C Form Close vs Form Dispose

Question

I am new to C   and I tried to look at the earlier posts but did not find a good answer   In a C  Windows Form Application with a single form  is using Form Close   better or Form Dispose     MSDN says that all resources within the object are closed and the form is disposed when a Close is invoked  Inspite of which  I have come across several examples online which follow a Dispose rather than a Close   Does one have an advantage over the other  Under which scenarios should we prefer one over the other

User · Answer

Close   - managed resource can be temporarily closed and can be opened once again   Dispose   - permanently removes managed or not managed resource

User · Answer

Using usingis a pretty good way   using  MyForm foo   new MyForm          if  foo ShowDialog      DialogResult OK                   your code

User · Answer

What I have just experiment with VS diagnostic tools is I called this Close   then formclosing event triggered  Then When I call this Dispose   at the end in Formclosing event where I dispose many other objects in it  it cleans everything much much smoother

User · Answer

If you use form close   in your form and set the FormClosing Event of your form and either use  form close   in this Event  you fall in unlimited loop and Argument out of range happened and the solution is that change the form close   with form dispose   in Event of FormClosing  I hope this little tip help you

User · Answer

This forum on MSDN tells you       Form Close   sends the proper Windows   messages to shut down the win32   window  During that process  if the   form was not shown modally  Dispose is   called on the form  Disposing the form   frees up the unmanaged resources that   the form is holding onto         If you do a form1 Show   or   Application Run new Form1     Dispose   will be called when Close   is called       However  if you do form1 ShowDialog     to show the form modally  the form   will not be disposed  and you ll need   to call form1 Dispose   yourself   I   believe this is the only time you   should worry about disposing the form   yourself

User · Answer

Not calling Close probably bypasses sending a bunch of Win32 messages which one would think are somewhat important though I couldn t specifically tell you why     Close has the benefit of raising events  that can be cancelled  such that an outsider  to the form  could watch for FormClosing and FormClosed in order to react accordingly   I m not clear whether FormClosing and or FormClosed are raised if you simply dispose the form but I ll leave that to you to experiment with

User · Answer

As a general rule  I d always advocate explicitly calling the Dispose method for any class that offers it  either by calling the method directly or wrapping in a  using  block     Most often  classes that implement IDisposible do so because they wrap some unmanaged resource that needs to be freed   While these classes should have finalizers that act as a safeguard  calling Dispose will help free that memory earlier and with lower overhead   In the case of the Form object  as the link fro Kyra noted  the Close method is documented to invoke Dispose on your behalf so you need not do so explicitly   However  to me  that has always felt like relying on an implementaion detail   I prefer to always call both Close and Dispose for classes that implement them  to guard against implementation changes errors and for the sake of being clear   A properly implemented Dispose method should be safe to invoke multiple times

[c#] C# Form.Close vs Form.Dispose

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