Sun of Beach

"Defines a scope, outside of which an object or objects will be disposed."
--MSDN

using Statement is a very useful, it can dispose object after using at once.

i always put it to open/close the Database connection. In last few days, i assigned a task, convert the ui control to a customer class. I must loop all the controls and calculate their position and size. What a crazy! Because of I'm afraid the performance going bad during i looping the controls. So, i use the using statement.

using(UserControl userControl = Screen.Controls[i] as UserControl)
{
...
}

Oh, shxt! The nightmare comes. The controls which on screen disappear one by one! I guess maybe something wrong after generating the controls at first. but I wrong. The using statement makes the userControl which referenced from UI control to null, so the UI Control is null too.

Ah, i'm so stupid.

if you have read this artical "Walkthrough: Printing a Local Report without Preview" in Microsoft MSDN". Then you will know the PrintPage Event will be trigged by the content printed to file, printer or screen.

After you click the print button, the screen will be printed direcrtly without any notice.

So, if you want do something before the printing like me. You'd better to subscript the BeginPrint Event in code. Let's see how to do this.

First, make a judgment of what action trigs this event by e.PrinAction.



if (e.PrintAction == PrintAction.PrintToPrinter){...}

i need to show a modal dialog for confirm to print the screen or not, then,
write this in my code.

printDlg = new PrintDialog();if (printDlg.ShowDialog()!= DialogResult.OK){e.Cancel = true;}


Finish! Enjoy