Visual Basic基础

1.基本语句使用方法

Select Case语句

'定义参数格式
Dim a, b As String
Dim c As DataTable
Dim d As String=""
Dim student As New Student()

Select Case a
    Case "1"
              b= "aaa "
              Exit Select
    Case "2", "3"
              b= "bbb'" & strSyllabusGUID & "' "
              Exit Select
End Select

 try-catch

Public Shared Function Delete(ByVal ids As String, ByVal user As String) As String
Try
　　'代码
Catch ex As Exception
　　'异常
End Try
End Function

 If语句

If 1=1 Then
       ' 如果执行成功
        Return "true"
Else
        ' 如果执行失败
       Return "false"
End If

 For循环的使用

For i = 0 To 10
    '执行循环体代码
Next

 for each 的使用

For Each row As DataRow In dtDataTable.Rows
 　strDetail = row.Item("Detail")
　 strDetail = row("Detail") '简写方式
    If t.ID = Guid.Empty Then
        Continue For '结束本次循环
    End If
　 Exit For '跳出循环
Next

将DataTable数据插入到数组逗号隔开

Dim vouchGUIDArray() As String
ReDim vouchGUIDArray(dtNew.Rows.Count - 1)    '声明数组的大小
For i = 0 To dtNew.Rows.Count - 1
     vouchGUIDArray(i) = dtNew.Rows(i).Item("VouchGUID").ToString()
Next
Return String.Join(",", vouchGUIDArray).ToString() '返回

...