C# – ASP.NET Dynamically Change User Control Source

asp.netcnetuser-controlsvisual studio

The Scenario

I have an ASP.Net Web Project that uses a master page.
This master page contains a menu in the form of a user control.
Sometimes I want to dynamically change this to use a different type of menu user control.

The current code to register the user control

<%@ Register TagPrefix="chase" TagName="topMenu"  Src="~/UserControls/TopMenu.ascx" %>

Inside the body tags

 <div id="menuRow">
     <chase:topMenu runat="server" />
 </div>

The Question

Is there anyway I can change the "SRC" attribute in the register code dynamically to use a different user control?!

Help greatly appreciated

EDIT:

Tried This Code But I Receive An 'Invalid Cast Exception'

TopMenu uh3 = (TopMenu)this.LoadControl("~/UserControls/TopMenu.ascx");
            menuRow.Controls.Add(uh3);

'Unable to cast object of type 'ASP.usercontrols_topmenu_ascx' to type 'SwintonTaxiWeb.UserControls.TopMenu'.'

Best Answer

What if you add your user control at runtime whichever you need.

UserControls_header3 uh3 = (UserControls_header3)this.LoadControl(header3);
phHeaderControls.Controls.Add(uh3);

Related Solutions

Visual-studio – Should I add the Visual Studio .suo and .user files to source control

These files contain user preference configurations that are in general specific to your machine, so it's better not to put it in SCM. Also, VS will change it almost every time you execute it, so it will always be marked by the SCM as 'changed'. I don't include either, I'm in a project using VS for 2 years and had no problems doing that. The only minor annoyance is that the debug parameters (execution path, deployment target, etc.) are stored in one of those files (don't know which), so if you have a standard for them you won't be able to 'publish' it via SCM for other developers to have the entire development environment 'ready to use'.

C# – Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on

As per Prerak K's update comment (since deleted):

I guess I have not presented the question properly.

Situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread.

So only accessing the value so that corresponding data can be fetched from the database.

The solution you want then should look like:

UserContrl1_LOadDataMethod()
{
    string name = "";
    if(textbox1.InvokeRequired)
    {
        textbox1.Invoke(new MethodInvoker(delegate { name = textbox1.text; }));
    }
    if(name == "MyName")
    {
        // do whatever
    }
}

Do your serious processing in the separate thread before you attempt to switch back to the control's thread. For example:

UserContrl1_LOadDataMethod()
{
    if(textbox1.text=="MyName") //<<======Now it wont give exception**
    {
        //Load data correspondin to "MyName"
        //Populate a globale variable List<string> which will be
        //bound to grid at some later stage
        if(InvokeRequired)
        {
            // after we've done all the processing, 
            this.Invoke(new MethodInvoker(delegate {
                // load the control with the appropriate data
            }));
            return;
        }
    }
}