Web Forms error message: “This is not scriptlet. Will be output as plain text”

Question

In my ASP .NET Web Forms I have the following declarative code:

\' />         


        

Answer 1

You cannot use <%= ... %> to set properties of server-side controls. Inline expressions <% %> can only be used at aspx page or user control's top document level, but can not be embeded in server control's tag attribute (such as ..>).

If your TextBox is inside a DataBound controls such as GridView, ListView .. you can use: <%# %> syntax. OR you can call explicitly DataBind() on the control from code-behind or inline server script.

// code Behind file

protected void Page_Load(object sender, EventArgs e)
{     
        txtbox.DataBind();
}

ASP.NET includes few built-in expression builders that allows you to extract custom application settings and connection string information from the web.config file. Example:

• Resources
• ConnectionStrings
• AppSettings

So, if you want to retrieve an application setting named className from the portion of the web.config file, you can use the following expression:

However, above snippet isn't a standard for reading classnames from Appsettings.

You can build and use either your own Custom ExpressionBuilders or Use code behind as:

txtbox.CssClass = TEXTBOX_CSS_CLASS;

Check this link on building Custom Expression builders. Once you build your custom Expression you can display value like: