功能强大的Tostring()

//2007年4月24日
this.TextBox6.Text = System.DateTime.Now.ToString("D");
//2007-4-24
this.TextBox7.Text = System.DateTime.Now.ToString("d");

//2007年4月24日 16:30:15
this.TextBox8.Text = System.DateTime.Now.ToString("F");
//2007年4月24日 16:30
this.TextBox9.Text = System.DateTime.Now.ToString("f");

//2007-4-24 16:30:15
this.TextBox10.Text = System.DateTime.Now.ToString("G");
//2007-4-24 16:30
this.TextBox11.Text = System.DateTime.Now.ToString("g");

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Tags: vb.net

Option Explicit
Private WithEvents NewTextBox As TextBox
'通过使用WithEvents关键字声明一个对象变量为新的命令按钮

Private Sub Command1_Click()
If NewTextBox Is Nothing Then
Set NewTextBox = Controls.Add("VB.TextBox", "cmdNew", Form1)
NewTextBox.Move 200, 200
NewTextBox.Width = Form1.Width - 450
NewTextBox.Height = Form1.Height - 1400
NewTextBox.Visible = True
End If
End Sub

Private Sub Command2_Click()
If NewTextBox Is Nothing Then
Exit Sub
Else
Controls.Remove NewTextBox
Set NewTextBox = Nothing
End If
End Sub

Tags: vb.net

Thread线程启动方法,一般来说要么是一个无参数的方法,要么是一个带有object参数的方法并且在Start时传递参数的值。
但是我们可以利用一些技巧给方法传递不受限制的参数。这些方法又可以在实际使用过程相互融合。
方法简单直接上代码,供君参考。

Imports System.Threading Module Module1 Sub Main() '第一种：在Start中传递参数值，但方法中的参数类型需为object类型 Dim t1 As New Thread(AddressOf CountNumber) t1.Start(10) '第二种：通过Lambda表达式创建线程,可以传递任意的参数 Dim t2 As New Thread(Sub() PrintNumber(20) End Sub) t2.Start() '第三种：通过实例化类来传递参数,然后调用类方法 Dim c As New Count(10) Dim t3 As New Thread(AddressOf c.CountNumber) t3.Start() '第四种：通过传递类或结构,以达到向方法传递多个参数 Dim p As New Person() With { .FirstName = "严"， .LastName = "查散" } Dim t4 As New Thread(AddressOf ShowName) t4.Start(p) Console.Read() End Sub '传递单个参数 Private Sub CountNumber(number As Object) Dim sum As Integer For i As Integer = 1 To Integer.Parse(number) sum += i Next Console.WriteLine(sum) End Sub '传递非object参数 Private Sub PrintNumber(number As Integer) Console.WriteLine(number) End Sub '把方法包装成类，在实例化时传递参数 Class Count Dim number As Integer Sub New(number As Integer) Me.number = number End Sub Public Sub CountNumber() Dim sum As Integer For i As Integer = 1 To Integer.Parse(number) sum += i Next Console.WriteLine(sum) End Sub End Class '传递一个类或结构达到传递多个参数 Private Sub ShowName(person As Object) Dim myPerson As Person = CType(person, Person) Console.WriteLine(myPerson.FirstName & myPerson.LastName) End Sub Class Person Public Property FirstName As String Public Property LastName As String End Class End Module

Tags: vb.net