How to change value in array from asp.net to javascript

Question

I am loading the value of string myvalue (global string) in array arr in javascript by

function hello()
{
   alert("hi");
   var arr=[<% myvalue %>];
   alert(arr);
}

protected void ListBox1_SelectedIndexChanged(object sender, EventArgs e)
{
   myvalue="1234";
   Page.ClientScript.RegisterStartupScript(GetType(), "whatiskey", "hello();", true);  
}

and updating myvalue on listbox1.item select and calling method which updates value of arr, but javascript arr does not load the new value

score 1 · Answer 1 · answered Jan 20 '16 at 10:30

1

you have to put double quotes and write it like:

var arr=["<%=myvalue %>"];

or more better way :

var arr= new Array();
arr.push("<%=myvalue %>");

answered Jan 20 '16 at 10:30

Ehsan Sajjad

61,834
16
105
160

the problem is method is not being called , it is not showing any alert , how to solve it – phpnet Jan 20 '16 at 10:36
have a look on :http://stackoverflow.com/questions/4848678/how-to-call-javascript-function-from-code-behind – Ehsan Sajjad Jan 20 '16 at 10:38

Anil · Answer 2 · 2016-01-20T10:46:14.683

0

Register ListBox1 as partial post back element could also be one of the reason.

are you able debug, that ListBox1_SelectedIndexChanged is being called.

You need to something like below to stop this from multiple time registered, this can one of the reason not to call hello(). Use F12 to investigate the rendered HTML.

// Check to see if the client script is already registered.
    if (!Page.ClientScript.IsClientScriptBlockRegistered(cstype, csname2))
    {
           Page.ClientScript.RegisterStartupScript(GetType(), "aNewKey",  "hello();", true);  
    }

edited Jan 20 '16 at 10:46

answered Jan 20 '16 at 10:30

Anil

3,722
2
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49

The method hello() is not being executed , what is the problem here ? – phpnet Jan 20 '16 at 10:37
is ListBox1_SelectedIndexChanged executed, are you sure? – Anil Jan 20 '16 at 10:39

How to change value in array from asp.net to javascript

2 Answers2