Visual Basic

<br />
public class MyButton<br />
 private event MyButtonClick<br />
 private withevents btn as button<br />
 public sub new<br />
  btn = new button<br />
  btn.text="test"<br />
  me.controls.add(btn)<br />
 end sub<br />
<br />
 private sub btn_click (sender as object,e as eventargs) handles btn.click<br />
  raiseevent mybuttonclick<br />
 end sub<br />
end class<br />
<br />
public class MyForm<br />
 private withevents mybtn as MyButton<br />
 public sub new<br />
  mybtn = new mybutton<br />
 end sub<br />
 <br />
 private sub mybtn_mybuttonclick() handles mybtn.mybuttonclick<br />
  'Do your code here <br />
 end sub<br />
end class<br />

Tom Deketelaere wrote:

Its the form that handles your control's mybuttonclick event

Valkiri wrote:

How do I reference a method in the usercontrols parent container

Valkiri wrote:

Somewhat obviously at design time these classes do not know their eventual parent.

Valkiri wrote:

The buttons click event would call the forms SaveAll method.

Valkiri wrote:

I believe that I should be able to have a library of buttons that have been specialized that call the parent form parentform.SaveALL to save parentForm.DeleteALL to delete, parentform.ChangeFBackground("Blue") to change the forms background etc.

Valkiri wrote:

My problem is how to code a reference to the form when the form has not even been created yet

Valkiri wrote:

Look what I've Found:
http://www.codeproject.com/KB/cs/agusercontrol.aspx[^]

Valkiri wrote:

Are you stating that controls should never (hardly ever anyway) call the form.

Valkiri wrote:

Am I correct in understanding that you advise that the form should listen for and catch the, say, click event and act upon it.

Valkiri wrote:

If the form is waiting to catch the event does this mean that the controls say click event has no code in it.

Valkiri wrote:

Do you know of URLs / articles that address this question of using control libraries.

dim dt as new Datatable 
da.fill(dt)
(other code)
dt.Dispose()
dt = New DataTable
(other code)
da.fill(dt)

Coding123456 wrote:

my properties need to reference the same datatable (which contains data or I set to Nothing indicating no data) to make sense of the data and the program needs to reference the same class.

Coding123456 wrote:

If the datatable happens to be disposed (as it contained no data) as in your example I would get an error when I reference it.

Dave Kreskowiak wrote:

I think you have left out some things in your description. Setting the datatable reference to Nothing destroys the table, colums, data, everything. You cannot reuse that object. Now you're saying you WANT to reuse the datatable and its columns, but no data. Which is it??

Coding123456 wrote:

Using .NET apparently the garbage collector does not destroy the object as long as I don't go out of scope

Coding123456 wrote:

For example, if an object is set to Nothing inside a procedure and the next line of code creates an object of the same name, the first object may not yet be destroyed and a reference to the new object might incorrectly return the first object

Coding123456 wrote:

I'm not entirly comfortable with this approach as it seems bad to set it to nothing if I actually intend to reuse it again and again.

Colin Angus Mackay wrote:

Setting the reference to Nothing makes it unreachable (so long as there are no other references to it.)
If the object implements the IDisposable interface then you should, as a matter of good practice, call Dispose on the object.

If dt is nothing then 
  return "Default Name"
else
  return cstr(dt.rows(0).item("Name"))
end if

Colin Angus Mackay wrote:

I don't see a problem with that. If you set it to nothing and there is a consirerable amount of time before assigning new data then do so because in the intervening time the Garbage Collector can get it. If it is the very next statement where you assign data I don't really see much point.