Thu, June 2, 2005, 12:52 PM under
MobileAndEmbedded
As a Pocket PC user and a NETCF 1.0 developer, you are familiar with the problem of showing different forms in the same application while preventing the user from navigating between forms from the "running list" (not to mention returning to the correct form after closing a sub-form). This was described previously
here (look at the fourth entry: 4. Moving between applications)
So in NETCF 1.0, if you simply use
ShowDialog to display another form:
a) The new form (specifically its caption/text) appears in the "running programs list"
b) The original form also appears in the list, which means you can navigate to it (although it appears disabled once activated)
c) There is potential for closing the second form and returning to another window on the PPC (the original form has moved back in the z-order)
With CF 2.0 you can use the new
Owner property of the Form and hence get rid of every problem from the above list.
Do not confuse the Owner property with the Parent property, which is inherited from Control and is not intended to be used with formsRun the following snippet (assume it is in the button click event handler of Form1 in VS2005 NETCF 2.0 project):
Dim f As New Form2()
f.Owner = Me
f.ShowDialog()
...you'll notice that only one entry for your application exists in the running list. The only potentially strange thing is that it has the caption of the first form (while the body of the form is clearly that of Form2)! This is easily rectified with the following modification (this time in C#):
Form2 f = new Form2();
f.Owner = this;
string s = this.Text; //make a copy of the original caption
this.Text = f.Text; //set our caption to the form we are about to show
f.ShowDialog();
this.Text = s; //restore the original caption once the second form is closed
Although I would have preferred the original snippet to exhibit the behaviour of the second snippet, still we must agree that this is a step forward from NETCF 1.0!