{"id":20158,"date":"2022-11-08T22:06:32","date_gmt":"2022-11-08T16:36:32","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/"},"modified":"2022-11-08T22:06:32","modified_gmt":"2022-11-08T16:36:32","slug":"solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/","title":{"rendered":"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database"},"content":{"rendered":"

[ad_1]
\n<\/p>\n

\n
\n
<\/div>\n
\n
\n

You are doing quite a lot that is not necessary. I reduced the code and added some comments. In short:<\/p>\n

    \n
  1. Use the position<\/code> to find which data should be fetched (it could also be a prefetched list which would reduce the fetch from database to 1 query)<\/li>\n
  2. You should use the ViewHolder pattern to recycle and reuse views -> quite some performance improvement<\/li>\n
  3. You need to do “static” stuff outside the getView()<\/code> method because stuff like loading a Typeface is quite slow.<\/li>\n<\/ol>\n

    Hope the below code helps you!<\/p>\n

    public class RezeptArrayAdapter extends ArrayAdapter<String> {\n\n    public final Context context;\n    public final String[] values;\n    final DBHandler_Rezepte db_Rzpt;\n    \/\/TYPEFACE\/\/\/\/\/\/\/\/\/\/\/\n    Typeface tf;\n\n\n    public RezeptArrayAdapter(Context context, String[] values) {\n        super(context, R.layout.list_rezepte, values);\n        this.context = context;\n        this.values = values;\n\n        \/\/ Do \"static\/reusable\" stuff here\n        \/\/ DatenBank Abfrage Angepasst auf den Array \"context\" View\n        db_Rzpt = new DBHandler_Rezepte(context);\n        \/\/TYPEFACE\/\/\/\/\/\/\/\/\/\/\/\n        tf = Typeface.createFromAsset(context.getAssets(), \"fonts\/OFLGoudyStMTT.ttf\");\n    }\n\n    \/\/ will be called quite often! Make it fast as possible!\n    @Override\n    public View getView(int position, View convertView, ViewGroup parent) {\n        LayoutInflater inflater = (LayoutInflater) context\n                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);\n\n        \/\/Einzelabfrage der Datenbank Ratings damit Sie weiter unten verarbeitet werden k\u00f6nnen\n        ConDB_Rezepte data = db_Rzpt.getConDB_Rezepte(position);\n\n        \/\/ To not do too much at once this tip for later: Use the ViewHolder pattern\n        View rowView = inflater.inflate(R.layout.list_rezepte, parent, false);\n        TextView textView = (TextView) rowView.findViewById(R.id.label);\n        ImageView imageView = (ImageView) rowView.findViewById(R.id.logo);\n        RatingBar ratingbar1 = (RatingBar) rowView.findViewById(R.id.ratingBar1);\n\n        \/\/stellt ein das man die Ratingbar nicht clicken kann, somit bleibt die Steuerung erhalten. Sonst ist die Liste nicht mehr clickbar\n        ratingbar1.setIsIndicator(true);\n\n        textView.setText(values[position]);\n\n        textView.setTypeface(tf);\n\n\n        \/\/ Change icon based on name\n        String pos = values[position];\n\n        \/\/ data should contain the information which icon should be shown!\n        \/\/int KuchenIcon = R.drawable.ic_kuchen;\n        \/\/int MuffinIcon = R.drawable.ic_muffin;\n        \/\/int PlaetzchenIcon = R.drawable.ic_plaetzchen;\n        \/\/int ApfelkandiertIcon = R.drawable.ic_apfelkandiert;\n        \/\/int OthersIcon = R.drawable.ic_others;\n\n        \/\/ apply values\/data to the view\n        imageView.setImageResource(data.getIcon());\n        ratingbar1.setRating(data.getrating());\n\n        return rowView;\n    }\n\n}\n<\/code><\/pre>\n
    Update:<\/p>\n
    For the problem with the icon, the solution might be pretty easy: You can get the icon by name. All you need to do is storing the name of the icon in the database.<\/p>\n
    When you have done that, you can use the following method to load the drawables:<\/p>\n
    public int getDrawableResource(String drawableName){\n    return getResources().getIdentifier(drawableName, \"drawable\", getActivity().getPackageName());\n}\n<\/code><\/pre>\n
    So all you need is to store the icon name in the database so that data.getIcon() returns the resource id you get by using the above method.<\/p>\n<\/p><\/div>\n
    <\/div>\n<\/div>\n
                6<\/span> <\/p><\/div>\n<\/div>\n
    [ad_2]<\/p>\n
    solved Bad performance of custom Listview, Listview Items Name gets converted from Database <\/p>\n","protected":false},"excerpt":{"rendered":"
