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Lajos Juhász

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Posts posted by Lajos Juhász


  1. Is the list correct in your example the first numbers are delimited with semicolon while the last is with comma. The easiest way to type this for me is:

     

    function ListContains(const PList: string; PNumber: integer): boolean;
    var
      sl: TStringList;
    begin
      sl:=TStringList.Create;
      try
        sl.Delimiter:=';';
        sl.DelimitedText:=StringReplace(PList, ',', ';', []);
        result:=sl.IndexOf(IntToStr(PNumber))<>-1;
    
      finally
        sl.Free;
      end;
    end;

     


  2. 16 minutes ago, Virgo said:

    There does not appear to be anything about progressbar in all this code... Unless  ProgressRunning and StopProgress variables have something to do with it.

    There is Form7.pb1.Position (a bad design to call directly from another unit as you cannot be sure that the procedure was called from that object) in the code however that's all we can see (besides the problems that the code full of Application.ProcessMessages also that should be avoided).


  3. 3 hours ago, Serge_G said:

    But I don't understand where I miss something because I have some memoryleaks

    ---------------------------

    It's very simple take a look at TImage.SetBitmap. The TImage object will assign the bitmap to the internal bitmap and will not take the ownership over of the parameter. You've to write:
     

    var 
      lbm: TBitmap;
    begin
      if OpenDialog1.Execute then
      begin
        Image1.Bitmap.LoadFromFile(OpenDialog1.FileName);
        lbm:=ConvertToGrayscale(image1.Bitmap);
        try
          Image2.Bitmap:=lbm;
        finally
          lbm.Free;
        end;
      end;  
    end;



     

    • Thanks 1

  4. Changing a DPI can also cause the following error message:

    ---------------------------
    Debugger Exception Notification
    ---------------------------
    Project XXXXX.exe raised exception class EReadError with message 'Stream read error'.
    ---------------------------
    Break   Continue   Help   Copy   
    ---------------------------
     

    With call stack: 

     

    :7538b522 KERNELBASE.RaiseException + 0x62
    :030f850a HookedRaiseException + $66
    :50162931 rtl280.@System@Classes@TReader@ReadBuffer$qqrio + 0x55

     

    After that the following exception is:

     

    First chance exception at $7538B522. Exception class EArgumentOutOfRangeException with message 'Argument out of range'. Process XXXXX.exe (17800)

    :7538b522 KERNELBASE.RaiseException + 0x62
    :030f850a HookedRaiseException + $66
    :50159093 rtl280.@System@Classes@TCollection@GetItem$qqri + 0x13
    :50159093 rtl280.@System@Classes@TCollection@GetItem$qqri + 0x13
    :50cc5327 vcl280.@Vcl@Controls@TControl@Resize$qqrv + 0x1b
    :50ccac1a ; C:\Program Files (x86)\Embarcadero\Studio\22.0\bin\vcl280.bpl
    :50ccacec vcl280.@Vcl@Controls@TWinControl@AlignControl$qqrp21Vcl@Controls@TControl + 0x68
    :50ccad47 vcl280.@Vcl@Controls@TWinControl@Realign$qqrv + 0x7
    :50ccf78c vcl280.@Vcl@Controls@TWinControl@ScaleForPPI$qqri + 0xc8
    :50ccf78c vcl280.@Vcl@Controls@TWinControl@ScaleForPPI$qqri + 0xc8
    :50ccf78c vcl280.@Vcl@Controls@TWinControl@ScaleForPPI$qqri + 0xc8
    :50ccf78c vcl280.@Vcl@Controls@TWinControl@ScaleForPPI$qqri + 0xc8
    :50ccf78c vcl280.@Vcl@Controls@TWinControl@ScaleForPPI$qqri + 0xc8
    :50ccf78c vcl280.@Vcl@Controls@TWinControl@ScaleForPPI$qqri + 0xc8
    :50ccf78c vcl280.@Vcl@Controls@TWinControl@ScaleForPPI$qqri + 0xc8
    :50e021a3 vcl280.@Vcl@Forms@TCustomForm@ScaleForPPIRect$qqrip18System@Types@TRect + 0x9b
    :fffffff8

     

    I don't have a test case for this as I put it on delay and re-testing with D12. Since Embarcadero thinks that it is not relevant to give a valid roadmap I promised to management at the company I work for that this should be fixed in Delphi 12. It's bad that Embarcadero follows the pattern from the past and now entered into the period when they hide every possible information.

     


  5. 16 minutes ago, David Heffernan said:

    No. The try finally here protects the lifetime management of the instantiated object, after the constructor has completed. An exception in the constructor will bubble up from here and never enter the try. This is a very very common misunderstanding. 

    Exactly what I was saying.

