:Button ID="btnSwitchDistributor" runat="server" Text="Switch Distributor" Visible="false" />
According to MSDN, when you set Visible="false" in your server-side code then the element is not rendered to the client at all. Which means your button isn't "invisble" on the resulting page, it doesn't exist on the resulting page. No JavaScript code can interact with an element that isn't present.
It sounds like instead you want to apply a style to the control:
<asp:Button ID="btnSwitchDistributor" runat="server" Text="Switch Distributor" style="display:none;" />
Aside from that, there are two two potential issues here which I can't necessarily confirm from the content of the question, but which you'll want to check...
The ID value you're looking for is the server-side object's ID. This may not necessarily be the client-side id of the resulting HTML element. Examine the page source to see the client-side id. If it's different then you may need to set it explicitly using the ClientID property.
Do you ever call pageLoad() in your JavaScript code? If not then, well, you'd need to do that. I assume in the document.ready event handler? For jQuery that may be as simple as: $(pageLoad)
Just remove the visible html attribute and the JQuery css.
I'm writing an application in C#. I would like to replace the value for the TEXT property after the user clicks (focuses) on a textbox. I would like to set the TEXT value to be blank instead of the words "ENTER NAME HERE" when they click to edit the textbox.
Front-end:
<asp:TextBox Text="ENTER NAME HERE" OnClick="MyTextboxID_OnClick" ID="MyTextboxID" runat="server"></asp:TextBox>
Code-behind:
protected void MyTextboxID_OnClick(object sender, EventArgs e)
{
MyTextboxID.Text = "";
}
I tried to find the answer to this question but the answers didn't quite match what I wanted to do.
I was hoping C# had something similar to Javascript's "OnClick" or "OnFocus" events. I added the OnClick event to the textbox for illustration purposes. This OnClick event doesn't work.
Thank you in advance for your help!
Remember that ASP.NET is primarly server-side. Actions that run in C# require a post-back to the server. The impact of this on a page can be mitigated somewhat by using AJAX, but this is why you don't see an "OnClick" event off the ASP control.
However, you can still use the Javascript "OnClick" event. Since Javascript runs on the client, and the interaction in this instance is entirely handled on the client, you should just use that.
If you are not comfortable using Javascript, you might want to look at TextBoxWatermark server side control.
It is available NuGet.
<asp:TextBox OnClick="MyTextboxID_OnClick"
ID="MyTextboxID" runat="server">
</asp:TextBox>
<ajaxToolkit:TextBoxWatermarkExtender ID="TBWE2" runat="server"
TargetControlID="MyTextboxID"
WatermarkText="ENTER NAME HERE"
WatermarkCssClass="watermarked" />
You should simply use the following Placeholder="Enter text here."
Option One:
<asp:Textbox id="txtName" runat="server" placeholder="Enter name here." />
Option Two:
$("#<%= txtName.ClientId %>").setAttribute('placeholder', 'Enter name here.');
$("#<%= txtName.ClientId %>").attr('placeholder', 'Enter name here.');
For the Javascript implementation, you would simply place that in your View and wrap it in: <script type="text/javascript"></script>. Those are the ideal approaches to display text which clears on focus.
You could also utilize the Tooltip. Hopefully these examples assist you. Important note, I have no issues with compatibility in IE 8 with the Placeholder. Also these approaches won't force a Postback which can occur due to Server-Side. Which would force you to either do a Postback or implement a Update Panel / Ajax to hide the Postback.
Plugin: https://github.com/mathiasbynens/jquery-placeholder
Why don't you use the place holder attribute and not have to worry about replacing the text at all. This would show when the text box is empty but disappear on focus
protected void addSchoolButtonClick(object sender, ImageClickEventArgs e)
{
Page.ClientScript.RegisterStartupScript(GetType(), "MyKey1", "SchoolSearchPopUp();", true);
/*Some code*/
}
I am developing a website in asp.net.At a Hyperlink onclick event i want to call a javascript function"SchoolSearchPopUp()".this function is for creating a new popup window and it is working correctly.But my problem is ,a javascript function is calling or pop window opens only after executing the rest of the code in that function and that code need's some data that occurs as a result of popup.How can i create the popup before executing the rest of code in that function.
Change your postback trigger to something within the popup.
I don't think javascript can be called from code behind. C# is running from the server and java is all client side. There's a good explanation to a similar question here: http://forums.asp.net/t/1117189.aspx
If you need to execute a javascript function, you could try changing the hyperlink to a button and making use of the OnClientClick property. This executes script client side rather than calling a method on the server.
<asp:button id="Button1"
text="Click Here"
onclientclick="SchoolSearchPopUp()"
runat="server" />
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.button.onclientclick.aspx
You will need to write JavaScript on the page to handle the click of the button first and then call to the page method on the server.
Add an OnClientClick attribute to your button element and run your JavaScript method from there:
<asp:Button ID="TestButton" OnClientClick="SchoolSearchPopup()" Text="Click Me" OnClick="addSchoolButtonClick" runat="server"/>
<script type="text/javascript">
function SchoolSearchPopup()
{
alert("Popup");
}
</script>
If you want to execute some javascript before your postback you will need to register your hyperlink's click event to a js method, then submit your post to the server after performing whatever client side logic you are looking to run. (not the other way around, using RegisterStartupScript)
Example:
$("#myHyperLink").click(function() {
// do page logic, in your case show a modal window
$("#myModalDivContainer").show();
// submit your post to the server... replace targetClientID with ID of server control you're posting to
__doPostBack('targetClientID', '');
// NOTE: If you want to perform an AJAX request instead simply use some jQuery here instead. it's up to you how to handle the request from this point :)
});
Hope this helps!
In my asp.net web page, there are a few of buttons and checkboxs. They all can cause postback.
Can I detect which control is clicked? Because I will add code for if clicked a button then do something.
I saw that some examples are done with Jquery.
Can we just do it in C#?
Thanks.
Why are you not just using the click behavior of the button:
ASPX
<asp:Button id="Button1"
Text="Click here for greeting..."
OnClick="GreetingBtn_Click"
runat="server"/>
CS
void GreetingBtn_Click(Object sender,EventArgs e)
{
}
reference here
You could check Request.Form["_EVENTTARGET"] for the control that generated the postback
well if each of the buttons submit a key value to the post or get parameters, and theyre all different it should be pretty easy! :)
localhost/home.html?button=clicked&link=selected
the above is an example of a get parameter url, you can use jquery to get those, or if its a post you would have access to them in a similar way...the previous page would have to have been a form though.
You could eventually do it by checking Request.Form["_EVENTTARGET"] but that is highly unusual and certainly not necessary.
Whatever you need to do, you can do it in the Click event handler of the given control.
You can set a server hidden control specifying the action (checkbox/textbox/button clicked) using javascript & retrieve that server control in page load to check its action & add your code for that action
Im using asp.net c# (webforms)
I want to add a back button to my page. (you land on this page if you incorrectly fill in a form).
if javascript is enabled i want to go back via javascript, but if it is disabled i'll just do a response.redirect("~/home.aspx")...
how can i implement this? is it 2 buttons? how can i hide the other in the 2 different states if so.
thanks
<asp:Button OnClick="serverMethod" OnClientClick="return(jsMethod);" runat="server" ID="redirectButton" Text="Back" />
on the button, but set the OnClientCLick to:
return(javascriptredirect());
and the OnClick to your button click event handler in your code behind.
if javascript is enabled, it will do the javascript redirect, if not enabled the page will post back and you can do your OnClick code behind method whic can to the response.redirect. You can also return false from your function to prevent the postback from occurring such as the case with setting the OnClientClick="return(confirm('Are you sure?'));"
This link guides you how to do it http://aspadvice.com/blogs/azamsharp/archive/2007/09/30/Check-If-the-JavaScript-is-Enabled-on-the-Client_2700_s-Browser.aspx
Happy coding !!!!!!