Develop Reference

How to prevent postback on asp button while displaying a popup using JQuery

I have the following ItemTemplate in my GridView:
<ItemTemplate>
<asp:Button UseSubmitBehavior="false" runat="server" ID="btnShow" CssClass="btnSearch" Text="View All" CommandName="ViewAll" OnClientClick="myfunction(); return false;" OnCommand="btnShow_Command" CommandArgument='<%#((GridViewRow)Container).RowIndex%>' />
</ItemTemplate>
For the ItemTemplate I have a button which opens a popup window when clicked by using the following JQuery:
$(document).ready(function () {
$(".btnSearch").click(function (e) {
e.preventDefault();
//centering with css
centerPopup();
//load popup
loadPopup();
});
});
function myfunction() {
}
my Command code-behind:
protected void btnShow_Command(object sender, CommandEventArgs e)
{
int index = 0;
if (e.CommandName == "ViewAll")
{
index = Convert.ToInt32(e.CommandArgument);
DataTable cacheTable = HttpContext.Current.Cache["ResultsTable"] as DataTable;
string column = cacheTable.Rows[index].Field<string>("Guideline");
string test = BookingResults.Rows[index].Cells[7].Text;
string html = HttpUtility.HtmlDecode(column);
ResultsDiv.InnerHtml = html;
//tbGL.Text = html;
//upData.Update();
//MessageBox.Show(index.ToString());
}
}
I added the OnClientClick="myfunction(); return false;" because it was doing a postback each time I clicked. If I have multiple rows, it only works the first time I click but any time after, the popup is not displayed when another or the same button is clicked.
How do I resolve it so no matter which button is clicked the popup is displayed without doing a postback?

Actually you have not showed up the implementation of your method myfunction(), in case the myfunction() method have any syntactical error then the OnClientClick event will be void and it will post-back/submit the form to the server.
Try to remove the call from OnClientClick and just implement your logic at jquery on click event by using class selector as follows
$(document).ready(function () {
$(".btnSearch").click(function (e) {
e.preventDefault();
alert($(this).val() + " Clicked"); // you can put your method mymethod() here
// you can put youe popup logic here
return false;
});
});
You can also see this example of js fiddle

Put it out on the tag or <%: Html.BeginForm %> tag

OnClientClick="return myfunction();
function myfunction(){
// you can put youe popup logic here
return false;
}
Using like this your button never do post back.

ASP disable button during postback

I have a button which i am trying to add a css class to appear disabled once the user has clicked it.
protected void Button_Continue_OnClick(object sender, EventArgs e)
{
Panel_Error.Visible = false;
Literal_Error.Text = "";
if (RadioButton_Yes.Checked)
{
...//if radio checked get text and process etc.
}
}
My button onlick is above which simply processes a textbox filled on the page.
My button looks like this:
<asp:Button runat="server" ID="Button_Continue" CssClass="button dis small" Text="Continue" OnClick="Button_Continue_OnClick" ClientIDMode="Static" OnClientClick="return preventMult();" />
And my javscript is as follows:
<script type="text/javascript">
var isSubmitted = false;
function preventMult() {
if (isSubmitted == false) {
$('#Button_Continue').removeClass('ready');
$('#Button_Continue').addClass('disabled');
isSubmitted = true;
return true;
}
else {
return false;
}
}
</script>
The problem I am having is that the css class added works fine on the first postback, but after which my button onclick doesnt work and the button cant be clicked again if the user needs to resubmit the data if it is wrong
Another problem I am having is that with a breakpoint in my method i notice that the method is fired twice on the click.

Looks like you need something like this:
private void Page_Load()
{
if (!IsPostBack)
{
//doNothing
}
else
{
//button.disabled = true
}
}

try this
<asp:Button runat="server" ID="Button_Continue" AutoPostBack="true" CssClass="button dis small" Text="Continue" OnClick="Button_Continue_OnClick" ClientIDMode="Static" OnClientClick="return preventMult();" />

No response when call button click in javascript

Good day,
I have a aspx contain a button with ID button1, the following is my aspx code :
<div>
<asp:LinkButton ID="lnkView" CommandName="VIEW" runat="server">View</asp:LinkButton>
<asp:Button ID="button1" runat="server" Text="OK" onclick="button1_Click" />
</div>
/*
some code here
*/
<script>
function test()
{
document.getElementById("<%=button1.ClientID %>").click();
alert("hello");
return true;
}
</script>
The following is my aspx code behind:
//some code here
lnkView.Attributes.Add("onclick", "return test()");
//some code here
protected void button1_Click(object sender, EventArgs e)
{
ScriptManager.RegisterStartupScript(this.Page, this.GetType(), "Javascript", "<script>alert('Record Added Successfully')</script>", false);
}
As you can see, my linkView link button have a javascript function test() when click on it.
I can alert the "Record Added Successfully" by click on the Button1.
However, when I click on linkView link button, the "Record Added Successfully" didnt alert, it only alert "Hello".
I think I am missunderstand in some programming concept.
Kindly advise.
Thanks.

This will trigger the event in code behind.
Try this in your .aspx page:
//Code:
<script type="text/javascript">
function test(parameter)
{
__doPostBack('button1_Click', parameter)
}
</script>

You can fix this by returning false instead of true as the result of the function test(). This way you will cancel default behavior of the link with ID lnkView ie sending form

Using OnClick event with PostBackUrl attribute of asp:Button

I have an asp:Button control like this;
<asp:Button ID="btnPayCC" CssClass="paymentButton" runat="server" Text="ONAYLA"
OnClientClick="if(!doPostBack()) return false; frmMaster.target='_blank'"
PostBackUrl="http://www.google.com" OnClick="btnPayCC_Click" />
And doPostBack javascript function is;
function doPostBack()
{
__doPostBack('<%= btnPayCC.ClientID %>', '');
return true;
};
When I clicked the button, then it opens new page(google.com) as I wish,
But do not postback into button control's OnClick event.
What is the problem?
How can I solve it?

I had the same problem. I solved it by adding a Response.Redirect("url") at the end of my onClick event for the Button and removing the PostbackUrl attribute from the button so that is uses autopostback to the same url. IE:
protected void Button_Click(object sender, EventArgs e)
{
//do your button click events here
Response.Redirect("~/url.aspx");
}
and
<asp:Button ID="Button" runat="server" CausesValidation="false" OnClick="Button_Click">

How to validate a form in ASP.NET using an image button, before raising the onClick event?

This may be a silly question but i'm a beginer here..
I created a form in asp.net and it's all fields are validated using validation controls on clicking an image button.It is working properly.After that i add an event to the button.This is the code of that button.
<asp:ImageButton ID="Submit" runat="server" OnClick="submit_Clicked" ValidationGroup="AddSchoolValidationGroup" CausesValidation="true" ImageUrl="~/Styles/images/submit-btn.png" OnClientClick="submitClicked" />
The purpose of that event is for submitting all the values in the form to database.Here my problem is,After adding the onClick event to button, validation has not taken place.And i want these onClick event to raise only when the form is validated successfully.Can any one guide me ..Thanks in Advance.

make sure that you are using the same validation group for all the validation controls.
in addition you can use OnClientClick event to call validation.
<asp:ImageButton ID="Submit" runat="server" OnClick="submit_Clicked" ValidationGroup="AddSchoolValidationGroup" CausesValidation="true" ImageUrl="~/Styles/images/submit-btn.png" OnClientClick="return Page_ClientValidate('AddSchoolValidationGroup');" />

You need to validate the page before submitting. Please add attribute for button.
protected void Page_Load(object sender, EventArgs e)
{
Submit.Attributes.Add("onclick", "javascript:if(Page_ClientValidate('AddSchoolValidationGroup')){return true;}else{return false;}");
}
Since you have a method "submitClicked" in onclient click, you can call the same inside Page_ClientValidate and remove the existing "OnClientClick" property.
protected void Page_Load(object sender, EventArgs e)
{
Submit.Attributes.Add("onclick", "javascript:if(Page_ClientValidate('AddSchoolValidationGroup')){submitClicked(); return true;}else{return false;}");
}

You can use javascript function
function validateForm() {
if (document.getElementById('txtName').value == '')
{
ValidatorEnable(document.getElementById("rfvName"), true) // rfvName is id of validator
return false; }
}
and call that function on client click of image button
<asp:ImageButton ID="Submit" runat="server" OnClientClick="validateForm();" OnClick="submit_Clicked" ValidationGroup="AddSchoolValidationGroup" CausesValidation="true" ImageUrl="~/Styles/images/submit-btn.png" />

Replace OnClientClick="submitClicked" with OnClientClick="return submitClicked();"
function submitClicked()
{
if (document.getElementById('txtname') != '') {
return true;
}
else {
alert('Please Enter Name');
return false;
}
}
So until all the validations are validated, the Server side event will not be called.