DBNullColumn Class

Placeholder column used when the actual column type is not yet known.

Inheritance Hierarchy

SystemObject
  Altaxo.MainSuspendableDocumentNodeBase
    Altaxo.MainSuspendableDocumentLeafNode
      Altaxo.MainSuspendableDocumentLeafNodeWithSingleAccumulatedDataEventArgs
        Altaxo.MainSuspendableDocumentLeafNodeWithEventArgs
          Altaxo.DataDataColumn
            Altaxo.DataDBNullColumn

Namespace: Altaxo.Data
Assembly: AltaxoBase (in AltaxoBase.dll) Version: 4.8.3572.0 (4.8.3572.0)

Syntax

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public class DBNullColumn : DataColumn

The DBNullColumn type exposes the following members.

Constructors

	Name	Description
	DBNullColumn	Initializes a new instance of the DBNullColumn class.

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Properties

	Name	Description
	AccumulatedEventData	Gets the accumulated event data. (Inherited from SuspendableDocumentLeafNodeWithSingleAccumulatedDataT)
	AssignVector	Provides a setter property to which a vector can be assigned to. Copies all elements of the vector to this column. (Inherited from DataColumn)
	Count	Returns the row count, i.e. the one more than the index to the last valid data element in the column. (Overrides DataColumnCount)
	Data	Provides a setter property to which another data column can be assigned to. Copies all elements of the other DataColumn to this column. An exception is thrown if the data types of both columns are incompatible. See also CopyDataFrom(Object). (Inherited from DataColumn)
	Debug_AbsolutePath	Gets the absolute path of the node for debugging purposes. (Inherited from SuspendableDocumentNodeBase)
	FullName	Returns either the column name if the column has no parent table, or the parent table name, followed by a backslash and the column name if the column has a table. (Inherited from DataColumn)
	IsDirty	Column is dirty if either there are new changed or deleted rows, and no data changed event was fired for notification. This value is reseted after the data changed event has notified the change. (Inherited from DataColumn)
	IsDisposed	Gets a value indicating whether this instance is disposed. (Inherited from SuspendableDocumentNodeBase)
	IsDisposeInProgress	Gets a value indicating whether for this instance dispose is in progress, or the instance is already disposed. (Inherited from SuspendableDocumentNodeBase)
	IsReadOnly	Gets a value indicating whether the ICollectionT is read-only. (Inherited from DataColumn)
	IsSomeoneListeningToChanges	Gets a value indicating whether someone is listening to changes. For this, either the ParentObject or the Changed event must be set. (Inherited from SuspendableDocumentNodeBase)
	IsSuspended	Gets a value indicating whether this instance is suspended. (Inherited from SuspendableDocumentLeafNode)
	Item	Gets or sets the element at the specified index by a value of type AltaxoVariant. (Inherited from DataColumn)
	ItemType	Gets the type of the colum's items. (Overrides DataColumnItemType)
	Name	Gets the name of this document node. Null is returned if the name is not set or unknown. The set accessor will for most nodes throw a InvalidOperationException, since the name can only be set on IProjectItems. (Inherited from SuspendableDocumentNodeBase)
	ParentObject	Get / sets the parent object of this data column. (Inherited from DataColumn)
	TypeAndName	Returns the column type followed by a backslash and the column name. (Inherited from DataColumn)

