Data.DB.TField Methods

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InheritedProtected

_AddRef	protected	Called when an application uses a component interface.
_Release	protected	Called when an application releases a component interface.
AccessError	protected	Creates en error message and returns an EDatabaseError exception.
AfterConstruction	public	Responds after the last constructor has executed.
Assign	public	Copies the Value property from another field component or assigns another object to the field component.
AssignTo	protected	Copies the properties of an object to a destination object.
AssignValue	public	Sets the field value using one of the AsInteger, AsBoolean, AsString or AsFloat properties.
AsyncSchedule	protected	Schedules asynch method calls.
BeforeDestruction	public	Performs any necessary actions before the first destructor is called.
BeginInvoke	public	Performs an asynchronous call to the method specified by either AProc or AFunc.
Bind	protected	Verifies whether the field is a lookup field and refreshes or validates the lookup list.
CanObserve	protected
Change	protected	Generates an OnChange event.
ChangeName	protected	Sets the private, internal storage for the Name property to the string passed in NewName.
CheckDisposed	protected
CheckInactive	protected	Checks whether the dataset is inactive or not.
CheckTypeSize	protected	Performs the validation of a field's size.
ClassInfo	public	Returns a pointer to the run-time type information (RTTI) table for the object type.
ClassName	public	Returns a string indicating the type of the object instance (as opposed to the type of the variable passed as an argument).
ClassNameIs	public	Determines whether an object is of a specific type.
ClassParent	public	Returns the type of the immediate ancestor of a class.
ClassType	public	Returns the class reference for the object's class.
CleanupInstance	public	Performs finalization on long strings, variants, and interface variables within a class.
Clear	public	Sets the value of the field to NULL.
CopyData	protected	Copies bytes of data from a given source to a given destination.
Create	public	Creates and initializes a field component.
DataChanged	protected	Generates a deFieldChange event.
DataSetMissingError	protected	Raises an EDatabaseError exception.
DefaultHandler	public	Provides the interface for a method that processes message records.
DefineProperties	protected	Designates a method for storing TField unpublished data on a stream such as a form file.
Destroy	public	Destroys an instance of TField.
DestroyComponents	public	Destroys all owned components.
Destroying	public	Indicates that the component and its owned components are about to be destroyed.
Dispatch	public	Calls message-handling methods for the object, based on the contents of the Message parameter.
DisposeOf	public	DisposeOf forces the execution of the destructor code in an object.
EndFunctionInvoke	public	Blocks the caller until the specified ASyncResult completes.
EndInvoke	public	Blocks the caller until the specified ASyncResult completes.
Equals	public	Checks whether the current instance and the Obj parameter are equal.
ExecuteAction	public	Executes an action.
FieldAddress	public	Returns the address of a published object field.
FieldValueError	protected	Raises an EDatabaseError exception.
FindComponent	public	Indicates whether a given component is owned by the component.
FocusControl	public	Forces a form's focus to the first data-aware component associated with the field object.
Free	public	Destroys an object and frees its associated memory, if necessary.
FreeBuffers	protected	Frees used buffers.
FreeInstance	public	Deallocates memory allocated by a previous call to the NewInstance method.
FreeNotification	public	Ensures that AComponent is notified that the component is going to be destroyed.
FreeOnRelease	public	Frees the interface reference for components that were created from COM classes.
GetAsAnsiString	protected	Returns the value of the field as an AnsiString.
GetAsBCD	protected	Returns the value of the field as a TBcd.
GetAsBoolean	protected	Returns the value of the field as a Boolean.
GetAsByteArray	protected	Returns the value of the field as a Variant holding unformatted data.
GetAsBytes	protected	Returns the value of the field as TBytes.
GetAsCurrency	protected	Returns the value of the field as a Currency.
GetAsDateTime	protected	Returns the value of the field as a TDateTime.
GetAsExtended	protected	Returns the value of the field as an Extended.
GetAsFloat	protected	Returns the value of the field as a Double.
GetAsInteger	protected	Returns the value of the field as an Integer.
GetAsLargeInt	protected	Returns the value of the field as an Int64.