    In case you'write:

     

    try

      lObj:=TMyClass.create;

    finally

      lObj.Free;

    end;

    If the constructor raises the exception the RTL will clear that for you. However in case lObj as the name suggest is a local variable and you didn't assigned nil to it the value will be undefined and calling free on that reference can cause AV (in case you're not lucky that the value was nil).


  6. 13 minutes ago, David Heffernan said:

    Again, can somebody explain what problem is caused by raising in a constructor

    The only problem with it is that you've to write your code in form:

     

    lObj:=TMyClass.Create(....);
    try
    .....
    finally
      lObj.Free;
    end;

    Anyway you would write it in this form. So there is no problem. I believe it's just another phobia. People can be afraid from correct coding style but will happily use FreeAndNil everywhere in the code.


  7. You can use multiple try finally or>

    LA := nil;
    LB := nil;
    try
        LA := TRaiseOnMinus.Create( AInputA );	//<== PossibleRaise
        LB := TRaiseOnMinus.Create( AInputB );	//<== Possible Raise
    finally
      LA.Free;
      LB.Free;
    end;

    In this case before try LA and LB are both nil in case a constructor raises an exception it will still be NIL thus Free will do nothing.


  8. It's a missing property for TIDMessage class and it's not related to win10. Search in dfm files for DeleteTempFiles and remove the property. In Indy10 TIdMessage doesn't have that property. I don't know whenever it ever had that property (I've never worked with that old version of Indy).

     

    Edit: The only case when the application is compiled to use runtime packages. In that case if you provide the wrong bpls for Indy could result this error.


  9. I cannot reproduce this in a simple test program. What I did is placed a TFDMemTable into a form:

     

      object FDMemTable1: TFDMemTable
        FetchOptions.AssignedValues = [evMode]
        FetchOptions.Mode = fmAll
        ResourceOptions.AssignedValues = [rvSilentMode]
        ResourceOptions.SilentMode = True
        UpdateOptions.AssignedValues = [uvCheckRequired, uvAutoCommitUpdates]
        UpdateOptions.CheckRequired = False
        UpdateOptions.AutoCommitUpdates = True
        Left = 304
        Top = 224
        object FDMemTable1a: TIntegerField
          FieldName = 'a'
        end
        object FDMemTable1b: TStringField
          FieldName = 'b'
          Size = 150
        end
      end
     

    and a button with the following onclick event:

     

    procedure TForm1.Button1Click(Sender: TObject);
    begin
      if not FDMemTable1.Active then
        FDMemTable1.CreateDataSet
      else
      begin
    //    FDMemTable1.Open; <- There is no need to do this Active is true
        FDMemTable1.EmptyDataSet;
      end;
    
      FDMemTable1.Append;
      FDMemTable1['a']:=1;
      FDMemTable1['b']:='1';
      FDMemTable1.Append;
      FDMemTable1['a']:=2;
      FDMemTable1['b']:='2';
      FDMemTable1.Append;
      FDMemTable1['a']:=3;
      FDMemTable1['b']:='3';
      FDMemTable1.Append;
      FDMemTable1['a']:=4;
      FDMemTable1['b']:='4';
      FDMemTable1.Post;
    end;

    It's working with multiple clicks.


  10. In case you're connecting to remote servers you have to buy Enterprise or Architect version. Professional supports only local databases and doesn't include the source code for FD.

     

    Before you open the project you have to migrate your project using the included refind utility using the included FireDAC_Migrate_BDE.txt.


  11. 9 minutes ago, audi30tdi said:

    Is it easy to convert from Delphi7 with BDE to the nevest Delphi/Embarcadero version with FireDAC, or must I rewrite all my code??

    FireDAC was written to be replacement for the BDE and there is a script that converts the properties. It really depends the database and methods from BDE you are using in your code.

     

    Unfortunately if you're using persistent fields you will have to recreate them as most probably FD will require another class.

     

    (You can try to map the data types in the TFDConnection object to the old classes, however I like to keep mapping to minimum.)


  12. Maybe you should try the old way. Append the memtable and set the value for the fields. Depending if you have only couple of fields you can write an the assign statements otherwise use a for loop.

     

    Something like this should work (you're copying the structure thus the order of the fields should be the same):

     

    var

      i: integer;

     

    begin
      kbmMemTable.Append;

      for i:=0 to kbmMemTable.fieldCount-1 do

         kbmMemTable.fields.value:=myTEDBTable.fields.value;

    end;

     

     

     


  13. 7 hours ago, Qasim Shahzad said:

    Now Please guide why this is a bad idea. It reduces a lot of code duplication and we can add Form Creation procedure in a common library.

    When you're displaying the forms this way they are useless there are no input values to the form and the form doesn't produce any result. You're destroying the instance before the calling code could read the results back.

     

    I am aware that you can initialize the form in the formcreate and write the results back in formdestroy but that is a bad design.

    • Like 1
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