My Delphi program builds and compiles fine, however as soon as it is run in the debug mode, I get the following error;
Property ClientHeight does Not Exist
After looking through all of the .DFM file sources, in every form the code is there which is;
ClientHeight = 111
I'm not understanding where I go wrong here?
Your forms would have been saved with a newer version of Delphi. Unfortunately you will need to open each form in the IDE and save it again to clear the newer properties. There is a tool that can help you called DFMCheck (http://andy.jgknet.de/blog/ide-tools/dfmcheck/). This is an add on that will go through all of your forms and tell you about any problems with the forms that will only show up at runtime.
The reason why you are seeing the problem is this. Delphi saves the forms with all of the properties. It uses streaming to load the forms at runtime. When it tries to load a form with properties that don't exist then you will get an error like this as the streaming system is trying to set a property on a component when the property doesn't exist.
I know this is old thread, but hopefully this will help others that has this problem.
In cases like this where your class inheriteds from other and you know the properties are there, just re-publish them .Add a published section and add them again for example:
published
property ClientWidth;
property ClientHeight;
This then forces the compiler to compile these typeinfo for parts where the parents classes might have forward declarations and thus , resolve your issue.
Hope it helps somebody, took me 3 days to get to the solution eventually.
Same bug happens in modern Delphi (e.g. Rio 10.3) with FMX frames. After some investigation it revealed to be caused by tweaking TFrame inheritance. Example below:
type
// Declaration of custom type
TFrameEx = class(TFrame) .. {here I override a couple of methods} end;
// Causes a bug (described below)
TMyFrame = class(TFrameEx)
// Works fine
TMyFrame = class(TFrame)
Explanation:
Due to changed type, Delphi was unable to correctly choose TMyFrame type between FMX and VCL. So when the TMyFrame was opened in IDE it would ask to strip out FMX properties (non-existent in VCL, e.g. Size.Width) and add VCL properties (e.g. ClientWidth). When saved, that would make the TMyFrame buggy - it would show the "Property ClientHeight does Not Exist" error in runtime upon init.
Had similar bug. First you need a dfm file for your frame.
When you inherit a frame, the dfm file must starts with "inherited MyFrame: TFRameEx" and NOT "object MyFrame: TFrameEx". Without the inherited, when I did it, it was adding TForm properties and in the editor the frame had TForm events, in Delphi 10.3. So delphi really needs the dfm to find the right type. If you use the ide menu, it will be done automatically. New->Others->inheritables it will create the dfm with the inherited line, create a file with {$R *.dfm} in it and a line in the project source "unitname in '......pas' {MyFrame TFrame};" Or you can do it by hand.
As for the possibility of having multiple frames in the same unit, havent tested it myself but since the line is {$R *.dfm} it might be doable.
wanted it to be a comment for the solution of kromster but cant comment apparently.
In my case, I was inheriting TFrame that was save in Delphi 7, and I change the .dfm to resolve.
The first line: "object" frmMain: TfrmMain
I changed to "inherited", like this: inherited frmMain: TfrmMain
Related
I am porting over a VCL component to FMX. 99% of of the code is pure object pascal, so that works just fine - but i have a method which creates a form, poulates it with buttons and a text-box, and this quite simply doesnt work under FMX.
The whole point to creating the form manually and then populating it from code was to make sure it compiled under both VCL, LCL and FMX; and that it also displays just fine under iOS, Android and whatever platform is used.
But i keep getting "Resource /classname/ not found", where /classname/ is whatever classname i give my temporary form class.
Something as simple as this produces the error:
type
TMyDialogForm = Class(TForm);
procedure TForm1.Button1Click(Sender: TObject);
var
LDialog: TMyDialogForm;
begin
LDialog := TMyDialogForm.Create(application.MainForm);
try
LDialog.Caption := 'Yahoo!';
finally
LDialog.Free;
end;
end;
Since the error involves resource, I suspect that it is looking for some type of layout data. I have just started playing around with FMX, and i did notice that different platforms allow for different layouts. But I must admit I expected it to fall-back to the default theme, no matter what platform you target.
So -- how exactly do i create a form by code, populate it and display ut using Firemonkey without running into this kind of bug? It works perfectly fine under VCL and LCL, but FMX keeps going on about resources.
Please dont tell me all forms MUST be designed?
As #RemyLebeau answered a similar question in the delphi forum (How to create a TForm at runtime?):
You are calling the TForm constructor that invokes DFM streaming. The reason
it does not fail in non-FMX apps is because TCustomForm.Create() filters
out TForm specifically so it won't try to stream. In FMX, TCommonCustomForm.Create()
filters out TCommonCustomForm instead of TForm, which is why your TForm in
FMX is trying to stream itself.
