{"id":25552,"date":"2022-12-11T00:59:03","date_gmt":"2022-12-10T19:29:03","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-android-onclick-and-onclicklistner\/"},"modified":"2022-12-11T00:59:03","modified_gmt":"2022-12-10T19:29:03","slug":"solved-android-onclick-and-onclicklistner","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-android-onclick-and-onclicklistner\/","title":{"rendered":"[Solved] Android OnClick and OnclickListner"},"content":{"rendered":"<p> [ad_1]<br \/>\n<\/p>\n<div id=\"answer-45184052\" class=\"answer js-answer accepted-answer js-accepted-answer\" data-answerid=\"45184052\" data-parentid=\"45183851\" 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>Why don&#8217;t you make <code>mNsdUtils<\/code> to be a member field if it should be accessed from the outside of the function?<\/p>\n<p>The root cause saying <code>mNsdUtils<\/code> is null from the <code>MainActivity.onClickDiscover()<\/code> implementation. <\/p>\n<p>Implement in the method itself, as the context is different throwing a null pointer exception.<\/p>\n<p>A small tip for you: read the stack trace and find your source code(for your case, MainActivity.java) to locate what was the first error from bottom to up.<\/p>\n<pre><code>Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.example.android.implicitintents.Utils.NsdUtils.discoverServices()' on a null object reference\n  at com.example.android.implicitintents.MainActivity.onClickDiscoverAura(MainActivity.java:40)\n  at java.lang.reflect.Method.invoke(Native Method) \n  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) \n  at android.view.View.performClick(View.java:5637) \n  at android.view.View$PerformClick.run(View.java:22429) \n  at android.os.Handler.handleCallback(Handler.java:751) \n  at android.os.Handler.dispatchMessage(Handler.java:95) \n  at android.os.Looper.loop(Looper.java:154) \n  at android.app.ActivityThread.main(ActivityThread.java:6119) \n  at java.lang.reflect.Method.invoke(Native Method) \n  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) \n  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) \n<\/code><\/pre>\n<p>This is the one you need. <\/p>\n<p><code>at com.example.android.implicitintents.MainActivity.onClickDiscoverAura(MainActivity.java:40)<\/code><\/p>\n<\/p><\/div>\n<div class=\"mt24\"><\/div>\n<\/div>\n<p>            <span class=\"d-none\" itemprop=\"commentCount\">1<\/span> <\/p><\/div>\n<\/div>\n<p>[ad_2]<\/p>\n<p>solved Android OnClick and OnclickListner <\/p>\n","protected":false},"excerpt":{"rendered":"<p>[ad_1] Why don&#8217;t you make mNsdUtils to be a member field if it should be accessed from the outside of the function? The root cause saying mNsdUtils is null from the MainActivity.onClickDiscover() implementation. Implement in the method itself, as the context is different throwing a null pointer exception. A small tip for you: read the &#8230; <a title=\"[Solved] Android OnClick and OnclickListner\" class=\"read-more\" href=\"https:\/\/jassweb.com\/solved\/solved-android-onclick-and-onclicklistner\/\" aria-label=\"More on [Solved] Android OnClick and OnclickListner\">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":[452,323],"class_list":["post-25552","post","type-post","status-publish","format-standard","hentry","category-solved","tag-android","tag-java"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v26.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>[Solved] Android OnClick and OnclickListner - 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-android-onclick-and-onclicklistner\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] Android OnClick and OnclickListner - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] Why don&#8217;t you make mNsdUtils to be a member field if it should be accessed from the outside of the function? 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