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Methods

	Name	Description
	AccumulateChangeData(Object, EventArgs)	Accumulates the change data of the child. Currently only a flag is set to signal that the table has changed. (Inherited from DataColumn)
	AccumulateChangeData(Int32, Int32, Boolean)	Accumulates the change data provided in the arguments into the m_ChangeData member. (Inherited from DataColumn)
	AccumulatedChangeData_SetBackAfterResumeAndSuspend	Sets the change data without further processing. This function is infrastructure and intended to use only in OnResume after the parent has suspended this node again. (Inherited from SuspendableDocumentLeafNodeWithSingleAccumulatedDataT)
	AccumulatedEventData_Clear	Clears the accumulated event data. (Inherited from SuspendableDocumentLeafNodeWithSingleAccumulatedDataT)
	AccumulatedEventData_HasZeroOrOneEventArg	Determines whether there is no or only one single event arg accumulated. If this is the case, the return value is true. If there is one event arg accumulated, it is returned in the argument singleEventArg. The return value is false if there is more than one event arg accumulated. In this case the singleEventArg is null on return, and the calling function should use AccumulatedEventData to enumerate all accumulated event args. (Inherited from SuspendableDocumentLeafNodeWithSingleAccumulatedDataT)
	Add	Adds an item to the ICollectionT. (Inherited from DataColumn)
	Append	Appends data from another column to this column (Inherited from DataColumn)
	AppendToPosition	Appends data from another column to this column (Inherited from DataColumn)
	ChildDisposeMemberT	Helper function to dispose a child node of this instance. It helps to ensure the correct order: first, the child node is set to null and only then the child node is disposed. (Inherited from SuspendableDocumentNodeBase)
	Clear	Clears all rows. (Inherited from DataColumn)
	Clone	Creates a cloned instance of this object. (Overrides DataColumnClone)
	Contains	Determines whether the ICollectionT contains a specific value. (Inherited from DataColumn)
	CopyDataFrom	Copies the contents of another column o to this column. An exception should be thrown if the data types of both columns are incompatible. (Overrides DataColumnCopyDataFrom(Object))
	CopyHeaderInformationFrom	copies the header information, like label and so on from another column to this column ColumnName and ColumnNumber is not copied! (Inherited from DataColumn)
	CopyTo	Copies the elements of the ICollectionT to an Array, starting at a particular Array index. (Inherited from DataColumn)
	CreateColumnOfSelectedRows(IAscendingIntegerCollection)	Creates a new column, consisting only of the selected rows of the original column. (Inherited from DataColumn)
	CutToMaximumLength	Cuts the column to the provided length. The actual length of the column may be less than the provided parameter if the column contains empty elements. (Inherited from DataColumn)
	Dispose	Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources. (Inherited from SuspendableDocumentNodeBase)
	Dispose(Boolean)	Releases unmanaged and - optionally - managed resources. (Inherited from SuspendableDocumentNodeBase)
	EhParentTunnelingEventHappened	Is called by the parent when a tunneling event happened into the parent. (Inherited from SuspendableDocumentNodeBase)
	EhSelfChanged	Calls EhSelfChanged(EventArgs) with Empty. (Inherited from SuspendableDocumentLeafNodeWithEventArgs)
	EhSelfChanged(EventArgs)	Called if some member of this instance itself has changed. (Inherited from SuspendableDocumentLeafNode)
	EhSelfChanged(Int32, Int32, Boolean)	This function has to be called by derived classes if any changes in their data occur. (Inherited from DataColumn)
	EhSelfTunnelingEventHappened(TunnelingEventArgs)	Is called by this instance if a tunneling event happened into this instance. The tunneling event triggers the TunneledEvent and is additionally distributed to all childs of this instance. (Inherited from SuspendableDocumentNodeBase)
	EhSelfTunnelingEventHappened(TunnelingEventArgs, Boolean)	Is called by this instance if a tunneling event happened into this instance. The tunneling event triggers the TunneledEvent and is - depending on the provided parameter - also distributed to all childs of this instance. (Inherited from SuspendableDocumentNodeBase)
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object)
	Finalize	Finalizes an instance of the SuspendableDocumentNodeBase class. (Inherited from SuspendableDocumentNodeBase)
	GetColumnStyleType	Returns the type of the associated ColumnStyle for use in a worksheet view. (Overrides DataColumnGetColumnStyleType)
	GetEnumerator	Returns an enumerator that iterates through the collection. (Inherited from DataColumn)
	GetHashCode	Serves as the default hash function. (Inherited from Object)
	GetType	Gets the Type of the current instance. (Inherited from Object)
