Dynamic calling of members 1

[robertkjr3d]

How do I programmatically call a member of an unknown type?

I have form A... which opens up another form B. However Form A will be the parent of B.

In fact I have this code:

listing list1 = new listing();
list1.parent = this;
list1.Show();

In list1 parent is an object. Because it could come from any number of forms.

Now in the 'listing' code... I want to call a member of parent... unfortunately I can't do this normally by either:

parent.whatever = 0;

gives the compile error that object parent contains no definition of 'whatever'.

The other way that I know will work is to have a series of if/case statments that figure out where it did come from:

if (source == "Referral") 
{
    Referral r = (Referral)parent;
    r.whatever = 0; //and this will work
}

But isn't there a way I can programmatically find the objects and call them of the object parent without having to know before compile time what form is the parent?

Of course I would make sure that all the 'Parents' would have the 'whatever' I'm trying to reference. But I shouldn't have to know.. or use a series of case or if statements to do this.

-Robert

 

[JurkMonkey]

Ok, you are about to enter the world of Interfaces.

You could do .GetType() and switch the type but what a pain!

Instead, create an interface and pass that in.

public interface IMyInterface
{
int whatever{get; set;}
}

then your form can use IMyInterface:

public Form1 :System.Windows.Forms.Form, IMyInterface
{
private int mywhatever = 0;

public Form1()
{
InitializeComponent();
}

public int whatever
{
get
{
return mywhatever;
}
set
{
mywhatever = value;
}
}
}


Then in your Listing Form you would put this:

public Listing : System.Windows.Forms.Form
{
IMyInteface callingform;

public void SetCallingForm(IMyInterface frm)
{
callingform = frm;
}


private void Button1_Click(object sender, EventArgs e)
{
callingform.whatever = 1000;
}
}


Now you can pass in a form, a class, a customcontrol, anything that used IMyInterface.

 

[robertkjr3d]

Can I also call a function that way...

In earlier code... if I didn't get the compile error it would be:

parent.go();

How would I call a function undernearth an unknown form with this interface stuff?

 

[JurkMonkey]

simply add your interface declaration:

void Go();