calling javascript from codebehind or dopastback in javascript - c#

i have a button1_click() function which runs on page load,,now i want to call this function from javascript,,for that purpose i need to do dopostback in javascript,,can nyone tell how can i do that..as u can see my pageload function that button1_click() runs on postback
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
int l = files.Length;
Button1.Attributes.Add("onclick", " alertMe("+ l.ToString() +");");
}
Button1_Click();
}
my javascript code :
function alertMe(len)
{
if(len>3)
//do postback(post back will run Button1_click function)
else
alert('Hello');
}

This is a helpful link
From the article:
"
Calling postback event from Javascript
There may be some scenario where you may want to explicitly postback to the server using some clientside javascript. It is pretty simple to do this.
ASP.NET already creates a client side javascript method as shown below to support Postbacks for the web controls:
function __doPostBack(eventTarget, eventArgument) {
if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
theForm.__EVENTTARGET.value = eventTarget;
theForm.__EVENTARGUMENT.value = eventArgument;
theForm.submit();
}
}
"

one way would be to use an actual asp:Button and utilize the OnClientClick event...
<asp:Button id="myButton" runat="Server" OnClick="Button1_Click" OnClientClick="alertMe();" />
function alertMe()
{
if (this.len>3)
{
return true;
}
else
{
return false;
}
}
if alertMe returns true, the the postback to the server will occur, if it returns false,
it won't.
here is a link to more details on the OnClientClick event.

It looks like you want to use ajax to call this server method. You can use ajax.net to do this. Obviously as a result it will not be postback.
Have a look here for examples

Possibly this:
function alertMe(len)
{
if(len>3)
//do postback(post back will run Button1_click function)
alertMe(len);
else
alert('Hello');
}
I would always try to avoid inline js though

Related

Calling a function from behind in an aspx webpage

I have this hidden button that is linked to a function I would like to trigger automatically on the web page once the session has been timed out:
Button code:
<asp:Button runat="server" id ="btnHdn" Style="display: none" OnClick="Button1_Click"/>
Timeout session trigger:
setTimeout(function ()
{
document.getElementById("btnHdn").click;
}, timeout);
The code behind I would like to call (.cs):
protected void Button1_Click(object sender, EventArgs e)
{
RedirectToHomePage();
}
protected void RedirectToHomePage()
{
try
{
string whichCountry = ConfigurationManager.AppSettings["country"].ToString();
string isFromGMAL = ConfigurationManager.AppSettings["GMAL"].ToString();
string urlStr = "LanguageSelection.aspx";
if (whichCountry.ToLower() == "sg")
{
urlStr = "LandingPage.aspx";
}
else if (whichCountry.ToLower() == "nl")
{
urlStr = "LandingPagexxxx.aspx";
}
}
catch (System.Exception ex)
{
}
}
Apparently, the code does not seem to be working. Once the session has reached zero, nothing happened and the timer will keep continue on counting.
Would you guys please identify what is wrong with the code?
You just need to change little bit on JavaScript code cause btnHdn button ClientId is change on client side so use it like below and .click is a method so add brackets on it like .click()
setTimeout(function () {
document.getElementById("<%=btnHdn.ClientID%>").click();
}, timeout);

