本文整理匯總了VB.NET中System.Data.SqlTypes.INullable.IsNull屬性的典型用法代碼示例。如果您正苦於以下問題：VB.NET INullable.IsNull屬性的具體用法？VB.NET INullable.IsNull怎麽用？VB.NET INullable.IsNull使用的例子？那麽, 這裏精選的屬性代碼示例或許可以為您提供幫助。
在下文中一共展示了INullable.IsNull屬性的1個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的VB.NET代碼示例。
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