	GetVariantAt	This returns the value at a given index i as AltaxoVariant. (Overrides DataColumnGetVariantAt(Int32))
	HandleLowPriorityChildChangeCases	Handles the cases when a child changes, but a reaction is necessary only if the node is currently not suspended. (Inherited from SuspendableDocumentLeafNode)
	IndexOf	Determines the index of a specific item in the IListT. (Inherited from DataColumn)
	IndicesOf	Gets all indices where the element is equal to the value given in item. (Inherited from DataColumn)
	Insert	Inserts an item to the IListT at the specified index. (Inherited from DataColumn)
	InsertRows	Inserts nCount empty rows before row number nBeforeRow. (Overrides DataColumnInsertRows(Int32, Int32))
	IsElementEmpty	This function is used to determine if the element at index i is valid or not. If it is valid, the derived class function has to return false. If it is empty or not valid, the function has to return true. (Overrides DataColumnIsElementEmpty(Int32))
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object)
	OnAboutToBeResumed	Is called when the suspend level is still 1 (one), but is about to fall to zero, i.e. shortly before the call to OnResume. This function is not called before OnResumeSilently! (Inherited from SuspendableDocumentLeafNode)
	OnChanged	Fires the change event with the EventArgs provided in the argument. (Inherited from SuspendableDocumentNodeBase)
	OnResume	Is called when the suspend level falls down from 1 to zero by a call to Resume or a call to [M:Altaxo.Main.ISuspendToken.Dispose()]. (Inherited from SuspendableDocumentLeafNode)
	OnResumeSilently	Is called when the suspend level falls down from 1 to zero by a call to ResumeSilently. The implementation should delete any accumulated events, should also disarm the suspendTokens of the childs of this object, and should not fire any Changed events nor set the change state of the object to dirty. (Inherited from SuspendableDocumentLeafNode)
	OnSuspended	Called when the suspend level has just gone from 0 to 1, i.e. the object was suspended. (Inherited from SuspendableDocumentLeafNode)
	OnTunnelingEvent	Fires the TunneledEvent event. (Inherited from SuspendableDocumentNodeBase)
	Remove	Removes the first occurrence of a specific object from the ICollectionT. (Inherited from DataColumn)
	RemoveAt	Removes the IListT item at the specified index. (Inherited from DataColumn)
	RemoveRows	Removes a number of rows (given by nCount) beginning from nFirstRow, i.e. remove rows number nFirstRow ... nFirstRow+nCount-1. (Overrides DataColumnRemoveRows(Int32, Int32))
	Resume(ISuspendToken)	Resumes changed events by calling Resume for the provided suspend token, and setting the reference to the suspend token to null. If Event data were accumulated during the suspended state, a changed event is triggered for each event data. (Inherited from SuspendableDocumentNodeBase)
	Resume(ISuspendToken, EventFiring)	Resumes changed events, either with taking the accumulated event data into account (see Resume(ISuspendToken)) or discarding the accumulated event data (see ResumeSilently(ISuspendToken), depending on the provided argument eventFiring. (Inherited from SuspendableDocumentNodeBase)
	ResumeCompleteTemporarily	Resumes the object completely for only a short time. Thus, if object was suspended before, it will be suspended again when the function returns. (Inherited from SuspendableDocumentLeafNode)
	ResumeCompleteTemporarilyGetToken	Resumes the object completely for the time the returned token is referenced and not disposed. The return value is a token that had 'absorbed' the suspend count of the object, resulting in the suspend count of the object dropped to 0 (zero). When the returned token is finally disposed, the suspend count of the object is increased again by the 'absorbed' suspend count. (Inherited from SuspendableDocumentLeafNode)
	ResumeSilently	Resumes changed events by calling Resume for the provided suspend token, and setting the reference to the suspend token to null. All event data accumulated during the suspended state are discarded, and thus no change event is triggered even if the instance has changed during the suspended state. (Inherited from SuspendableDocumentNodeBase)
	SetDisposeInProgress	Sets the flag that dispose is in progress for this node and all child nodes recursively. (Inherited from SuspendableDocumentNodeBase)
	SetElementEmpty	This clears the cell at index i. (Overrides DataColumnSetElementEmpty(Int32))
	SetMemberAndRaiseSelfChangedT(NullableT, NullableT)	Sets a member variable of this instance and raise a change event with Empty if the new value is different from the old value. The comparison is done using the IEquatableT interface of the member variable. Note: to set members that implement IDocumentNode please use the Child... functions. (Inherited from SuspendableDocumentNodeBase)