Continue executing an event after validations on modal or radwindow

I have the following scenario: A user makes a click on a button inside an asp page. Because of security reasons, during the click event execution the system determines that it is necessary to apply some validations before continuing with the execution of the fired event.
Those validations are shown in a window (in this case a Telerik RadWindow). Inside this RadWindow, there is a web user control (WUC) containg validations like a Captcha, or security code, secret questions, etc. After the user writes the captcha text or the necessary validations (it implies postbacks inside the WUC), the WUC should continue with the execution of the fired event from the botton which opened the RadWindow.
How can I do this? Any idea? Is it possible?
When you call your RadWindow, make sure the set the OnClientClose event. If you are creating your RadWindow from code-behind:
RadWindow newWindow = new RadWindow();
newWindow.OnClientClose = "onRadWindowClosed";
...
If you are opening your RadWindow through javascript, you can use the add_close() method:
...
getRadWindow().add_close('onRadWindowClosed');
...
In either case, you need to create a new event handler script on your calling page for the OnClientClose event:
function onRadWindowClosed(sender, eventArgs) {
var returnValue = eventArgs.get_argument();
if (returnValue != null) {
if (returnValue == "continue") {
// Continue doing work
}
else {
// Throw an error
}
}
}
On your WUC, in the btnContinue click event:
protected void btnContinue_Click(object sender, EventArgs e)
{
Page.ClientScript.RegisterClientScriptBlock(GetType(), "closeScript", "getRadWindow().close('continue');", true);
}
This function is used on both pages:
function getRadWindow() {
var oWindow = null;
if (window.radWindow)
oWindow = window.radWindow;
else if (window.frameElement.radWindow)
oWindow = window.frameElement.radWindow;
return oWindow;
}
UPDATE TO THE EXISTING ANSWER
On your calling page, add a function to get the RadAjaxManager (assuming you already have on the page. If not, you'll need one):
function get_ajaxManager() {
return $find("<%= Telerik.Web.UI.RadAjaxManager.GetCurrent(this.Page).ClientID %>");
}
Modify your OnClosed javascript function (from the calling page):
function onRadWindowClosed(sender, eventArgs) {
var returnValue = eventArgs.get_argument();
if (returnValue != null) {
if (returnValue == "continue") {
// This call will invoke a server side event
get_ajaxManager().ajaxRequest("continue~");
}
}
}
In your code-behind, handle the server-side event that gets called:
protected void RadAjaxManager1_Request(object source, Telerik.Web.UI.AjaxRequestEventArgs e)
{
try
{
if (e.Argument.Trim().Length == 0)
{
// Show a message when debugging, otherwise return
return;
}
string argument = (e.Argument);
String[] stringArray = argument.Split('~');
switch (stringArray[0])
{
case "continue":
// Continue performing your action or call a specific method
ServerSideMethodCall();
break;
}
}
catch (Exception ex)
{
RadAjaxManager.GetCurrent(this.Page).Alert("Unable to complete operation at this time: " + ex.Message);
}
}
As previously mentioned, you'll need a RadAjaxManager on the page if you don't already have one, and you'll need to tie the AjaxRequest handler to it.
<telerik:RadAjaxManager runat="server" ID="RadAjaxManager1" OnAjaxRequest="RadAjaxManager1_Request"></telerik:RadAjaxManager>
Sorry for the long-winded answer. Let me know if that gets you what you need.

How to call java script from C# code?

I have an Enable.js file that has an Enable() function. I want to call this Enable function from the C# codebehind. My .js file and c# file are in same application.
I have tried this, but it doesn't help me.
Page.ClientScript.RegisterStartupScript(this.GetType(), "click", "Enable(true)", true);
Try this:
ScriptManager.RegisterClientScriptInclude(
this,
typeof(Page),
"Enable-js",
ResolveClientUrl("~/scripts/Enable.js"));
ScriptManager.RegisterStartupScript(
this, GetType(), Guid.NewGuid().ToString(),
"Enable(True);", true);
http://msdn.microsoft.com/pt-br/library/bb337005.aspx
I could see "click" in your code. Hence, I assume that you need to click some button to call Enable(true) function inside Enable.js file
Follow these below steps:
Reference your Enable.js file inside <head> section like below.
<script src="Scripts/Enable.js" type="text/javascript"></script>
Enable.js file is given below:
function Enable(var){
alert(val)
}
To call on Enable() function on Button1's click event:
protected void Page_Load(object sender, EventArgs e){
Button1.Attributes.Add("OnClick", "return Enable('true');");
}
Let me know if you need some more help.
I wrote a nice little function for calling jquery or just general JS in C# based on some VB I saw a while ago.
public bool runJQueryCode(string message)
{
ScriptManager requestSM = ScriptManager.GetCurrent(Page);
if (requestSM != null && requestSM.IsInAsyncPostBack)
{
ScriptManager.RegisterClientScriptBlock(Page, typeof(Page), Guid.NewGuid().ToString(), getjQueryCode(message), true);
}
else
{
Page.ClientScript.RegisterClientScriptBlock(typeof(Page), Guid.NewGuid().ToString(), getjQueryCode(message), true);
}
return true;
}
private string getjQueryCode(string jsCodetoRun)
{
string x = "";
x += "$(document).ready(function() {";
x += jsCodetoRun;
x += " });";
return x;
}
So you can just call runJqueryCode("alert('hey')");
You are making a mistake here:
Page.ClientScript.RegisterStartupScript(this.GetType(), "click", "Enable(true)", true);
The Enable(true) is not possible its literal string true that you're trying to pass as parameter.
You should try this way, so it may help.Its only a sample for understanding
string func = "showSuccessMessage('"+name+"');";
//Pass string as funcion in c#
This Link will explain calling javascript function with parameter from C# Code behind.
this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "xx",
"<script>test("+x+","+y+");</script>");

