{"id":660,"date":"2011-09-15T19:33:33","date_gmt":"2011-09-15T19:33:33","guid":{"rendered":"http:\/\/dirk.schuermans.me\/?p=660"},"modified":"2016-01-07T10:46:33","modified_gmt":"2016-01-07T10:46:33","slug":"asp-net-inline-tags","status":"publish","type":"post","link":"https:\/\/dirk.schuermans.me\/?p=660","title":{"rendered":"ASP.NET inline tags"},"content":{"rendered":"

Hey everyone!<\/p>\n

Recently I’ve started on my “Professional ASP.NET 4 in C# (and VB)” book to get my knowledge of ASP.NET up.<\/p>\n

One of the things I’ve noticed was that nowhere in the first chapter(s) they explained the difference between all the ASP.NET inline tags (such as <% … %>, <%$ … %>, etc)<\/p>\n

Therefor I’ve decided to put together this small overview of all the different inline tags and what they do. (Yes, it’s for my convenience too).<\/p>\n

This post will cover the following inline tags:<\/p>\n

    \n
  1. <% … %><\/li>\n
  2. <%= … %><\/li>\n
  3. <%# … %><\/li>\n
  4. <%& … %><\/li>\n<\/ol>\n

    I think it’s obvious what the <%@ … %> tags do \ud83d\ude09
    \nThe <%– … –> tags serve as server-side comments. Meaning those comments will not be visible in the HTML source code.<\/p>\n

    <\/p>\n

    The “<% … %>” tags<\/h3>\n

    This one is probably the most used inline ASP tag there is.
    \nThis tag serves the purpose of an embedded code block<\/strong>. It allows a developer to use code (C#\/VB) in between normal HTML code.<\/p>\n

    An example:<\/p>\n

    \r\nHello world!<br \/>\r\nIt is\r\n<% if(DateTime.Now.Hour < 6 && DateTime.Now.Hour >= 0){ %>\r\nnight now!\r\n<% } else { %>\r\nday now!\r\n<% } %>\r\n<\/pre>\n
    The “<%= … %>” tags<\/h3>\n
    These tags allow the developer to display something, for example a variable declared in the code behind file, on the page.<\/p>\n
    They can also be used to display properties of .NET object, such as DateTime:<\/p>\n
    \r\nHello world!<br \/>\r\nThe time now is <%= DateTime.Now.ToString() %><br \/>\r\n<\/pre>\n
    The “<%# … %>” tags<\/h3>\n
    These tags are used for data binding<\/strong> in databound controls, such as the ListBox, DropDownList, …
    \nThe “Page.DataBind()”<\/strong> must be called first, all <%# … %> tags will be evaluated then.<\/p>\n
    An example that will display the text the user has inputted in another label:<\/p>\n
    \r\n<form id=\"form1\" runat=\"server\">\r\n\tEnter some text:\r\n\t<asp:TextBox ID=\"TextBox1\" runat=\"server\"><\/asp:TextBox><br \/>\r\n\t<br \/>\r\n\t<asp:Button ID=\"Button1\" runat=\"server\" OnClick=\"Button1_Click\" \/><br \/>\r\n\t<br \/>\r\n\t<asp:Label ID=\"Label1\" runat=\"server\" Text=\"<%# TextBox1.Text %>\"><\/asp:Label>\r\n<\/form>\r\n<\/pre>\n
    And then in the code behind:<\/p>\n
    \r\nprotected void Button1_Click(object sender, EventArgs e)\r\n{\r\n\tPage.DataBind();\r\n}\r\n<\/pre>\n
    The “<%$ … %>” tags<\/h3>\n
    These tags define an expression of one of the following types:<\/p>\n