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Why is that the scriptPath variable is out of scope in the bottom of the code?
Shouldn't it be in scope throughout this page? In MVC, if I mark this on top of the page like
@{
string scriptPath = "assets/scripts/",
gkoConfig = "GkoConfig.js";
}
it is available throughout the current View. What am I missing now that I'm back to WebForms for a while?
If I change the code position, It get's weirder as inside the <head> I no longer have access to teh variable, but I do have, inside the <body> now... :-/
226
Variables are declared using the var keyword, or by using the type (if you want to declare the type), but ASP.NET can usually determine data types automatically.
In C#, when we declare a variable inside a class, the variable can be accessed within the class. This is known as class level variable scope. Class level variables are known as fields and they are declared outside of methods, constructors, and blocks of the class.
The scope of a variable is defined as its range in the program under which it can be accessed. In other words, "The scope of a variable is the portion of the program within which it is defined and can be accessed."
When you declare a variable in a Web Forms .aspx file, you’re actually declaring a local variable inside an auto-generated rendering method. ASP.NET generates separate rendering methods for all tags marked runat="server", so you actually get a separate method for your head element. Now, the variable you declare can only exist in one of these methods - hence the 'weird' behavior.
You can see how this works if you pre-compile your application using aspnet_compiler.exe. You will get compiled DLL files for each of your web forms pages; just open one of those up in Reflector to see the generated code. I wrote a minimal equivalent of your code with the variable declared outside the head tag, and here’s the top-level render method that I got:
private void __Render__control1(HtmlTextWriter __w, Control parameterContainer)
{
string str = "scripts/";
__w.Write("\r\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\r\n\r\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\r\n");
parameterContainer.Controls[0].RenderControl(__w);
__w.Write("\r\n<body>\r\n ");
parameterContainer.Controls[1].RenderControl(__w);
__w.Write("\r\n <script type=\"text/javascript\" src=\"");
__w.Write(str);
__w.Write("jquery-1.4.1.min.js\"></script>\r\n</body>\r\n</html>\r\n");
}
You see that the variable that I declared (here named str) is scoped to this method, and it's calling other methods to render the head (and a form element marked runat="server".)
A quick and dirty solution might be to simply remove the runat="server" from your head tag; however, I’d recommend that you declare a protected variable in your code-behind class for this. Adding a line like this to your code-behind file would work:
protected string scriptPath, gkoConfig;
You can then use these variables anywhere in your Web Forms code.
153
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