GetAsLongWord	protected
GetAsSingle	protected	Returns the value of the field as a Single.
GetAsSQLTimeStamp	protected	Returns the value of the field as a TSQLTimeStamp.
GetAsSQLTimeStampOffset	protected	Returns the value of the field as a TSQLTimeStampOffset.
GetAsString	protected	Returns the value of the field as a string.
GetAsVariant	protected	Returns the value of the field as a Variant.
GetAsWideString	protected	Returns the value of the field as a WideString.
GetCanModify	protected	Returns whether the field's contents can be modified.
GetChildOwner	protected	Returns the owner of a child component being read from a stream.
GetChildParent	protected	Returns the parent or, if there is no parent, returns the owner of a child component being read from a stream.
GetChildren	protected	Enumerates all child components.
GetClassDesc	protected	Returns the abbreviated class name of the field.
GetData	public	Returns the unformatted data for the field.
GetDataSize	protected	Returns the number of bytes required to store a field component's value.
GetDefaultWidth	protected	Returns the field's default width.
GetDeltaStreams	protected
GetDisposed	protected	Getter for the Disposed property.
GetEnumerator	public	Returns a TComponent enumerator.
GetFieldNo	protected	Returns the ordinal position of the field's column in the underlying table or query result.
GetHasConstraints	protected	Returns whether field values are constrained.
GetHashCode	public	Returns an integer containing the hash code.
GetIDsOfNames	protected	Maps a single member and an optional set of argument names to a corresponding set of integer dispatch identifiers (dispIDs).
GetInterface	public	Retrieves a specified interface.
GetInterfaceEntry	public	Returns the entry for a specific interface implemented in a class.
GetInterfaceTable	public	Returns a pointer to a structure containing all of the interfaces implemented by a given class.
GetIOSize	protected	Returns the maximum number of bytes of the buffer.
GetIsNull	protected	Returns whether the field has data or not.
GetLookupListClass	protected	Returns the TLookupListClass data type.
GetNamePath	public	Returns a string used by the Object Inspector.
GetObservers	protected	Getter of Observers.
GetOwner	protected	Returns the owner of a component.
GetParentComponent	public	Returns the component which directs the loading and saving of the field.
GetSize	protected	Returns the size used in the definition of the physical database field for data types that support different sizes.
GetText	protected	Returns the field's value as a string.
GetTypeInfo	protected	Retrieves the type information for an object.
GetTypeInfoCount	protected	Returns the number of type information interfaces that an object provides (either 0 or 1).
GetWideText	protected	Returns the field's value as a UnicodeString.
HasParent	public	Returns true, indicating that field components act as part of a larger composite.
InheritsFrom	public	Determines the relationship of two object types.
InitInstance	public	Initializes a newly allocated object instance to all zeros and initializes the instance's virtual method table pointer.
InsertComponent	public	Establishes the component as the owner of a specified component.
InstanceSize	public	Returns the size in bytes of each instance of the object type.
Invoke	protected	Provides access to Automation properties and methods when the component wraps an Automation object.
IsBlob	public	Indicates whether the field represents the data in a binary large object (BLOB) field.
IsImplementorOf	public	Indicates whether the component implements a specified interface.
IsValidChar	public	Indicates whether a particular character is valid for the field.
Loaded	protected	Initializes the component after the form file has been read into memory.
MethodAddress	public	Returns the address of a class method by name.
MethodName	public	Returns the name of a class method by address.
NewInstance	public	Allocates memory for an instance of an object type and returns a pointer to that new instance.
Notification	protected	Notifies that components are to be inserted to or removed from a form.
ObserverAdded	protected
operator ()	public	C++ conversion of a TComponent into a System.Classes.IInterfaceComponentReference or a System.IInterface, depending on casting.
PaletteCreated	protected	Responds when the component is created from the component palette.
PropertyChanged	protected	Generates dataset change and layout change events.
QualifiedClassName	public	Returns the qualified name of the class.
QueryInterface	protected	Returns a reference to a specified interface if the current component supports that interface.
ReadState	protected	Reads the state of the component.
