C# – .NET compact framework signature drawing GUI element

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;
        }
    }
}

You can't. It's occasionally a pain, but you wouldn't be able to call it using normal techniques anyway.

In a blog post I've suggested static interfaces which would only be usable in generic type constraints - but could be really handy, IMO.

One point about if you could define a constructor within an interface, you'd have trouble deriving classes:

public class Foo : IParameterlessConstructor
{
    public Foo() // As per the interface
    {
    }
}

public class Bar : Foo
{
    // Yikes! We now don't have a parameterless constructor...
    public Bar(int x)
    {
    }
}