в 16:40, 26 мая 2010

2010-05-26T16:40:30Z

Admin: 1 версия

2010-05-26T12:54:04Z

1 версия

Новая страница

==AddHandler and AddressOf==

<source lang="vbnet">Option Strict On
imports System
imports System.Drawing
imports System.Windows.Forms
public class MouseEnterHoverLeave : inherits Form
private btn as Button
public sub New()
Size = new Size(400,400)
btn = new Button()
btn.Parent = me
btn.Location = new Point(50,50)
btn.Size = new Size(150,25)
AddHandler btn.MouseEnter, AddressOf btn_MouseEnter
AddHandler btn.MouseHover, AddressOf btn_MouseHover
AddHandler btn.MouseLeave, AddressOf btn_MouseLeave
end sub
public shared sub Main()
Application.Run(new MouseEnterHoverLeave())
end sub
private sub btn_MouseEnter(ByVal sender as object,ByVal e as EventArgs)
btn.Text = "MouseEnter"
Console.WriteLine("Button MouseEnter")
end sub
private sub btn_MouseHover(ByVal sender as object,ByVal e as EventArgs)
btn.Text = "MouseHover"
Console.WriteLine("Button MouseHover")
end sub
private sub btn_MouseLeave(ByVal sender as object,ByVal e as EventArgs)
btn.Text = "MouseLeave"
Console.WriteLine("Button MouseLeave")
end sub
protected overrides sub OnMouseEnter(ByVal e as EventArgs)
myBase.OnMouseEnter(e)
Console.WriteLine("Form MouseEnter")
end sub
protected overrides sub OnMouseHover(ByVal e as EventArgs)
myBase.OnMouseHover(e)
Console.WriteLine("Form MouseHover")
end sub
protected overrides sub OnMouseLeave(ByVal e as EventArgs)
myBase.OnMouseLeave(e)
Console.WriteLine("Form MouseLeave")
end sub
end class</source>

==AddressOf operator==

<source lang="vbnet">Module Module1
Delegate Sub GreetingMethod()
Dim Greeting As New GreetingMethod(AddressOf MorningEnglish)
Sub MorningEnglish()
Console.WriteLine("Good morning")
End Sub
Sub AfternoonEnglish()
Console.WriteLine("Good afternoon")
End Sub
Sub EveningEnglish()
Console.WriteLine("Good evening")
End Sub
Sub MorningSpanish()
Console.WriteLine("Buenas dias")
End Sub
Sub AfternoonSpanish()
Console.WriteLine("Buenos tardes")
End Sub
Sub EveningSpanish()
Console.WriteLine("Buenos noches")
End Sub
Sub Main()
Greeting = AddressOf MorningEnglish
Greeting = AddressOf AfternoonEnglish
Greeting = AddressOf EveningEnglish
Greeting = AddressOf MorningSpanish
Greeting = AddressOf AfternoonSpanish
Greeting = AddressOf EveningSpanish
Greeting.Invoke()
End Sub
End Module</source>
<pre class=codeResult>Buenos noches</pre>

==Use EventHandler with AddressOf==

<source lang="vbnet">Module Module1
Sub AHandler(ByVal o As Object, ByVal e As System.EventArgs)
Console.WriteLine("handler")
End Sub

Sub Main()
Dim TodayDate As DateTime = Today()
Console.WriteLine(TodayDate)
Dim MyArray() As Double = {3.159, System.Math.Sqrt(2)}
Console.WriteLine(MyArray(1))
Dim MyHandler As EventHandler " = AddressOf AHandler
MyHandler(Nothing, Nothing)
Try
Dim MyException As Exception = New Exception("Raise an exception!")
Throw MyException
Catch e As Exception
Console.WriteLine(e.StackTrace())
End Try
End Sub
End Module</source>
<pre class=codeResult>11/05/2007 12:00:00 AM
1.4142135623731
Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an ob
ject.
at Module1.Main()</pre>

← Предыдущая	Версия 16:40, 26 мая 2010
(нет различий)

VB.Net Tutorial/Event/AddressOf - История изменений

в 16:40, 26 мая 2010

Admin: 1 версия