能否让一个TrackBar显示有两个滑块？？

[lxj1984]

我现在需要一个功能，用滑块限定范围，需要在一个TrackBar中两个滑块，请问能不能实现？？我找了半天也没有找到相关选项

还有个小问题，怎样在上面显示相关数值？？

[BlueDeepOcean]

两个滑块的概念不清楚，看下面的例子，一个是指示滑块，另一个是蓝色进程条：

Form上放置两个Timer，时间分别为140和420，现在在各自Timer的OnTimer中分别处理指示滑块和蓝色进程条：

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

#include <vcl.h>
#pragma hdrstop

#include "Unt_TrackBar.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
Teg_TrackBar *eg_TrackBar;

int Block,Pos;
//---------------------------------------------------------------------------
__fastcall Teg_TrackBar::Teg_TrackBar(TComponent* Owner)
: TForm(Owner)
{
TrackBar->TickMarks = tmBoth;
TrackBar->TickStyle = tsNone;
TrackBar->Height = 25;

BlockTimer->Interval = 140;
PositionTimer->Interval = BlockTimer->Interval * 3;
}
//---------------------------------------------------------------------------
void __fastcall Teg_TrackBar::BlockMove(TObject *Sender)
{
if ((bool)Block)
{
TrackBar->SelStart ++;

if (TrackBar->SelEnd < TrackBar->Max)
Block = 1;
else
Block = 0;
}
else
{
if (TrackBar->SelStart > TrackBar->Min)
Block = 0;
else
Block = 1;

TrackBar->SelStart --;
}
TrackBar->SelEnd = TrackBar->SelStart + 2;
}
//---------------------------------------------------------------------------
void __fastcall Teg_TrackBar::PositionMove(TObject *Sender)
{
if ((bool)Pos)
{
TrackBar->Position ++;

if (TrackBar->Position < TrackBar->Max)
Pos = 1;
else
Pos = 0;
}
else
{
if (TrackBar->Position > TrackBar->Min)
Pos = 0;
else
Pos = 1;

TrackBar->Position --;
}
}
//---------------------------------------------------------------------------

[BlueDeepOcean]

另外，你可以参考：
..\Program Files\Borland\CBuilder5\Examples\Apps\RichEdit
文件夹下面有关RichEdit的例子，其中模拟了Word风格的标尺，那就是利用TLabel组件完成标识块的模拟的，你可以参考它并从其中获得启示。其实不难，那个范围就是Label->Left和TrackBar->Width和TrackBar->Max之间的关系嘛。

[lxj1984]

非常感谢，不过我看了下，并不是我想要的。以下是示意

======▊==========▊=========

我想要这样显示，取得两块滑块中间的值。我试着想用两个TrackBar重叠，不过下面的会被遮住，并不能显示两个

[lxj1984]

谢谢，我用的D版，里面的HELP,EXAMPLE全没有.....

[BlueDeepOcean]

我都说了，另一个用TLabel代替的。很简单的，你再好好看看我上面说得。给你的例子我知道不符你的要求，那只是一个模拟状态条和滑块之间的关系的例子。

[lxj1984]

我这没有Examples，不知道你说的是怎样，不过我仔细看了你的话，也看了Word的滑动条，不知道你说的Label是不是用来标识滑动条上的数字的？？我实在是想不出来，怎样才能在一条滑动条上，显示出两个滑块？？还是说，让Label显示为类似滑块的形状，然后在鼠标事件中计算值后在滑动条上移动模拟？？

[BlueDeepOcean]

对，就是那样。

[lxj1984]

谢谢

“给出来吧，现在的程序员，哎……”
我想，你误会了.....

[真如实观]

同意上面的做法.

[BlueDeepOcean]

给出来吧，现在的程序员，哎……

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

/*
利用TPanel完成对TTrackBar另一个滑块的模拟
*/

#include <vcl.h>
#pragma hdrstop

#include "Unt_SimulateTwoBlock.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
Teg_SimulateTwoBlocks *eg_SimulateTwoBlocks;

TPoint *p;
bool IsClick;
int oldPos;
//---------------------------------------------------------------------------
__fastcall Teg_SimulateTwoBlocks::Teg_SimulateTwoBlocks(TComponent* Owner)
: TForm(Owner)
{
TrackBar->TickMarks = tmBoth;

Panel->Height = 20;
Panel->Width = 9;
Panel->Left = TrackBar->Left + TrackBar->ClientRect.Left + 7; //可变调整系数(1)
Panel->Top = TrackBar->Top + TrackBar->ClientRect.Top + 10; //可变调整系数(2)
Panel->Caption = "";

p = new TPoint;

oldPos = Panel->Left;
}
//---------------------------------------------------------------------------
void __fastcall Teg_SimulateTwoBlocks::PanelMouseDown(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
if (Button == mbLeft)
{
p->x = X;
p->y = Y;
IsClick = true;

Panel->Color = clSilver;
}
}
//---------------------------------------------------------------------------
void __fastcall Teg_SimulateTwoBlocks::PanelMouseMove(TObject *Sender,
TShiftState Shift, int X, int Y)
{
if (IsClick)
{
if (p->x > X)
if (Panel->Left - (p->x - X) > oldPos)
{
Panel->Left -= (p->x - X);

//TrackBar的滑块每移动12个像素Position加1

if ((Panel->Left - oldPos) % 12 == 0)
TrackBar->SelEnd = (Panel->Left - oldPos) / 12; //也就是TrackBar的Position
}
else
{
Panel->Left = oldPos;
TrackBar->SelEnd = 0;
}
if (p->x < X)
if (Panel->Left + (X - p->x) < (TrackBar->Left + TrackBar->ClientWidth - 14)) //可变微调系数(1)×2
{
Panel->Left += (X - p->x);
if ((Panel->Left - oldPos) % 12 == 0)
TrackBar->SelEnd = (Panel->Left - oldPos) / 12;
}
else
{
Panel->Left = TrackBar->Left + TrackBar->ClientWidth - 16; //可变微调系数(3)
TrackBar->SelEnd = TrackBar->Max;
}

//由StatusBar显示各个结果

StatusBar->Panels->Items[0]->Text = TrackBar->SelEnd;
StatusBar->Panels->Items[1]->Text = TrackBar->SelStart;
StatusBar->Panels->Items[2]->Text = TrackBar->SelEnd - TrackBar->SelStart;
}
}
//---------------------------------------------------------------------------
void __fastcall Teg_SimulateTwoBlocks::PanelMouseUp(TObject *Sender,
TMouseButton Button, TShiftState Shift, int X, int Y)
{
if (Button == mbLeft)
{
IsClick = false;

Panel->Color = clBtnFace;
}
}
//---------------------------------------------------------------------------
void __fastcall Teg_SimulateTwoBlocks::TrackBarChange(TObject *Sender)
{
TrackBar->SelStart = TrackBar->Position;

StatusBar->Panels->Items[0]->Text = TrackBar->SelEnd;
StatusBar->Panels->Items[1]->Text = TrackBar->SelStart;
StatusBar->Panels->Items[2]->Text = TrackBar->SelEnd - TrackBar->SelStart;
}
//---------------------------------------------------------------------------