问题
I have been trying to make a test object that has a string property visible to the visual binding form. The component is registered with the appropriate properties. Using XE8 and Firemonkey.
I can get it to show on the visual binder by selecting it using the hide show elements, however I cannot get it to bind the Foo string to a TEdit text property, the readonly (which does nothing yet) will bind to the Text Property.
- how do I get it show in it with default class visibility
- why doesn't the Foo string bind to the text property
The help files are a little thin on this. I guessing I'm missing something really simple here.
Object Code is below.
Thanks.
unit TestOBj;
interface
uses
System.Classes, System.SysUtils, System.StrUtils, Data.Bind.Components;
Type
TMyLBObject = Class (TComponent)
private
fFooString:String;
FReadOnly: Boolean;
procedure SetReadOnly(const Value: Boolean);
procedure SetFooString(const Value: String);
protected
function CanObserve(const ID: Integer): Boolean; override;
procedure ObserverAdded(const ID: Integer; const Observer: IObserver); override;
procedure ObserverToggle(const AObserver: IObserver; const Value: Boolean);
published
property Foo:String read FFooString write SetFooString;
property ReadOnly:Boolean read FReadOnly write SetReadOnly;
End;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Test', [TMyLBObject]);
end;
{ TMyLBObject }
function TMyLBObject.CanObserve(const ID: Integer): Boolean;
begin
Result := False;
if ID = TObserverMapping.EditLinkID then
Result := True;
if ID = TObserverMapping.ControlValueID then
Result := True;
end;
procedure TMyLBObject.ObserverAdded(const ID: Integer;
const Observer: IObserver);
begin
if ID = TObserverMapping.EditLinkID then
Observer.OnObserverToggle := ObserverToggle;
end;
procedure TMyLBObject.ObserverToggle(const AObserver: IObserver;
const Value: Boolean);
var
LEditLinkObserver: IEditLinkObserver;
LSaveReadOnly: Boolean;
begin
if Supports(AObserver, IEditLinkObserver, LEditLinkObserver) then
begin
if Value then
begin
LSaveReadOnly := ReadOnly;
if LEditLinkObserver.IsReadOnly then
ReadOnly := True;
FReadOnly := LSaveReadOnly;
end
else
if not (csDestroying in ComponentState) then
ReadOnly := FReadOnly;
end;
end;
procedure TMyLBObject.SetFooString(const Value: String);
begin
FFooString := Value;
end;
procedure TMyLBObject.SetReadOnly(const Value: Boolean);
begin
FReadOnly := Value;
end;
initialization
RegisterClass(TMyLBObject);
RegisterObservableMember(TArray<TClass>.Create(TMyLBObject), 'Foo', 'FMX');
finalization
UnRegisterObservableMember(TArray<TClass>.Create(TMyLBObject));
end.
回答1:
Your TMyLBObject
component does not have an [ObservableMember('Foo')]
attribute.
type
[ObservableMember('Foo')] // <-- add this
TMyLBObject = Class (TComponent)
...
published
property Foo:String read FFooString write SetFooString;
...
End;
See the example in the documentation:
Tutorial: Creating LiveBindings-Enabled Components.
Which includes this note:
The ObservableMember attribute will be used by LiveBindings components to generate expressions. RegisterObserverableMember() will be used at design time to inform the LiveBindings Designer.
来源:https://stackoverflow.com/questions/31963141/delphi-making-a-component-visible-to-live-binding