AxHost.InvalidActiveXStateException Class
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AxHost.InvalidActiveXStateException Class


The exception that is thrown when the ActiveX control is referenced while in an invalid state.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)


[PermissionSetAttribute(SecurityAction.InheritanceDemand, Name = "FullTrust")]
[PermissionSetAttribute(SecurityAction.LinkDemand, Name = "FullTrust")]
public class InvalidActiveXStateException : Exception


Initializes a new instance of the AxHost.InvalidActiveXStateException class without specifying information about the member that referenced the ActiveX control.

System_CAPS_pubmethodAxHost.InvalidActiveXStateException(String, AxHost.ActiveXInvokeKind)

Initializes a new instance of the AxHost.InvalidActiveXStateException class and indicates the name of the member that referenced the ActiveX control and the kind of reference it made.


Gets a collection of key/value pairs that provide additional user-defined information about the exception.(Inherited from Exception.)


Gets or sets a link to the help file associated with this exception.(Inherited from Exception.)


Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.(Inherited from Exception.)


Gets the Exception instance that caused the current exception.(Inherited from Exception.)


Gets a message that describes the current exception.(Inherited from Exception.)


Gets or sets the name of the application or the object that causes the error.(Inherited from Exception.)


Gets a string representation of the immediate frames on the call stack.(Inherited from Exception.)


Gets the method that throws the current exception.(Inherited from Exception.)


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.(Inherited from Exception.)


Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetObjectData(SerializationInfo, StreamingContext)

When overridden in a derived class, sets the SerializationInfo with information about the exception.(Inherited from Exception.)


Gets the runtime type of the current instance.(Inherited from Exception.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Creates and returns a string representation of the current exception.(Overrides Exception.ToString().)


Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.(Inherited from Exception.)

The public properties and methods of an ActiveX control can only be referenced after the ActiveX control has been instantiated and initialized completely; otherwise the AxHost.InvalidActiveXStateException exception is thrown. The AxHost.InvalidActiveXStateException exception class contains the name of the member that made the reference and the member type. The member type is one of the AxHost.ActiveXInvokeKind enumerated values.

The following code example overrides the constructor, and the SetAboutBoxDelegate and AttachInterfaces methods of an AxHost derived class that wraps the Microsoft Masked Edit ActiveX Control. This code requires that you have created the generated source code by running the AxImp.exe on the MSMask32.ocx file with the /source switch to generate the wrapper class to be edited. This code is only shown in C# syntax because that is the only language output by the AxImp.exe.

public AxMaskEdBox()
  base("c932ba85-4374-101b-a56c-00aa003668dc") // The ActiveX control's class identifier.
    // Make the AboutBox method the about box delegate.
    this.SetAboutBoxDelegate(new AboutBoxDelegate(AboutBox));

public virtual void AboutBox()
    // If the instance of the ActiveX control is null when the AboutBox method 
    // is called, raise an InvalidActiveXStateException exception.
    if ((this.ocx == null))
        throw new System.Windows.Forms.AxHost.InvalidActiveXStateException(
          "AboutBox", System.Windows.Forms.AxHost.ActiveXInvokeKind.MethodInvoke);
    // Show the about box if the ActiveX control has one.
    if (this.HasAboutBox)

protected override void AttachInterfaces()
        // Attach the IMSMask interface to the ActiveX control.
        this.ocx = ((MSMask.IMSMask)(this.GetOcx()));
    catch (System.Exception ex)

.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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