IsError Method

Information.IsError Method

Returns a Boolean value indicating whether an expression is an exception type.

Namespace:  Microsoft.VisualBasic
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

public static bool IsError(
	Object Expression


Type: System.Object

Required. Object expression.

Return Value

Type: System.Boolean
Returns a Boolean value indicating whether an expression is an exception type.

For more detailed information, see the Visual Basic topic IsError Function.

IsError returns True if the expression represents an Object variable that derives from the Exception class in the System namespace.

An exception that derives from System.Exception can be caught with the Try...Catch...Finally statements.

The following example uses the IsError function to check if an expression represents a system exception.

Sub demonstrateIsError(ByVal firstArg As Integer)
    Dim returnVal As New Object
    Dim badArg As String = "Bad argument value" 
    Dim errorCheck As Boolean 
    If firstArg > 10000 Then
        returnVal = New System.ArgumentOutOfRangeException(badArg)
    End If
    errorCheck = IsError(returnVal)
End Sub

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

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