ReferenceInterface	public	Establishes or removes internal links that cause this component to be notified when the implementer of a specified interface is destroyed.
RefreshLookupList	public	Loads LookupList with all the values for LookupResultField that match distinct values of LookupKeyFields.
RemoveComponent	public	Removes a specified component specified from the component's Components list.
RemoveFreeNotification	public	Disables the destruction notification that was enabled by FreeNotification.
RemoveFreeNotifications	protected	Notifies all owned components of the owner component's imminent destruction.
SafeCallException	public	Handles exceptions in methods declared using the safecall calling convention.
SetAncestor	protected	Clears or sets csAncestor state in the component's ComponentState property.
SetAsAnsiString	protected	Sets the value of the field with the given AnsiString value.
SetAsBCD	protected	Sets the value of the field with the given TBcd value.
SetAsBoolean	protected	Sets the value of the field with the given Boolean value.
SetAsByteArray	protected	Sets the value of the field with the given unformatted data passed-in as a Variant.
SetAsBytes	protected	Sets the value of the field with the given unformatted data passed in as TBytes.
SetAsCurrency	protected	Sets the value of the field with the given Currency value.
SetAsDateTime	protected	Sets the value of the field with the given TDateTime value.
SetAsExtended	protected	Sets the value of the field with the given Extended value.
SetAsFloat	protected	Sets the value of the field with the given Double value.
SetAsInteger	protected	Sets the value of the field with the given Integer value.
SetAsLargeInt	protected	Sets the value of the field with the given Int64 value.
SetAsLongWord	protected
SetAsSingle	protected	Sets the value of the field with the given Single value.
SetAsSQLTimeStamp	protected	Sets the value of the field with the given TSQLTimeStamp value.
SetAsSQLTimeStampOffset	protected	Sets the value of the field with the given TSQLTimeStampOffset value.
SetAsString	protected	Sets the value of the field with the given string value.
SetAsVariant	protected	Attempts to set the value of the field with the given Variant value.
SetAsWideString	protected	Sets the value of the field with the given WideString value.
SetChildOrder	protected	Sets the visual ordering of a child control.
SetData	public	Assigns unformatted data to the field.
SetDataSet	protected	Adds the field to the specified dataset.
SetDataType	protected	Sets the data type of the field's contents.
SetDesigning	protected	Ensures that components inserted at design time have their design-mode flag set.
SetDesignInstance	protected	Ensures that components inserted at design time have their design-mode flag set.
SetFieldDefProps	public	Sets the properties of the specified FieldDef from this field's properties.
SetFieldKind	protected	Sets the field's kind according to the given parameter.
SetFieldProps	public	Sets this field's properties from the given definition.
SetFieldType	public	Provides the interface for a method that can set the DataType for the field.
SetInline	protected	Sets the csInline bit of the component's ComponentState property.
SetName	protected	Sets the value of the Name property.
SetParentComponent	public	Sets the parent component.
SetParentField	protected	Sets the TObjectField from which the field is derived.
SetSize	protected	Sets the field's size.
SetSubComponent	public	Identifies whether the component is a subcomponent.
SetText	protected	Sets the value of the field with the given string value.
SetVarValue	protected	Sets the value of the field with the given Variant value.
SetWideText	protected	Sets the value of the field with the given UnicodeString value.
ToString	public	Returns a string containing the class name.
UnitName	public	Returns the name of the unit where the class is defined.
UnitScope	public	Returns the class's unit scope.
UpdateAction	public	Updates the state of an action.
Updated	protected	Clears the csUpdating state in the component's ComponentState property when the component finishes updating.
UpdateRegistry	protected	Provides the interface for a method that adds type library and version information to the Registry on components that implement COM interfaces.
Updating	protected	Sets the csUpdating state in the component's ComponentState property.
Validate	public	Generates an OnValidate event.
ValidateContainer	protected	Determines whether an object can be inserted into a container.
ValidateInsert	protected	Provides the interface for a method that validates a child component before it is inserted.
ValidateRename	protected	Ensures that renaming an owned component does not create a name conflict.
WriteState	protected	Writes the state of the component.