Since you know that there is no DFM, you should be using the non-DFM constructor
instead, in both VCL and FMX:
FRM := TForm.CreateNew(Application);
So basically here is what I did:
I made a new FMHD Application and dropped a TTabControl and a Button on it. Then I designed an interface IFoo. To keep it simple, let's just pretend it only has one procedure:
type
IFoo = interface
['{D035-N07-M4773R-...}']
procedure makeTab(tc : TTabControl);
End;
I implemented this interface in a DLL. The DLL is loaded via LoadLibrary and exports a
function getFoo : IFoo;
MakeTab basically creates a TTabItem and sets tc as it's parent:
procedure TFoo.makeTab(tc : TTabControl);
var
tab
: TTabItem;
begin
tab := TTabItem.Create(tc);
tab.text := 'Hi, I am Tab';
tab.Parent := tc;
// ...
end;
If I forgot something, I am very sorry. I do not have the exact source in front of me at the moment.
This method is invoked when the Button on the form is pressed.
But nothing happens.
So I put this method into my TForm1 class. If I call it now, a tab is created.
So how can I create this tab (and several child components) from within the DLL on the application's main form?
The fundamental issue here is that you cannot share Delphi class types between modules using DLLs. The reason is that there will be multiple versions of what needs to be a single type. One version in the executable, and one version in each DLL that uses it.
This is the same well known issue that exists with the VCL and is the reason why runtime packages were developed. And that's your solution for FMX also. If you need to share Delphi class types between modules you need there to be one single definition of a type. And runtime packages are the mechanism that makes that possible.
So, stop using DLLs, move the code into a runtime package, make sure that the RTL and FMX are linked using runtime packages, and that problem will be solved.
Programming Environment: Delphi 6 and upwards
I am aware of the fact that since Delphi 6, custom components must have separate design- and run-time package. All run time features of the a component must therefore be in a separate unit and packaged separately to the component's design-time package.
My problem is the following: My component has code that needs to be run both when it is created on the form at run time and, additional code that needs to be run at design-time, when the component is placed on the form. I have managed to put the run time code into the separate run time unit, package it and deploy it successfully.
However, in the separate design-time module unit, how do I reference and add the design-time code that needs to be included into the component's create constructor during design-time, when the component gets placed onto the form?
You can separate design time behaviour from run time behaviour with
if [not] (csDesigning in ComponentState) then
But if your constructor code needs the DesignIDE design time package, e.g. from the units DesignEditors, DesignIntf, etc..., then I think you are stuck. Maybe some IOTA involvement can help. But since there does not seem to exist a notifier interface for the creation of components, that would require a custom IOTAFormEditor. Not that easy, if not impossible.
Why not use callbacks?
From your designtime package initialization code do this:
unit MyDsgnUnit;
interface
//TMyHook defined in AnImplUnit
TMyDesignHandlerObject = class
procedure MyMethod(Sender:TObject;ParentForm:TObject); { must match TMyHook }
end;
implementation
uses AnImplUnit, DesignUnitNamesHere;
procedure TMyDesignHandlerObject.MyMethod(Sender:TObject);
var
newObject:TMyComponent;
begin
newObject := TMyComponent(Sender);
DoSomethingThatneedsDesigntimeStuff(newObject);
end;
finalization
ADesignHandlerObject.Free;
initialization
ADesignHandlerObject := TMyDesignHandlerObject.Create;
AnImplUnit.AfterConstructionHook := TDesignHandlerObject.MyMethod;
and in your component do something like this:
unit AnImplUnit;
interface
type
TMyHook = procedure(Sender:TObject;ParentForm:TObject) of object;
var
AfterConstructionHook:TMyHook;
implementation
...
procedure TMyComponent.Create(AOwner:TComponent);
begin
inherited Create(AOwner);
DOMyStuff;
if Assigned(AfterConstructionHook)
AfterConstructionHook(Sender,Parent);
end;
Update Flushed out example more. There is no reason you can't add more parameters to the AfterConstructionHook, but since your reference to Sender is already of type TMyComponent, I don't see the point, when you can access everything public or protected, in TMyComponent(Sender) from within your hook function, and if you inherit locally (known as a protected-access class), you can access the protected stuff too.
