mainunit.cpp

《delphi 7.0_8.0课程设计与系统开发案例》随书代码

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

#include <vcl.h>
#pragma hdrstop

#include "MainUnit.h"
#include "DataMoudalUnit.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::CheckBox1Click(TObject *Sender)
{
 DataModule1->Table2->Filtered =true;

  // If the number changed while the box is unchecked, DM1->OrdersFilterAmount
  // won't know about it.  The Edit1Change procedure will set the value and
  // apply the filter.
  if (CheckBox1->Checked)
    Edit1Change(NULL); // ...to make sure the value is set.
}
//---------------------------------------------------------------------------


void __fastcall TForm1::Edit1Change(TObject *Sender)
{
  // We must insure that Edit1->Text is not blank, or an exception will
  // be thrown when the user clears the contents of the Edit.

  if (CheckBox1->Checked && Edit1->Text != "") {
    try {
      // Attempt to set the variable on DM1 that holds the filter amount.
      DataModule1->OrdersFilterAmount = StrToFloat(Form1->Edit1->Text);

      // Refreshing SQLOrders will cause DM1->SQLOrdersFilterRecord to be
      // called once for each orders record for the current Customer. 
      DataModule1->Table2->Refresh();
    }
    catch (EConvertError* exc) {
        // This happens before DM1->SQLOrders->Refresh() if the user typed in a
        // non-numeric value, thus preventing it from trying to use an invalid
        // value to filter itself, which would raise an exception once for
        // each record displayed.
        throw Exception("Threshold Amount must be a number.");
    }
  }
}

// Set the navigator to the Customer Datasource.
//

}
//---------------------------------------------------------------------------