	SetMemberAndRaiseSelfChangedT(T, T)	Sets a member variable of this instance and raise a change event with Empty if the new value is different from the old value. The comparison is done using the IEquatableT interface of the member variable. Note: to set members that implement IDocumentNode please use the Child... functions. (Inherited from SuspendableDocumentNodeBase)
	SetMemberEnumAndRaiseSelfChangedT	Sets a member variable (which is an Enum) of this instance and raise a change event with Empty if the new value is different from the old value. The comparison is done using the IEquatableT interface of the member variable. Note: to set members that implement IDocumentNode please use the Child... functions. (Inherited from SuspendableDocumentNodeBase)
	SetValueAt	Sets the value at a given index i with a value val, which is a AltaxoVariant. (Overrides DataColumnSetValueAt(Int32, AltaxoVariant))
	SuspendGetToken	Suspend will increase the SuspendLevel. (Inherited from SuspendableDocumentLeafNode)
	ToROVector	Creates a wrapper that implements IROVector with starting index = 0 and number of elements = Count. (Inherited from DataColumn)
	ToROVector(Int32, Int32)	Creates a wrapper that implements IROVector. (Inherited from DataColumn)
	ToString	Returns a string that represents the current object. (Inherited from Object)
	ToVector	Creates a wrapper that implements IVector with starting index = 0 and number of elements = Count. (Inherited from DataColumn)
	ToVector(Int32, Int32)	Creates a wrapper that implements IVector. (Inherited from DataColumn)
	TryGetName	Test if this item already has a name. (Inherited from SuspendableDocumentNodeBase)
	vop_Addition(AltaxoVariant, DataColumn)	Adds a scalar value to this data column. (Inherited from DataColumn)
	vop_Addition(DataColumn, DataColumn)	Adds another data column to this data column (item by item). (Inherited from DataColumn)
	vop_Addition_Rev(AltaxoVariant, DataColumn)	Adds this data column to a scalar value in reverse operand order. (Inherited from DataColumn)
	vop_Addition_Rev(DataColumn, DataColumn)	Adds this data column to another data column in reverse operand order. (Inherited from DataColumn)
	vop_And(AltaxoVariant, DataColumn)	Applies a logical AND between this data column and a scalar value. (Inherited from DataColumn)
	vop_And(DataColumn, DataColumn)	Applies a logical AND between this data column and another data column. (Inherited from DataColumn)
	vop_And_Rev(AltaxoVariant, DataColumn)	Applies a logical AND between a scalar value and this data column in reverse operand order. (Inherited from DataColumn)
	vop_And_Rev(DataColumn, DataColumn)	Applies a logical AND between another data column and this data column in reverse operand order. (Inherited from DataColumn)
	vop_Complement	Applies the bitwise complement operator. (Inherited from DataColumn)
	vop_Decrement	Applies the decrement operator. (Inherited from DataColumn)
	vop_Division(AltaxoVariant, DataColumn)	Divides this data column by a scalar value. (Inherited from DataColumn)
	vop_Division(DataColumn, DataColumn)	Divides this data column by another data column(item by item). (Inherited from DataColumn)
	vop_Division_Rev(AltaxoVariant, DataColumn)	Divides a scalar value by this data column. (Inherited from DataColumn)
	vop_Division_Rev(DataColumn, DataColumn)	Divides another data column by this data column. (Inherited from DataColumn)
	vop_False	Evaluates whether this column should be treated as logically false. (Inherited from DataColumn)
	vop_Greater(AltaxoVariant, DataColumn)	Tests whether this data column is greater than a scalar value. (Inherited from DataColumn)
	vop_Greater(DataColumn, DataColumn)	Tests whether this data column is greater than another data column. (Inherited from DataColumn)
	vop_Greater_Rev(AltaxoVariant, DataColumn)	Tests whether a scalar value is greater than this data column. (Inherited from DataColumn)
	vop_Greater_Rev(DataColumn, DataColumn)	Tests whether another data column is greater than this data column. (Inherited from DataColumn)
	vop_GreaterOrEqual(AltaxoVariant, DataColumn)	Tests whether this data column is greater than or equal to a scalar value. (Inherited from DataColumn)
	vop_GreaterOrEqual(DataColumn, DataColumn)	Tests whether this data column is greater than or equal to another data column. (Inherited from DataColumn)
	vop_GreaterOrEqual_Rev(AltaxoVariant, DataColumn)	Tests whether a scalar value is greater than or equal to this data column. (Inherited from DataColumn)
	vop_GreaterOrEqual_Rev(DataColumn, DataColumn)	Tests whether another data column is greater than or equal to this data column. (Inherited from DataColumn)
	vop_Increment	Applies the increment operator. (Inherited from DataColumn)
	vop_Lesser(AltaxoVariant, DataColumn)	Tests whether this data column is less than a scalar value. (Inherited from DataColumn)
	vop_Lesser(DataColumn, DataColumn)	Tests whether this data column is less than another data column. (Inherited from DataColumn)
	vop_Lesser_Rev(AltaxoVariant, DataColumn)	Tests whether a scalar value is less than this data column. (Inherited from DataColumn)
