No. This is not possible; the ASCX virtual path must be supplied to dynamically load a User Control with markup and there is no internal mapping of types of virtual paths.
However, because I am still lazy, here is the approach I used that is still "type safe", and isolates the resolving issue to a single location in code. It still requires access to the "Page object", but otherwise takes care of the silly details.
Here is the brief explanation:
- Use the type to look-up the relative (to my root) ASCX path using a heuristic to map types from namespace to virtual path; allow a way to specify a manual mapping, and use that if specified
- Turn the relative path of the type into the correct/full virtual path
- Load the control with the virtual path
- Continue as though nothing has happened
Enjoy (I just copy'n'pasted select parts from my project, YMMV):
/// <summary>
/// Load the control with the given type.
/// </summary>
public object LoadControl(Type t, Page page)
{
try
{
// The definition for the resolver is in the next code bit
var partialPath = resolver.ResolvePartialPath(t);
var fullPath = ResolvePartialControlPath(partialPath);
// Now we have the Control loaded from the Virtual Path. Easy.
return page.LoadControl(fullPath);
} catch (Exception ex)
{
throw new Exception("Control mapping failed", ex);
}
}
/// <summary>
/// Loads a control by a particular type.
/// (Strong-typed wrapper for the previous method).
/// </summary>
public T LoadControl<T>(Page page) where T : Control
{
try
{
return (T)LoadControl(typeof (T), page);
} catch (Exception ex)
{
throw new Exception(string.Format(
"Failed to load control for type: {0}",
typeof (T).Name), ex);
}
}
/// <summary>
/// Given a partial control path, return the full (relative to root) control path.
/// </summary>
string ResolvePartialControlPath(string partialPath)
{
return string.Format("{0}{1}.ascx",
ControlPathRoot, partialPath);
}
The code listing for ControlResolver:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace FooBar
{
class ControlResolver
{
const string BaseNamespace = "TheBaseControlNameSpace";
readonly IDictionary<Type, string> resolvedPaths = new Dictionary<Type, string>();
/// <summary>
/// Maps types to partial paths for controls.
///
/// This is required for Types which are NOT automatically resolveable
/// by the simple reflection mapping.
/// </summary>
static readonly IDictionary<Type, string> MappedPartialPaths = new Dictionary<Type, string>
{
{ typeof(MyOddType), "Relative/ControlPath" }, // No virtual ~BASE, no .ASXC
};
/// <summary>
/// Given a type, return the partial path to the ASCX.
///
/// This path is the path UNDER the Control Template root
/// WITHOUT the ASCX extension.
///
/// This is required because there is no mapping maintained between the class
/// and the code-behind path.
///
/// Does not return null.
/// </summary>
public string ResolvePartialPath (Type type)
{
if (type == null)
{
throw new ArgumentNullException("type");
}
string partialPath;
if (resolvedPaths.TryGetValue(type, out partialPath))
{
return partialPath;
} else
{
string mappedPath;
if (MappedPartialPaths.TryGetValue(type, out mappedPath))
{
resolvedPaths[type] = mappedPath;
return mappedPath;
} else
{
// Since I use well-mapped virtual directory names to namespaces,
// this gets around needing to manually specify all the types above.
if (!type.FullName.StartsWith(BaseNamespace))
{
throw new InvalidOperationException("Invalid control type");
} else
{
var reflectionPath = type.FullName
.Replace(BaseNamespace, "")
.Replace('.', '/');
resolvedPaths[type] = reflectionPath;
return reflectionPath;
}
}
}
}
}
}