button click event of code behind in javascript

i am trying to implement a button click event and trying to call it in my java script function without actually clicking the button.
protected void btn_hid_Click(object sender, EventArgs e) {
string fbid = tb_id.Text;
query = "select userid from users where fbid='" + fbid + "'";
ds = db.SelectDs(query);
}
now i want to call this function in javascript function as soon as page load occurs and java script is called.
function func() {
alert("hiden");
$(document).ready(function () {
control or simple html control
$("[id*='btn_hid']").click();
});
alert("hiden end");
}
but this is not happening.Could you please tell how to do it?
You can try with this code
btn_hid.Attributes.Add("onclick","return YourFunction()");
Nota : if your wish also register dynamically your script you can use
var script = "";
Page.RegisterStartupScript("YourkeyOfScript",script);
Nota : You can also use OnClientClick in your interface
Your code is right. but It may be some problem. you can try with the alternate code.
using the following line of code.
__doPostBack('<%= btn_hid.ClientID %>', '')

Callback function?

I need to callback Javascript function in my code, but not firing. I am providing details what I am doing?.
I have input button in the page that calling javascript function. There I am loading another ProfilePic.aspx page. ProfilePic.aspx has FileUpload, OK and cancle button
<input type=button value="Change Image" onclick="javascript:SelectUserImage()" />
Javascript functions are
<script type="text/javascript">
function SelectUserImageCallback(ret) {
var imgId = 'ctl00_PlaceHolderMain_prof_imgUser';
var clearId = 'ctl00_PlaceHolderMain_prof_hidImageURL';
if (ret) {
if (ret == '__RESET__') {
document.getElementById(imgId).src = '\u002f_layouts\u002fimages\u002fno_pic.gif';
document.getElementById('ctl00_PlaceHolderMain_prof_hidImageURL').value = '';
document.getElementById(clearId).style.display = 'none';
}
else {
document.getElementById(imgId).onload = 'imgResizeMax(\'ctl00_PlaceHolderMain_prof_imgUser\', 100);imgResizeTbl(\'ctl00_PlaceHolderMain_prof_imgUser\');';
document.getElementById(imgId).src = ret;
document.getElementById('ctl00_PlaceHolderMain_prof_hidImageURL').value = ret;
setTimeout('imgResizeMax(\'ctl00_PlaceHolderMain_prof_imgUser\', 100);imgResizeTbl(\'ctl00_PlaceHolderMain_prof_imgUser\');', 1);
setTimeout('imgResizeMax(\'ctl00_PlaceHolderMain_prof_imgUser\', 100);imgResizeTbl(\'ctl00_PlaceHolderMain_prof_imgUser\');', 100);
document.getElementById(clearId).style.display = '';
}
}
}
function SelectUserImage() {
var href = '\u002f_layouts\u002fProfilePic.aspx';
var features = 'resizable: yes; status: no; scroll: no; help: no; center: yes; dialogWidth: 460px; dialogHeight: 140px; width:460;height:240;menubar:no;directories:no;location:no;';
commonShowModalDialog(href, features, SelectUserImageCallback, null);
}
In the ProfilePic.aspx page once user click OK buttong. I am upload his pic with some logic then I am closing window with javascript
protected void btnOK_Click(Object sender, EventArgs e)
{
try
{
// My logic Here
Debug.WriteLine("Shared Pictures Save Ends: " + DateTime.Now);
Response.Write ("<script language =javascript>close();</script>");
Response.End();
}
catch (Exception exception)
{
LogMessage(exception.Message, EventLogEntryType.Error);
if (exception.Message.ToLower().Contains("blocked"))
errorDisplay.Text = "* This type of file has been blocked by the administrator, please try a different file.";
else
{
errorDisplay.Text = exception.Message;
}
}
}
My Question: I am able to close the window but, What ever I need to call callback function `SelectUserImageCallback' not firing. I need to call this method after OK button part execution done.
Are you closing the window before the callback executes? I've done that before. As an experiment, try commenting out the code that closes the window.
You may have to restructure your code so that the callback function closes the window when it's finished whatever it's doing.
Update: Sorry, I misunderstood the question. There was a lot of code and I didn't read it all. I thought the call back was in the dialog page, but it looks like it's in the main page. I'm not familiar with commonShowModalDialog(), but it looks like it may have something to do with SharePoint. Do you have any documentation on that method? I found this discussion that makes it look like there's a special way to return a value from the dialog box. It may be that your callback isn't being called because you're not closing the window the right way. (That's a total guess on my part.)
Good luck.

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