	vop_Lesser_Rev(DataColumn, DataColumn)	Tests whether another data column is less than this data column. (Inherited from DataColumn)
	vop_LesserOrEqual(AltaxoVariant, DataColumn)	Tests whether this data column is less than or equal to a scalar value. (Inherited from DataColumn)
	vop_LesserOrEqual(DataColumn, DataColumn)	Tests whether this data column is less than or equal to another data column. (Inherited from DataColumn)
	vop_LesserOrEqual_Rev(AltaxoVariant, DataColumn)	Tests whether a scalar value is less than or equal to this data column. (Inherited from DataColumn)
	vop_LesserOrEqual_Rev(DataColumn, DataColumn)	Tests whether another data column is less than or equal to this data column. (Inherited from DataColumn)
	vop_Minus	Applies the unary minus operator. (Inherited from DataColumn)
	vop_Modulo(AltaxoVariant, DataColumn)	Calculates the modulo of this data column with a scalar value. (Inherited from DataColumn)
	vop_Modulo(DataColumn, DataColumn)	Calculates the modulo of this data column with another data column. (Inherited from DataColumn)
	vop_Modulo_Rev(AltaxoVariant, DataColumn)	Calculates the modulo of a scalar value with this data column. (Inherited from DataColumn)
	vop_Modulo_Rev(DataColumn, DataColumn)	Calculates the modulo of another data column with this data column. (Inherited from DataColumn)
	vop_Multiplication(AltaxoVariant, DataColumn)	Multiplies this data column by a scalar value. (Inherited from DataColumn)
	vop_Multiplication(DataColumn, DataColumn)	Multiplies another data column to this data column (item by item). (Inherited from DataColumn)
	vop_Multiplication_Rev(AltaxoVariant, DataColumn)	Multiplies a scalar value by this data column in reverse operand order. (Inherited from DataColumn)
	vop_Multiplication_Rev(DataColumn, DataColumn)	Multiplies another data column with this data column in reverse operand order. (Inherited from DataColumn)
	vop_Not	Applies the logical NOT operator. (Inherited from DataColumn)
	vop_Or(AltaxoVariant, DataColumn)	Applies a logical OR between this data column and a scalar value. (Inherited from DataColumn)
	vop_Or(DataColumn, DataColumn)	Applies a logical OR between this data column and another data column. (Inherited from DataColumn)
	vop_Or_Rev(AltaxoVariant, DataColumn)	Applies a logical OR between a scalar value and this data column in reverse operand order. (Inherited from DataColumn)
	vop_Or_Rev(DataColumn, DataColumn)	Applies a logical OR between another data column and this data column in reverse operand order. (Inherited from DataColumn)
	vop_Plus	Applies the unary plus operator. (Inherited from DataColumn)
	vop_ShiftLeft(AltaxoVariant, DataColumn)	Shifts this data column left by a scalar value. (Inherited from DataColumn)
	vop_ShiftLeft(DataColumn, DataColumn)	Shifts this data column left by the values of another data column. (Inherited from DataColumn)
	vop_ShiftLeft_Rev(AltaxoVariant, DataColumn)	Shifts a scalar value left by this data column in reverse operand order. (Inherited from DataColumn)
	vop_ShiftLeft_Rev(DataColumn, DataColumn)	Shifts another data column left by this data column in reverse operand order. (Inherited from DataColumn)
	vop_ShiftRight(AltaxoVariant, DataColumn)	Shifts this data column right by a scalar value. (Inherited from DataColumn)
	vop_ShiftRight(DataColumn, DataColumn)	Shifts this data column right by the values of another data column. (Inherited from DataColumn)
	vop_ShiftRight_Rev(AltaxoVariant, DataColumn)	Shifts a scalar value right by this data column in reverse operand order. (Inherited from DataColumn)
	vop_ShiftRight_Rev(DataColumn, DataColumn)	Shifts another data column right by this data column in reverse operand order. (Inherited from DataColumn)
	vop_Subtraction(AltaxoVariant, DataColumn)	Subtracts a scalar value from this data column. (Inherited from DataColumn)
	vop_Subtraction(DataColumn, DataColumn)	Subtracts another data column from this data column (item by item). (Inherited from DataColumn)
	vop_Subtraction_Rev(AltaxoVariant, DataColumn)	Subtracts this data column from a scalar value. (Inherited from DataColumn)
	vop_Subtraction_Rev(DataColumn, DataColumn)	Subtracts this data column from another data column. (Inherited from DataColumn)
	vop_True	Evaluates whether this column should be treated as logically true. (Inherited from DataColumn)
	vop_Xor(AltaxoVariant, DataColumn)	Applies an exclusive OR between this data column and a scalar value. (Inherited from DataColumn)
	vop_Xor(DataColumn, DataColumn)	Applies an exclusive OR between this data column and another data column. (Inherited from DataColumn)
	vop_Xor_Rev(AltaxoVariant, DataColumn)	Applies an exclusive OR between a scalar value and this data column in reverse operand order. (Inherited from DataColumn)
	vop_Xor_Rev(DataColumn, DataColumn)	Applies an exclusive OR between another data column and this data column in reverse operand order. (Inherited from DataColumn)

