//---------------------------------------------------------------------------    #include 
#pragma hdrstop    #include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
  : TForm(Owner)
{
  // 將值初始化為0
  Edit1->Text = "0";
  // 避免使用者輸入非數字字元
  Edit1->ReadOnly = TRUE;      // 不使用TUpDown自動更新Edit的方式, 因為這樣做只能增加/減少整數值
  UpDown1->Associate = NULL;
}
//---------------------------------------------------------------------------    void __fastcall TForm1::UpDown1ChangingEx(TObject *Sender,
      bool &AllowChange, short NewValue, TUpDownDirection Direction)
{
  float fValue;      if (Direction == updUp)
  {
    fValue = StrToFloat(Edit1->Text);
    fValue  = 0.5;
    Edit1->Text = FloatToStr(fValue);
  }
  else if (Direction == updDown)
  {
    fValue = StrToFloat(Edit1->Text);
    fValue -= 0.5;
    if (fValue < 0) fValue = 0;
    Edit1->Text = FloatToStr(fValue);
  }
}
//---------------------------------------------------------------------------    

引言: Hi Zard 你好 謝謝你詳細的範例解說,讓小弟我能了解UpDown的其他功能,執行時!正常穩定 我好奇的將增減量從0.5改成0.1郤發現會浮點全部的值域.請問有其它的方法 可以只顯示0,0.1,0.2,0.3,0.4,,,,10; float fValue; if (Direction == updUp) { fValue = StrToFloat(Edit1->Text); // fValue += 0.5; fValue +=0.1; //我好奇的改變為0.1 Edit1->Text = FloatToStr(fValue); }

void __fastcall TForm1::UpDown1ChangingEx(TObject *Sender,
      bool &AllowChange, short NewValue, TUpDownDirection Direction)
{
  float fValue;      if (Direction == updUp)
  {
    fValue = StrToFloat(Edit1->Text);
    fValue += 0.1;
    Edit1->Text = Format("%.1f", ARRAYOFCONST((fValue)));
  }
  else if (Direction == updDown)
  {
    fValue = StrToFloat(Edit1->Text);
    fValue -= 0.1;
    if (fValue < 0) fValue = 0;
    Edit1->Text = Format("%.1f", ARRAYOFCONST((fValue)));
  }
}