13518219792
到底是加左边还是加右边啊？
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加左边的话可以用Format(number, "000000")，得到的数如果不足6位则自动在左边补0。
加右边的话，可以用
While Len(st)6
st=st+"0"
Wend
得到的st就保证6位
vb判断变量里的字符个数不够两个自动在前面补0，提供两种常用的方法;
1、根据长度判断;
a = 5 '注意这里a如果定义为数字类型（Integer、long等），补零后的变量尽量换一个其他变量值，比如b
If Len(a) 2 Then b = "0" a else b=a ‘如果a长度小于2，就前面补零
2、先补零，再取后2位
a=5
b = "0" a
b= Right(b, 2)
Public Sub AutoComplete(ByVal cmb As ComboBox, ByVal e As System.Windows.Forms.KeyPressEventArgs)
If cmb.DataSource Is Nothing Then
Return
End If
If e.KeyChar = Microsoft.VisualBasic.ChrW(Keys.Enter) Then
Return
End If
Dim strFindStr As String = ""
If e.KeyChar = Microsoft.VisualBasic.ChrW(Keys.Back) Then
If (cmb.SelectionStart = cmb.Text.Length) Then
If cmb.Text.Length 0 Then
strFindStr = cmb.Text.Substring(0, cmb.Text.Length - 1)
End If
Else
If cmb.SelectionStart 0 Then
strFindStr = cmb.Text.Substring(0, cmb.SelectionStart - 1)
End If
End If
e.Handled = False
Else
If (cmb.SelectionLength = 0) Then
strFindStr = cmb.Text + e.KeyChar
Else
If (cmb.SelectionStart = cmb.Text.Length) Then
strFindStr = e.KeyChar
Else
If cmb.SelectionStart 0 Then
strFindStr = cmb.Text.Substring(0, cmb.SelectionStart - 1) + e.KeyChar
Else
strFindStr = e.KeyChar
End If
End If
End If
End If
Dim intIdx As Integer = -1
Dim dv As DataView
If TypeOf (cmb.DataSource) Is DataTable Then
dv = CType(cmb.DataSource, DataTable).DefaultView
If strFindStr "" Then
dv.RowFilter = cmb.DisplayMember " Like '%" strFindStr "%'"
Else
dv.RowFilter = ""
End If
cmb.DataSource = dv
cmb.SelectedIndex = -1
cmb.Text = strFindStr
Else
dv = CType(cmb.DataSource, DataView)
If strFindStr "" Then
dv.RowFilter = cmb.DisplayMember " Like '%" strFindStr "%'"
Else
dv.RowFilter = ""
End If
cmb.DataSource = dv
cmb.SelectedIndex = -1
cmb.Text = strFindStr
End If
cmb.SelectionStart = strFindStr.Length
e.Handled = True
End Sub
Private Sub comboBox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles comboBox1.KeyPress
AutoComplete(sender, e)
End Sub
Dim a As String = "011"
Dim b As String = "1"
Dim c As String
c = (CInt(a) + CInt(b)).ToString.PadLeft(3, "0")
Label1.Text = c
-----------
将a,b转换为整型之后计算，再转换为string型，之后可以用PadLeft(3, "0")这个来左补零，3表示限定为三位，后面那个“0”就是限定不足3位补0。
'写入
Dim bytes() As Byte = {34, 23, 43, 43, 55, 3}
Dim items = (From item In bytes Select item.ToString("000")).ToArray()
System.IO.File.WriteAllLines("c:\test.txt", items)
'读取
Dim items2 = System.IO.File.ReadAllLines("c:\test.txt")
Dim bytes2 = (From item In items2 Select Byte.Parse(item)).ToArray()
For Each item In bytes2
Console.WriteLine(item.ToString())
Next
