{"id":8901,"date":"2022-09-16T04:36:35","date_gmt":"2022-09-15T23:06:35","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/"},"modified":"2022-09-16T04:36:35","modified_gmt":"2022-09-15T23:06:35","slug":"solved-asp-net-null-reference-exception-due-to-not-finding-controls","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/","title":{"rendered":"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls"},"content":{"rendered":"<p> [ad_1]<br \/>\n<\/p>\n<div id=\"answer-32337853\" class=\"answer js-answer accepted-answer js-accepted-answer\" data-answerid=\"32337853\" data-parentid=\"32336713\" data-score=\"1\" data-position-on-page=\"1\" data-highest-scored=\"1\" data-question-has-accepted-highest-score=\"1\" itemprop=\"acceptedAnswer\" itemscope itemtype=\"https:\/\/schema.org\/Answer\">\n<div class=\"post-layout\">\n<div class=\"votecell post-layout--left\"><\/div>\n<div class=\"answercell post-layout--right\">\n<div class=\"s-prose js-post-body\" itemprop=\"text\">\n<p>In my experience, DIV&#8217;s are not registered to the server like ASP controls are so calling them directly would produce bad results. When making changes to the controls, i.e. adding styles, make sure you tell ASP what kind of control you have.<\/p>\n<p>For example:<\/p>\n<pre><code>HtmlGenericControl _fail = (HtmlGenericControl)Page.FindControl(\"fail\");\n\n_fail.Style.Item(\"visibility\") = \"hidden\";\n<\/code><\/pre>\n<p>Edit: The problem lies with the ContentPlaceHolder being nested in the LoginView. Drilling down to the controls should expose them.<\/p>\n<p>Example:<\/p>\n<pre><code>LoginView temp = (LoginView)this.Master.FindControl(\"LoginView1\");\nContentPlaceHolder tempp = (ContentPlaceHolder)temp.FindControl(\"MainContent\");\nHtmlGenericControl _fail = (HtmlGenericControl)tempp.FindControl(\"fail\");\n<\/code><\/pre>\n<p>If you create some class variables to point to these controls and assign them on page load, you can then call them from wherever you want in your code.<\/p>\n<p>To add further confusion to the solution, if you only add: <\/p>\n<pre><code>LoginView temp = (LoginView)this.Master.FindControl(\"LoginView1\");\nContentPlaceHolder tempp = (ContentPlaceHolder)temp.FindControl(\"MainContent\");\n<\/code><\/pre>\n<p>to Page_Load and nothing else, it exposes the controls so you can call fail.Style.Add(&#8220;visibility&#8221;, &#8220;hidden&#8221;) directly. There seems to be some delay as to when the controls are enumerated by ASP. Calling FindControls() on LoginView, appears to refresh the control &#8220;cache&#8221; exposing the controls as you would expect them to be.<\/p>\n<\/p><\/div>\n<div class=\"mt24\"><\/div>\n<\/div>\n<p>            <span class=\"d-none\" itemprop=\"commentCount\">6<\/span> <\/p><\/div>\n<\/div>\n<p>[ad_2]<\/p>\n<p>solved ASP.net Null Reference Exception Due to Not Finding Controls <\/p>\n","protected":false},"excerpt":{"rendered":"<p>[ad_1] In my experience, DIV&#8217;s are not registered to the server like ASP controls are so calling them directly would produce bad results. When making changes to the controls, i.e. adding styles, make sure you tell ASP what kind of control you have. For example: HtmlGenericControl _fail = (HtmlGenericControl)Page.FindControl(&#8220;fail&#8221;); _fail.Style.Item(&#8220;visibility&#8221;) = &#8220;hidden&#8221;; Edit: The problem &#8230; <a title=\"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls\" class=\"read-more\" href=\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\" aria-label=\"More on [Solved] ASP.net Null Reference Exception Due to Not Finding Controls\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[320],"tags":[751,324,355,2504],"class_list":["post-8901","post","type-post","status-publish","format-standard","hentry","category-solved","tag-asp-net","tag-c","tag-nullreferenceexception","tag-web-controls"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v26.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>[Solved] ASP.net Null Reference Exception Due to Not Finding Controls - JassWeb<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] In my experience, DIV&#8217;s are not registered to the server like ASP controls are so calling them directly would produce bad results. When making changes to the controls, i.e. adding styles, make sure you tell ASP what kind of control you have. For example: HtmlGenericControl _fail = (HtmlGenericControl)Page.FindControl(&quot;fail&quot;); _fail.Style.Item(&quot;visibility&quot;) = &quot;hidden&quot;; Edit: The problem ... Read more\" \/>\n<meta property=\"og:url\" content=\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\" \/>\n<meta property=\"og:site_name\" content=\"JassWeb\" \/>\n<meta property=\"article:published_time\" content=\"2022-09-15T23:06:35+00:00\" \/>\n<meta name=\"author\" content=\"Kirat\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Kirat\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\"},\"author\":{\"name\":\"Kirat\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31\"},\"headline\":\"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls\",\"datePublished\":\"2022-09-15T23:06:35+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\"},\"wordCount\":186,\"publisher\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\"},\"keywords\":[\"asp.net\",\"c++\",\"nullreferenceexception\",\"web-controls\"],\"articleSection\":[\"Solved\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\",\"url\":\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\",\"name\":\"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls - JassWeb\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#website\"},\"datePublished\":\"2022-09-15T23:06:35+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/jassweb.com\/solved\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/jassweb.com\/solved\/#website\",\"url\":\"https:\/\/jassweb.com\/solved\/\",\"name\":\"JassWeb\",\"description\":\"Build High-quality Websites\",\"publisher\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/jassweb.com\/solved\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\",\"name\":\"Jass Web\",\"url\":\"https:\/\/jassweb.com\/solved\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png\",\"contentUrl\":\"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png\",\"width\":693,\"height\":132,\"caption\":\"Jass Web\"},\"image\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31\",\"name\":\"Kirat\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586\",\"contentUrl\":\"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586\",\"caption\":\"Kirat\"},\"sameAs\":[\"http:\/\/jassweb.com\"],\"url\":\"https:\/\/jassweb.com\/solved\/author\/jaspritsinghghumangmail-com\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls - JassWeb","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/","og_locale":"en_US","og_type":"article","og_title":"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls - JassWeb","og_description":"[ad_1] In my experience, DIV&#8217;s are not registered to the server like ASP controls are so calling them directly would produce bad results. When making changes to the controls, i.e. adding styles, make sure you tell ASP what kind of control you have. For example: HtmlGenericControl _fail = (HtmlGenericControl)Page.FindControl(\"fail\"); _fail.Style.Item(\"visibility\") = \"hidden\"; Edit: The problem ... Read more","og_url":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/","og_site_name":"JassWeb","article_published_time":"2022-09-15T23:06:35+00:00","author":"Kirat","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Kirat","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/#article","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/"},"author":{"name":"Kirat","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31"},"headline":"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls","datePublished":"2022-09-15T23:06:35+00:00","mainEntityOfPage":{"@id":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/"},"wordCount":186,"publisher":{"@id":"https:\/\/jassweb.com\/solved\/#organization"},"keywords":["asp.net","c++","nullreferenceexception","web-controls"],"articleSection":["Solved"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/","url":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/","name":"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls - JassWeb","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/#website"},"datePublished":"2022-09-15T23:06:35+00:00","breadcrumb":{"@id":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/jassweb.com\/solved\/solved-asp-net-null-reference-exception-due-to-not-finding-controls\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/jassweb.com\/solved\/"},{"@type":"ListItem","position":2,"name":"[Solved] ASP.net Null Reference Exception Due to Not Finding Controls"}]},{"@type":"WebSite","@id":"https:\/\/jassweb.com\/solved\/#website","url":"https:\/\/jassweb.com\/solved\/","name":"JassWeb","description":"Build High-quality Websites","publisher":{"@id":"https:\/\/jassweb.com\/solved\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/jassweb.com\/solved\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/jassweb.com\/solved\/#organization","name":"Jass Web","url":"https:\/\/jassweb.com\/solved\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/","url":"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png","contentUrl":"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png","width":693,"height":132,"caption":"Jass Web"},"image":{"@id":"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31","name":"Kirat","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/image\/","url":"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586","contentUrl":"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586","caption":"Kirat"},"sameAs":["http:\/\/jassweb.com"],"url":"https:\/\/jassweb.com\/solved\/author\/jaspritsinghghumangmail-com\/"}]}},"_links":{"self":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts\/8901","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/comments?post=8901"}],"version-history":[{"count":0,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts\/8901\/revisions"}],"wp:attachment":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/media?parent=8901"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/categories?post=8901"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/tags?post=8901"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}