Make sure your DPK defines a symbol of your choice, for example DESIGNTIME. Then you'll be able to use something like this to only include design-time units when needed:
uses Windows, Whatever, Something
{$IFDEF DESIGNTIME}
,DesignIntf
{$ENDIF}
;
Then to the same in your constructor code:
constructor TMyClass.Create(aOwner:TComponent);override;
begin
inherited;
{$IFDEF DESIGNTIME}
// I'm at design time.
{$ENDIF}
end;
When using this technique you should either use a separate DCU directory for your pacakge and your normal executable, or do a build each time you switch from the design time package to other projects. That's because Delphi will only re-build a DCU if the PAS has changed, when in this case the PAS doesn't tell the whole story, defined symbols also matter. If you have a DCU on disk that was compiled by Delphi while you were building your design time project, you might see a ToolsApi.DCU not found when trying to compile a normal project. Rebuilding re-compiles the DCU and makes the message go away. Just as well, if you re-compile (not re-build) the design time project after you built a normal project, your DCU might be stuck in it's non-DESIGNTIME state, leaving you without your special design-time behavior.
As long as your code does not require the IDE tools, like design interface and so on, then all you need to do is check the component flag and you can use it anywhere within the component, as follows...
procedure TNewEdit.Loaded;
begin
inherited;
if (csDesigning in ComponentState) then
ShowMessage('Designing')
else
ShowMessage('Running');
end;
However without really knowing what you are attempting to do, there are several doors left open... for example, if you want to change a property value at design time, and a different value at run time, then there are streaming issues you have to deal with.
Tool: Delphi 6 Pro
I created a new component in my main components package that is a descendant of TFrame using the Component -> New Component option. When I try to draw the component on a form during design time I get a "Resource {component class name} not found" error. I tried adding the line {$R *.dfm} to the component unit just after the "implementation" declaration and that didn't work. (I did recompile the host package first). I even tried copying over a DFM from another frame and then renaming everything to sync up with the main unit including the DFM file name itself. That didn't work either.
I want to have the TFrame descendant as a Component instead of just creating a new TFrame variant because I want to add properties to it that show up in the Property Editor at design time. Is there a way to make this work?
Thanks in advance.
Every once in a while when I am tweaking my TFrame classes (adding properties, methods, etc), the IDE gets confused and acts as if it thinks the frame is a form, complete with header/caption, borders, etc. Yet, clearly the class is declared as a TFrame descendent. Any ideas as to what causes this, how to prevent, and how to fix?
I'm using Delphi 2007 Pro. Also note (if it matters), the TFrame descendents are typically registered with the IDE (i.e. on the palette) via a design-time package.
Later: Additional "specifics": The frame that I'm having this problem with at the moment is, visually, a VERY basic TFrame (only change from brand new TFrame is size, and background color).
Here's its class declaration:
TBasePanel = class(TFrame)
private
FPanelManager: TPanelManager;
procedure SetPanelManager(const Value: TPanelManager);
protected
procedure Connect; virtual; abstract;
procedure Disconnect; virtual; abstract;
procedure Refresh; virtual;
procedure Requery; virtual; abstract;
published
property PanelManager: TPanelManager read FPanelManager write
SetPanelManager;
This frame is used as a base class for a number of others. I am usually editing it directly from the BPL project it belongs to (because all of these frames install to the palette), rather than as part of an EXE project, with related Forms open etc.
Also, "Embedded designer" is checked in Tools -> Options.
I am saving all DFM files as text rather than binary as well (if that matters at all).
I have encountered the same problem. The following steps solved the problem for us, it might also work for you:
in the IDE: close all forms that use the frame
open the frame, view as text (*.dfm)
the dfm probably begins with object MyFrame: TMyFrameClass
change this to inherited MyFrame: TMyFrameClass
I don't know what caused the problem.
Perhaps you had unchecked the 'Embedded designer' check box? (Tools | Options | Environment Options | VCL Designer). Then, indeed, your frame is shown at design time as a form (with caption, border etc.). Also a concrete code of your problematic TFrame descendant or more details about your case would help.
As far as I know, you have to have both the form and the frame open in the editor when you edit the frame. Else there can be update problems. Although I haven't seen this one.
But I gave up on frames a long time ago because I did not find them very reliable.
Right now I only use them for prototyping, creating a custom component (derived of a panel with the apropriate controls on it).
You may have to register custom module to the IDE
But your additional properties won't work well unless they are in ancestor class.
I have encounter a lot of problems with TFrame and finally came to such workaround that solves all my problems: I create and design frames visually, but use them only by hand-coding.
As a side effect my applications became smaller, because of less dfm-s.