What is MASTER? MASTER, short name for ASP.NET Master, is used as the file extension for ASP.NET Master pages. .MASTER files are text files that are used to store ASP.NET master/template page source code. See the sample .MASTER file included below.

File Extension: .MASTER

MIME Type: text/plain

File Content: ASP.NET Master Page

.MASTER files are ASP.NET Master pages, that are used to store ASP.NET master/template page source code. Here is a sample .MASTER ASP.NET Master page, section.master:

<%@ Master Language="C#" MasterPageFile="~/Quickstart.master" %>
<script runat="server">
    void Page_Init(object sender, EventArgs e) {
        DropDownList ddl;
        ddl = (DropDownList)Master.FindControl("LanguageSelect");
        ddl.Items.Clear();
        ddl.Items.Add(new ListItem("C#","C#"));
        ddl.Items.Add(new ListItem("VB","VB"));
    }
    void Page_Load(object sender, EventArgs e)
    {
        //This changes the Label text for the Quickstart Info
        //and also modifies the Page Title.
        const string BANNER_TITLE = "ASP.NET Quickstart Tutorials";

        Label lblBanner;
        lblBanner = (Label)Master.FindControl("BannerTitle");
        lblBanner.Text = BANNER_TITLE;

        Master.Page.Title = "ASP.NET QuickStart Tutorials";
    }
</script>
<asp:Content ID="Content1" ContentPlaceHolderID=Nav Runat=Server>
    <asp:TreeView ID="TreeView1" Runat="server" 
        DataSourceID="SiteMapDataSource1" ShowExpandCollapse="False"
        NodeIndent="10">
        <LevelStyles>
            <asp:TreeNodeStyle Font-Size="small" Font-Bold="True" /> 
            <asp:TreeNodeStyle ImageUrl="~/Images/Bullet_Nav_Big.gif" 
                Font-Bold="True" /> 
            <asp:TreeNodeStyle ImageUrl="~/Images/Bullet_Nav_Small.gif" /> 
        </LevelStyles>
        <SelectedNodeStyle Font-Underline="False" />
        <NodeStyle ChildNodesPadding="7" Font-Size="1em"/>
    </asp:TreeView>  
    <asp:SiteMapDataSource ID="SiteMapDataSource1" StartingNodeOffset="3" 
        Runat="server" />
    <br/>
    <table>
      <tr>
        <td>
          <asp:Image ImageUrl="~/Images/Arrow_Back.gif" runat="server"/>
        </td>
        <td>
          <asp:HyperLink Text="Back to ASP.NET Home" Font-Bold="true" 
          Font-Size="1em" Font-UnderLine="false" 
          NavigateUrl="~/aspnet/default.aspx" runat="server"/>
        </td>
      </tr>
    </table>
</asp:Content>
...

.MASTER ASP.NET Master page sample: Click sample.master to download.

Since .MASTER pages are in text format, you can use Notepad or any text editor to create or modify them. No special software is needed.

For for information on how to use .MASTER ASP.NET Master pages, see links below:

• ASP.NET Master Pages, by Microsoft.