Tue, 12 Apr 2005 03:44:23 GMT

during design time fine, but during runtime propeties without effect

I add two properties to the control.
DataSource and a String for the column name. The combobox should be filled
with all records of the dataset which is linke to the datasource.

Problem:
During the design time everything works fine -> the Item consist of the
records
But during the runtime the set properties has no effect -> the list is
empty.

That's my first component and I think this is a very stupid mistake, but I
can't find the problem.

//--------------------------------------------------------------------------
-

#include <vcl.h>

#pragma hdrstop

#include "DBComboBoxList.h"
#pragma package(smart_init)
//--------------------------------------------------------------------------
-
// Mit ValidCtrCheck wird sichergestellt, da? die erzeugten Komponenten
// keine rein virtuellen Funktionen besitzen.
//

static inline void ValidCtrCheck(TDBComboBoxList *)
{
    new TDBComboBoxList(NULL);

Quote
}

//--------------------------------------------------------------------------
-
__fastcall TDBComboBoxList::TDBComboBoxList(TComponent* Owner)
    : TCustomComboBox(Owner)
{
    FDataLink = new TFieldDataLink();
    FDataLink->Control = this;
Quote
}

//--------------------------------------------------------------------------
-
namespace Dbcomboboxlist
{
    void __fastcall PACKAGE Register()
    {
         TComponentClass classes[1] = {__classid(TDBComboBoxList)};
         RegisterComponents("Cratemaker", classes, 0);
    }
Quote
}

//--------------------------------------------------------------------------
-

__fastcall TDBComboBoxList::~TDBComboBoxList()
{
    FDataLink->Control = NULL;
    FDataLink->OnUpdateData = NULL;
    delete FDataLink;

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}

AnsiString __fastcall TDBComboBoxList::GetDataField(){
    return FDataLink->FieldName;
Quote
}

TDataSource* __fastcall TDBComboBoxList::GetDataSource(){
    return FDataLink->DataSource;

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}

void __fastcall TDBComboBoxList::SetDataField(AnsiString FieldName){
    FDataLink->FieldName = FieldName;
    Caption = "";
    InitItems();

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}

void __fastcall TDBComboBoxList::SetDataSource(TDataSource *datasource){
    if ( datasource != NULL ){
        datasource->FreeNotification(this);
        if (Items != NULL)
        {
          Items->Clear();
        }
    }
    FDataLink->DataSource = datasource;

Quote
}

/**
    The method load the items by reading from datasource
*/
void __fastcall TDBComboBoxList::InitItems()
{
    if (FDataLink->FieldName != NULL &&
        FDataLink->DataSource != NULL &&
        Items != NULL)
    {
        Items->Clear();
        TDataSet* dataSet = FDataLink->DataSource->DataSet;
        if (dataSet != NULL)
        {
            // iterate over all records from dataset
            while (!dataSet->Eof)
            {

Items->Add(dataSet->FieldByName(FDataLink->FieldName)->AsString);
                dataSet->Next();
            }
        }
        else Items->Add("DEBUG: DatSet empty");
    }

Quote
}