Declare a variable of type TPanel and store a reference to your component in that variable. var Panel: TPanel; …. Panel := TPanel.Create(Self); You can then refer to the control using this variable. You will likely need to hold the variable as a member field of the form, or in an array, or indeed some … Read more
Most likely, the function tests if n belongs to the array: function InArray(A: TIntArray; n: Integer): boolean; var i: integer; begin result := false; for i := low(A) to high(A) do if A[i] = n then Exit(true); end; If you are using an old version of Delphi (<2009), you have to do function InArray(A: TIntArray; … Read more
hmmmm, turns out it was easier than thought. I simply looked at the GenerateJSON method and said ok, How can I use this method for XML. I then googled MempryStream to String and found this function function StreamToString(aStream: TStream): string; var SS: TStringStream; begin if aStream <> nil then begin SS := TStringStream.Create(”); try SS.CopyFrom(aStream, … Read more
Well you need to read up on FireDAC generally if you are completely unfamiliar with it, and look at the examples that come with recent versions of Delphi. But if you just want to know how to copy data from a FireDAC dataset that’s connected to a database to an in-memory table, you can do … Read more
The API for modifying linked resources is accessed with BeginUpdateResource, UpdateResource and EndUpdateResource. Consult the API documentation on MSDN to learn how to use these functions, and also refer to the example code on MSDN. Including large ZIP file resources in an executable, and frequently modifying them, seems to me like the sort of behaviour … Read more
bitblt(Masterbitmap.Canvas.handle, 0, 0, XPixel, YPixel, bitmap.Canvas.handle, 0, 0, srcand); you explicitly called Masterbitmap.Canvas.Lock, however you didn’t call bitmap.Canvas.Lock (so you can loose the canvas handle anytime within this call…) Additionally, you need to consider thread safety within GDI itself: Sharing of any GDI objects between different threads should be avoided at all cost. For example … Read more
The following code, without an OnKeyUp handler, does what you seem to want type TMyDBGrid = class(TDBGrid); procedure TForm1.DBGrid1KeyDown(Sender: TObject; var Key: Word; Shift: TShiftState); begin if Key = VK_Tab then begin Key := 0; if ssShift in Shift then DBGrid1.SelectedIndex := DBGrid1.SelectedIndex + 1 else begin if TMyDBGrid(DBGrid1).Col = 1 then begin // The … Read more
An Invalid Pointer exception is thrown by the memory manager when it tries to free invalid memory. There are three ways this can happen. The most common is because you’re trying to free an object that you’ve already freed. If you turn on FastMM’s FullDebugMode, it will detect this and point you directly to the … Read more
I am trying to answer the question from a database point of view. You have a table with one or more rows and every row has in the four columns either an ‘A’ or something else. For a given row (or for many rows) you want to get the number of columns that have an … Read more
… if somehow we can set the database Alias to ADO connection … Just take a look at the source code of Delphi’s BDE and ADO support (in e.g. DBTables.Pas and ADOInt.Pas + ADODB.Pas and you will soon see that they are as different as chalk and cheese. You have no hope of e.g. using … Read more
You added in the comments that you are setting FForm to be equal to a valid existing form. If so, you may not need to create anything: procedure TMyComp.Execute_FormShowModal; var frm: TFormUser; begin frm:= TFormUser(FForm); frm.BtnOK.Enabled:=False; frm.ShowModal; //frm.Free; end; This assumes that this valid instance you are referring to is declared type TFormUser = class(TForm) … Read more
Raize Components has a TRzDbComboBox where you have separate lists for Items and Values. From the help: The TRzDBComboBox does support a Values property, which can be used to define a list of associated values to be stored in the selected database field instead of the string values maintained in the Items list. For example, … Read more
When you wish to modify data from an external object that is linked to your object (you have a reference to it stored) I think it might be best to use approach which I named “Property forwarding”. Now basically what you do in such approach is to define a property in your base object that … Read more
var olddir: string; //global variable procedure olddiris(name:string); begin if name=”trick” then olddir:= ‘c:\program files\’+name; end; procedure MyGetPath(name:string); var options : TSelectDirOpts; begin OldDirIs(name); //returns olddir if FileCtrl.SelectDirectory(OldDir,options,0) then ShowMessage(‘i got it’); end; procedure TForm1.Button1Click(Sender: TObject); begin Mygetpath(‘trick’); end; This code runs without error… (Note: changed GetPath -> MyGetPath; added “\” to ‘c:\program files’) If the … Read more
Here a customized form-class with implemented non-sizeable borders sizing and possibility to disable sizing for specified edges. Also it supports double clicks on borders to toggle between two rectangle-boundaries: AutoSizeRect to values of which form sides getting moved on dblclick and SavedSizeRect into which values form side coordinates saved before changing. So AutoSizeRect could be … Read more