c# - Textbox (and other controls) - "Object not set to an instance...." -


i realize common error , i've followed many fixes problem offered online have yet find solution.

i developed winform app gets json external website. click button control , app goes through json serialiser method , posts results textbox , appends textarea. 

 public void renderdata(string buttontext)     {          if (buttontext == "start")         {             equationdata deserializeddata = getdata("http://test.ethorstat.com/test.ashx");              var processed = new processequation();             int result = processed.calculate(deserializeddata);              string res = deserializeddata.parm1 + "  " + deserializeddata.op + "  " + deserializeddata.parm2 +                 " = " + result;             textboxresult.text = res;              equation.append("  " + deserializeddata.parm1 + "  " + deserializeddata.op + "  " + deserializeddata.parm2 +                 " = " + result + '\n');             textarearesults.value = equation.tostring();         }     }

this worked fine was. requirements have changed in app has poll data every second. therefore created wcf web service called jquery script run every second.

the problem controls - textbox , textboxarea - generate {"object reference not set instance of object."}. assumption these controls aren't being loaded i'm calling method jquery's ajax function (?).

$(document).ready(function () {  //while ($('#ethorbutton').text != "stop") { if ($('#ethorbutton').click) {     $.ajax({     url: 'service/ethorservice.svc/getupdate',     method: 'get',     datatype: 'json',     success: function(){         alert("success");     },     error: function (err) {         alert(err);     }  }) //delay(1000);  }

});

my controls show in intellisense and, of course, on default.aspx when run it. how can fix this?

edit

i solved 'object not set...' problem instantiating new textbox:

 public partial class _default : page {     public static stringbuilder equation = new stringbuilder();     public textbox textboxtest = new textbox();

when debug , step through value set, textbox renders textbox empty. how fix that?

make method static , add annotation [webmethod] , return list of results. 

[system.web.services.webmethod(enablesession=true)] public static list<string> renderdata(string buttontext) {        // return result here }

pass parameter data:{buttontext:yourvalue} $.ajax call. , change success function , assign values control on client side via javascript.

success : function(msg){       if(msg.d!=null){              $('#<%=textboxresult.clientid%>').val(msg.d[0]); } }

Comments

Post a Comment

Popular posts from this blog

javascript - jQuery: Add class depending on URL in the best way -

i have html progress meter: <div class="col-md-3" style="margin-left: -20px;"> <div class="progress-pos active" id="progess-1"> <div class="progress-pos-inner"> login </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-2"> <div class="progress-pos-inner"> scan items </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-3"> <div class="progress-pos-inner"> confirm address </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-4"> <div class="progress-pos-in...
Read more

caching - How to check if a url path exists in the service worker cache -

i need check if particular url path exists in service worker cache. example, suppose url is: /myserviceworker/service?a=110&b=70 this url exists in cache, there many of them different values of , b. now, suppose want refresh of these urls, how can that? i want know how access key values service worker cache. if know key, plan follows: var url = new url(key); if(url.pathname === "\/myserviceworker/service") refetch key but not sure how cache key , in format is. mean, string or url? cache api has match() method returns promise resolving in response object if match or undefined if no match exists. second parameter object can specify ignoresearch not take account url parameters. the ignoresearch option supported firefox ( chrome status here ). in other hand, retrieve cache entries, can use keys() method.
Read more

Redirect to a HTTPS version using .htaccess -

i need modify .htaccess file redirect urls https version without "www". http://example.com --> https://example.com http://www.example.com --> https://example.com https://www.example.com --> https://example.com this how .htaccess file looks like: rewriteengine on rewritecond %{request_filename} !-d rewritecond %{request_filename} !-f rewriterule ^(.*)$ redirect.php?id=$1&page=$2 [qsa,l] what modifications need make .htaccess in order forward https without "www"? it depends on doing current code. looks file called redirect trying display php page seo friendly url. think might confusing people. anyway, need , force https without www, need 1 more rule above. also second rule needs two capture groups in rewriterule test string because wanting 2 different values using $1 , $2 references. rewriteengine on #rediect www non www and/or http https --- combinations. rewritecond %{http_host} !^example\.com [nc,or] rewritecond %{https} !^...
Read more