Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>This more generic routine works either with a Form or Frame (updated to use a subclass for the new control):</p> <pre><code>function ReplaceControlEx(AControl: TControl; const AControlClass: TControlClass; const ANewName: string; const IsFreed : Boolean = True): TControl; begin if AControl = nil then begin Result := nil; Exit; end; Result := AControlClass.Create(AControl.Owner); CloneProperties(AControl, Result);// copy all properties to new control // Result.Left := AControl.Left; // or copy some properties manually... // Result.Top := AControl.Top; Result.Name := ANewName; Result.Parent := AControl.Parent; // needed for the InsertControl &amp; RemoveControl magic if IsFreed then FreeAndNil(AControl); end; function ReplaceControl(AControl: TControl; const ANewName: string; const IsFreed : Boolean = True): TControl; begin if AControl = nil then Result := nil else Result := ReplaceControlEx(AControl, TControlClass(AControl.ClassType), ANewName, IsFreed); end; </code></pre> <p>using this routine to pass the properties to the new control </p> <pre><code>procedure CloneProperties(const Source: TControl; const Dest: TControl); var ms: TMemoryStream; OldName: string; begin OldName := Source.Name; Source.Name := ''; // needed to avoid Name collision try ms := TMemoryStream.Create; try ms.WriteComponent(Source); ms.Position := 0; ms.ReadComponent(Dest); finally ms.Free; end; finally Source.Name := OldName; end; end; </code></pre> <p>use it like:</p> <pre><code>procedure TFrame1.AfterConstruction; var I: Integer; NewEdit: TMyEdit; begin inherited; NewEdit := ReplaceControlEx(Edit1, TMyEdit, 'Edit2') as TMyEdit; if Assigned(NewEdit) then begin NewEdit.Text := 'My Brand New Edit'; NewEdit.Author := 'Myself'; end; for I:=0 to ControlCount-1 do begin ShowMessage(Controls[I].Name); end; end; </code></pre> <p><strong>CAUTION</strong>: If you are doing this inside the AfterConstruction of the Frame, beware that the hosting Form construction is not finished yet.<br> Freeing Controls there, might cause a lot of problems as you're messing up with Form controls housekeeping.<br> See what you get if you try to read the new Edit Caption to display in the ShowMessage...<br> In that case you would want to use<br> ...ReplaceControl(Edit1, 'Edit2', <strong>False</strong>)<br> and then do a<br> ...FreeAndNil(Edit1)<br> later.</p>
    singulars
    1. This table or related slice is empty.
    1. PORemove and Replace a visual component at runtime
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USFrançois
    1. USFrançois
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PORemove and Replace a visual component at runtime
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThis won't help, since he wanted to replace the TEdit with another type of component. (some descendent) For the rest this is exactly the same the first answer, except that you wrapped it into a function. Maybe that the AfterConstruction tip is usefull, though.
      singulars
      1. PO
      1. USLoesje
    2. COActually, the same idea works with a subclass, see updated version. Got me not reading carefully though, as I had missed the "subclassed"...
      singulars
      1. PO
      1. USFrançois
    3. CO2 further comments: 1. It's best not to drill down to IsertControl/RemoveControl unless really necessary. SetParent does all that's needed. 2. And I beg to differ about being the same: it is much more generic and flexible using the class factory approach with TControlClass.
      singulars
      1. PO
      1. USFrançois
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload