{"id":704,"date":"2023-12-13T22:49:18","date_gmt":"2023-12-14T04:49:18","guid":{"rendered":"https:\/\/kop.lat\/blog\/?p=704"},"modified":"2023-12-13T22:49:18","modified_gmt":"2023-12-14T04:49:18","slug":"baseclass-command-class-in-a-mvvm-like-app-using-delegates-example-explanation","status":"publish","type":"post","link":"https:\/\/kop.lat\/blog\/baseclass-command-class-in-a-mvvm-like-app-using-delegates-example-explanation\/","title":{"rendered":"BaseClass Command class in a MVVM-like App using delegates example\/explanation"},"content":{"rendered":"\n<p><\/p>\n\n\n\n<div class=\"dm-code-snippet dark dm-normal-version default no-background-mobile\" snippet-height=\"\" style=\"background-color:#5E69FF\"><div class=\"control-language\"><div class=\"dm-buttons\"><div class=\"dm-buttons-left\"><div class=\"dm-button-snippet red-button\"><\/div><div class=\"dm-button-snippet orange-button\"><\/div><div class=\"dm-button-snippet green-button\"><\/div><\/div><div class=\"dm-buttons-right\"><a id=\"dm-copy-raw-code\"><span class=\"dm-copy-text\">Copy Code<\/span><span class=\"dm-copy-confirmed\" style=\"display:none\">Copied<\/span><span class=\"dm-error-message\" style=\"display:none\">Use a different Browser<\/span><\/a><\/div><\/div><pre class=\" line-numbers\"><code id=\"dm-code-raw\" class=\" no-wrap language-clike\">namespace crud2WSearch.Commands\n{\n    public class PopupCommand : ICommand\n    {\n        public event EventHandler? CanExecuteChanged;\n\n        private Action&lt;object> _Execute { get; set; }\n        private Predicate&lt;object> _CanExecute { get; set; }\n\n        public PopupCommand(Action&lt;object> ExecuteMethod, Predicate&lt;object> CanExecuteMethod)\n        {\n            _Execute = ExecuteMethod;\n            _CanExecute = CanExecuteMethod;\n        }\n\n        public bool CanExecute(object? parameter)\n        {\n            return _CanExecute(parameter);\n        }\n\n        public void Execute(object? parameter)\n        {\n            _Execute(parameter);\n        }\n    }\n}\n<\/code><\/pre><\/div><\/div>\n\n\n\n<p>This code defines a class named <strong><code>PopupCommand<\/code> <\/strong>that implements the <strong><code>ICommand<\/code> <\/strong>interface. <\/p>\n\n\n\n<p>The <code><strong>ICommand<\/strong><\/code> interface is commonly used in <strong>WPF <\/strong>and other <strong>XAML<\/strong>-based frameworks to represent a command that can be bound to user interface elements such as buttons. <\/p>\n\n\n\n<p>Explanation as follows:<\/p>\n\n\n\n<p>1. <strong><code>ICommand<\/code> Interface:<\/strong><\/p>\n\n\n\n<ul>\n<li>The <code>ICommand<\/code> interface provides a standard way to handle commands in a user interface. <\/li>\n\n\n\n<li>It includes the <code>CanExecute<\/code> and <code>Execute<\/code> methods, along with the <code>CanExecuteChanged<\/code> event.<\/li>\n<\/ul>\n\n\n\n<p>2. <strong><code>PopupCommand<\/code> Class:<\/strong><\/p>\n\n\n\n<ul>\n<li>The <code>PopupCommand<\/code> class implements the <code>ICommand<\/code> interface.<\/li>\n<\/ul>\n\n\n\n<p>3. <strong><code>CanExecuteChanged<\/code> Event:<\/strong><\/p>\n\n\n\n<ul>\n<li>This is an event of type <code>EventHandler<\/code> that is part of the <code>ICommand<\/code> interface. It is raised whenever the conditions for whether the command can execute (via the <code>CanExecute<\/code> method) may have changed. <\/li>\n\n\n\n<li>In this implementation, the event is nullable (<code>EventHandler?<\/code>) to indicate that it might be null.<\/li>\n<\/ul>\n\n\n\n<p>4. <strong>Private Properties:<\/strong><\/p>\n\n\n\n<ul>\n<li><code>_Execute<\/code> is a private property of type <code>Action&lt;object&gt;<\/code>. It represents the method to be executed when the command is invoked.<\/li>\n\n\n\n<li><code>_CanExecute<\/code> is a private property of type <code>Predicate&lt;object&gt;<\/code>. It represents the method that determines whether the command can execute in its current state.<\/li>\n<\/ul>\n\n\n\n<p>5. <strong>Constructor:<\/strong><\/p>\n\n\n\n<ul>\n<li>The constructor takes two parameters: <code>ExecuteMethod<\/code> (an <code>Action&lt;object&gt;<\/code>) and <code>CanExecuteMethod<\/code> (a <code>Predicate&lt;object&gt;<\/code>). These parameters are used to initialize the <code>_Execute<\/code> and <code>_CanExecute<\/code> properties, respectively.<\/li>\n<\/ul>\n\n\n\n<p>6. <strong><code>CanExecute<\/code> Method:<\/strong><\/p>\n\n\n\n<ul>\n<li>The <code>CanExecute<\/code> method is required by the <code>ICommand<\/code> interface. It checks whether the command can execute in its current state. It delegates this responsibility to the <code>_CanExecute<\/code> method provided during construction.<\/li>\n<\/ul>\n\n\n\n<p>7. <strong><code>Execute<\/code> Method:<\/strong><\/p>\n\n\n\n<ul>\n<li>The <code>Execute<\/code> method is required by the <code>ICommand<\/code> interface. It is called when the command is invoked. It delegates the execution to the <code>_Execute<\/code> method provided during construction.<\/li>\n<\/ul>\n\n\n\n<p>This class is designed to encapsulate the logic associated with a command, making it easy to create instances of <code>ICommand<\/code> in a concise way. <\/p>\n\n\n\n<p>This is especially useful when defining commands for user interface elements like buttons in XAML-based frameworks. <\/p>\n\n\n\n<p>It allows developers to specify the execution and can-execute logic in a clean and straightforward manner.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This code defines a class named PopupCommand that implements the ICommand interface. The ICommand interface is commonly used in WPF and other XAML-based frameworks to represent a command that can be bound to user interface elements such as buttons. Explanation as follows: 1. ICommand Interface: 2. PopupCommand Class: 3. CanExecuteChanged Event: 4. Private Properties: 5. [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":477,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[51,32,52,135],"tags":[53,23,54],"_links":{"self":[{"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/posts\/704"}],"collection":[{"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/comments?post=704"}],"version-history":[{"count":1,"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/posts\/704\/revisions"}],"predecessor-version":[{"id":705,"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/posts\/704\/revisions\/705"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/media\/477"}],"wp:attachment":[{"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/media?parent=704"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/categories?post=704"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kop.lat\/blog\/wp-json\/wp\/v2\/tags?post=704"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}