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TByteField class

In unit DB

Field class for 8-bit unsigned integer data.

Declaration

pascal
TByteField = class(TLongintField)

Inheritance

  1. TByteField
  2. TLongintField
  3. TNumericField
  4. TField
  5. TComponent
  6. TPersistent
  7. TObject

Description

TByteField is instantiated when a dataset must manage a field with 8-bit unsigned data: the data type ftByte. It overrides some methods of TField to handle Byte data, and sets some of the properties to values for Byte data. It also introduces some methods and properties specific to integer data such as MinValue and MaxValue.

It should never be necessary to create an instance of TByteField manually, a field of this class will be instantiated automatically for each integer field when a dataset is opened.

See also

Methods

GetDataSizeprotected
CreatepublicCreate new instance of TByteField.

Inherited

From TLongintField (18)

CheckRange GetAsFloat GetAsInteger GetAsLargeInt GetAsLongWord GetAsString GetAsVariant GetText GetValue MaxValue MinValue SetAsFloat SetAsInteger SetAsLargeInt SetAsLongWord SetAsString SetVarValue Value

From TNumericField (9)

Alignment CheckTypeSize DisplayFormat EditFormat GetAsBoolean RangeError SetAsBoolean SetDisplayFormat SetEditFormat

From TField (127)

AccessError AsAnsiString AsBCD AsBoolean AsBytes AsCurrency AsDateTime AsExtended AsFloat AsInteger AsLargeInt AsLongint AsLongWord Assign AssignValue AsSingle AsString AsUnicodeString AsUTF8String AsVariant AsWideString AttributeSet Bind Calculated CanModify Change CheckInactive Clear ConstraintErrorMessage CurValue CustomConstraint DataChanged DataSet DataSize DataType DefaultExpression Destroy DisplayLabel DisplayName DisplayText DisplayWidth EditMask EditMaskPtr FieldDef FieldKind FieldName FieldNo FocusControl FreeBuffers GetAsAnsiString GetAsBCD GetAsBytes GetAsCurrency GetAsDateTime GetAsExtended GetAsLongint GetAsSingle GetAsUnicodeString GetAsUTF8String GetAsWideString GetCanModify GetClassDesc GetCurValue GetData GetDefaultWidth GetDisplayName GetIsNull GetNewValue GetOldValue GetParentComponent HasConstraints HasParent ImportedConstraint Index IsBlob IsIndexField IsNull IsValidChar KeyFields Lookup LookupCache LookupDataSet LookupKeyFields LookupList LookupResultField NewValue Notification Offset OldValue OnChange OnGetText OnSetText OnValidate Origin ParentField PropertyChanged ProviderFlags ReadOnly ReadState RefreshLookupList Required SetAsAnsiString SetAsBCD SetAsBytes SetAsCurrency SetAsDateTime SetAsExtended SetAsLongint SetAsSingle SetAsUnicodeString SetAsUTF8String SetAsVariant SetAsWideString SetData SetDataset SetDataType SetFieldType SetNewValue SetParentComponent SetParentField SetSize SetText Size Text Validate ValidChars Visible

From TComponent (69)

_AddRef _Release BeforeDestruction CanObserve ChangeName ComObject ComponentCount ComponentIndex Components ComponentState ComponentStyle DefineProperties DesignInfo DestroyComponents Destroying ExecuteAction FindComponent FreeNotification FreeOnRelease GetChildOwner GetChildParent GetChildren GetDeltaStreams GetEnumerator GetIDsOfNames GetNamePath GetObservers GetOwner GetTypeInfo GetTypeInfoCount iicrGetComponent InsertComponent Invoke IsImplementorOf Loaded Loading Name ObserverAdded Observers OnGetDeltaStreams Owner PaletteCreated QueryInterface ReadDeltaState ReadDeltaStream ReferenceInterface RemoveComponent RemoveFreeNotification RemoveFreeNotifications SafeCallException SetAncestor SetChildOrder SetDesigning SetDesignInstance SetInline SetName SetSubComponent Tag ToString TToStringNameMode UpdateAction Updated UpdateRegistry Updating ValidateContainer ValidateInsert ValidateRename VCLComObject WriteState

From TPersistent (4)

AssignTo FPOAttachObserver FPODetachObserver FPONotifyObservers

From TObject (37)

AfterConstruction CheckDisposed ClassInfo ClassName ClassNameIs ClassParent ClassType CleanupInstance DefaultHandler DefaultHandlerStr Dispatch DispatchStr Disposed DisposeOf Equals FieldAddress Free FreeInstance GetDisposed GetHashCode GetInterface GetInterfaceByStr GetInterfaceEntry GetInterfaceEntryByStr GetInterfaceTable GetInterfaceWeak GetLastCastErrorInfo InheritsFrom InitInstance InstanceSize MethodAddress MethodName newinstance QualifiedClassName StringMessageTable SystemHasExtendedRTTI UnitName

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.