    [ad_1] You are doing quite a lot that is not necessary. I reduced the code and added some comments. In short: Use the position to find which data should be fetched (it could also be a prefetched list which would reduce the fetch from database to 1 query) You should use the ViewHolder pattern to … 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-20158","post","type-post","status-publish","format-standard","hentry","category-solved","tag-android","tag-java"],"yoast_head":"\n[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database - 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-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] You are doing quite a lot that is not necessary. I reduced the code and added some comments. In short: Use the position to find which data should be fetched (it could also be a prefetched list which would reduce the fetch from database to 1 query) You should use the ViewHolder pattern to ... Read more\" \/>\n<meta property=\"og:url\" content=\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/\" \/>\n<meta property=\"og:site_name\" content=\"JassWeb\" \/>\n<meta property=\"article:published_time\" content=\"2022-11-08T16:36:32+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=\"2 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/\"},\"author\":{\"name\":\"Kirat\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31\"},\"headline\":\"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database\",\"datePublished\":\"2022-11-08T16:36:32+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/\"},\"wordCount\":192,\"publisher\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\"},\"keywords\":[\"android\",\"java\"],\"articleSection\":[\"Solved\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/\",\"url\":\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/\",\"name\":\"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database - JassWeb\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#website\"},\"datePublished\":\"2022-11-08T16:36:32+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/jassweb.com\/solved\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database\"}]},{\"@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=1775798750\",\"contentUrl\":\"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1775798750\",\"caption\":\"Kirat\"},\"sameAs\":[\"http:\/\/jassweb.com\"],\"url\":\"https:\/\/jassweb.com\/solved\/author\/jaspritsinghghumangmail-com\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database - 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-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/","og_locale":"en_US","og_type":"article","og_title":"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database - JassWeb","og_description":"[ad_1] You are doing quite a lot that is not necessary. I reduced the code and added some comments. In short: Use the position to find which data should be fetched (it could also be a prefetched list which would reduce the fetch from database to 1 query) You should use the ViewHolder pattern to ... Read more","og_url":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/","og_site_name":"JassWeb","article_published_time":"2022-11-08T16:36:32+00:00","author":"Kirat","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Kirat","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/#article","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/"},"author":{"name":"Kirat","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31"},"headline":"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database","datePublished":"2022-11-08T16:36:32+00:00","mainEntityOfPage":{"@id":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/"},"wordCount":192,"publisher":{"@id":"https:\/\/jassweb.com\/solved\/#organization"},"keywords":["android","java"],"articleSection":["Solved"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/","url":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/","name":"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database - JassWeb","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/#website"},"datePublished":"2022-11-08T16:36:32+00:00","breadcrumb":{"@id":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/jassweb.com\/solved\/solved-bad-performance-of-custom-listview-listview-items-name-gets-converted-from-database\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/jassweb.com\/solved\/"},{"@type":"ListItem","position":2,"name":"[Solved] Bad performance of custom Listview, Listview Items Name gets converted from Database"}]},{"@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=1775798750","contentUrl":"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1775798750","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\/20158","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=20158"}],"version-history":[{"count":0,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts\/20158\/revisions"}],"wp:attachment":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/media?parent=20158"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/categories?post=20158"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/tags?post=20158"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}