本文整理汇总了VB.NET中System.Data.SqlTypes.INullable.IsNull属性的典型用法代码示例。如果您正苦于以下问题：VB.NET INullable.IsNull属性的具体用法？VB.NET INullable.IsNull怎么用？VB.NET INullable.IsNull使用的例子？那么恭喜您, 这里精选的属性代码示例或许可以为您提供帮助。
在下文中一共展示了INullable.IsNull属性的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: WorkWithSqlNulls
Private Sub WorkWithSqlNulls()
Dim table As New DataTable()
' Specify the SqlType for each column.
Dim idColumn As DataColumn = _
table.Columns.Add("ID", GetType(SqlInt32))
Dim descColumn As DataColumn = _
table.Columns.Add("Description", GetType(SqlString))
' Add some data.
Dim row As DataRow = table.NewRow()
row("ID") = 123
row("Description") = "Side Mirror"
table.Rows.Add(row)
' Add null values.
row = table.NewRow()
row("ID") = SqlInt32.Null
row("Description") = SqlString.Null
table.Rows.Add(row)
' Initialize variables to use when
' extracting the data.
Dim isColumnNull As SqlBoolean = False
Dim idValue As SqlInt32 = SqlInt32.Zero
Dim descriptionValue As SqlString = SqlString.Null
' Iterate through the DataTable and display the values.
For Each row In table.Rows
' Assign values to variables. Note that you
' do not have to test for null values.
idValue = CType(row("ID"), SqlInt32)
descriptionValue = CType(row("Description"), SqlString)
' Test for null value with ID column
isColumnNull = idValue.IsNull
' Display variable values in console window.
Console.Write("isColumnNull={0}, ID={1}, Description={2}", _
isColumnNull, idValue, descriptionValue)
Console.WriteLine()
Next row
End Sub