VB.Net“IsDBNull”的C#等价物是什么
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What is the C# equivalent of VB.Net " IsDBNull"
提问by Chandrasekhar Sahoo
In VB.Net you can write :
在 VB.Net 你可以这样写：
If Not IsDBNull(oCustomerNameDataRow(0)) Then
cbCustomerName.Items.Add(oCustomerNameDataRow(0).ToString
End If
What is the equivalent of method IsDBNull in C#?
C# 中 IsDBNull 方法的等价物是什么？
回答by Дмитрий Чистик
if (!DBNull.Value.Equals(oCustomerNameDataRow[0]))
{
//something
}
回答by Bj?rn-Roger Kringsj?
I would say the the equivalent of the IsDBNullmethod (Microsoft.VisualBasic.Information)located in the Microsoft.VisualBasicassembley
我会说等效于位于Microsoft.VisualBasicassembley中的IsDBNull方法（Microsoft.VisualBasic.Information）
Public Function IsDBNull(ByVal Expression As Object) As Boolean
If Expression Is Nothing Then
Return False
ElseIf TypeOf Expression Is System.DBNull Then
Return True
Else
Return False
End If
End Function
Dim result As Boolean = IsDBNull(Nothing)
is the IsDBNullmethod (System.Convert)located in the mscorlibassembley:
是位于mscorlib汇编中的IsDBNull方法(System.Convert)：
public static bool IsDBNull(object value) {
if (value == System.DBNull.Value) return true;
IConvertible convertible = value as IConvertible;
return convertible != null? convertible.GetTypeCode() == TypeCode.DBNull: false;
}
bool result = System.Convert.IsDBNull(null);
回答by AminRostami
try this:
尝试这个：
create the Extension Method. follow this:
创建Extension Method. 按照这个：
public static bool IsDBNull(this object val)
{
return Convert.IsDBNull(val);
}
and the use from this Extension Method.
以及由此而来的使用Extension Method。
if(oCustomerNameDataRow[0].IsDBNull())
{
// ...
}
I hope useful.
我希望有用。