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Events

	Name	Description
	Changed	Fired when something in the object has changed, and the object is not suspended. (Inherited from SuspendableDocumentNodeBase)
	TunneledEvent	The event that is fired when the object is disposed. First argument is the sender, second argument is the original source, and third argument is the event arg. (Inherited from SuspendableDocumentNodeBase)

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Fields

	Name	Description
	_accumulatedEventData	Holds the accumulated change data. (Inherited from SuspendableDocumentLeafNodeWithSingleAccumulatedDataT)
	_parent	The parent object this instance belongs to. (Inherited from SuspendableDocumentNodeBase)

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Extension Methods

	Name	Description
	SetColumnFromFractionalIndex	Fills destination column with values from an original column by help of a fractional index. (Defined by MergeTables)
	ShowRenameColumnDialog	Asks for a new name and then renames the selected data column or property column. (Defined by ColumnCommands)
	ToHorzMatrix	This returns a read and writeable, horizontal oriented matrix of a DoubleColumn (Defined by DataColumnWrapper)
	ToROVector	This returns a read-only vector of a INumericColumn (Defined by DataColumnWrapper)
	ToROVector	This returns a read-only vector of a INumericColumn (Defined by DataColumnWrapper)
	ToROVector	This returns a read-only vector of a INumericColumn (Defined by DataColumnWrapper)
	ToROVectorCopy	This returns a read-only vector of a INumericColumn, but the data are copyied before. Thus, if you change the data into the numeric column, the data of the returned vector is not influenced. (Defined by DataColumnWrapper)
	ToVector	This returns a read and writeable vector of a DoubleColumn (Defined by DataColumnWrapper)
	ToVector	This returns a read and writeable vector of a DoubleColumn (Defined by DataColumnWrapper)
	ToVector	This returns a read and writeable vector of a DoubleColumn (Defined by DataColumnWrapper)
	ToVertMatrix	This returns a read and writeable, vertical oriented matrix of a DoubleColumn (Defined by DataColumnWrapper)

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Reference

Altaxo.Data Namespace