Combobox中每個item都顯示hint - Delphi K.Top 討論區

發表時間：2008-09-03 23:18:10

IP:59.115.xxx.xxx 訂閱

因為ComboBox 沒有MouseMove可用,
所以我用Mouse Hook 控制.
如下的程式碼參考看...

[code cpp]
// .cpp
// 新增2個物件: ComboBox , Label
//---------------------------------------------------------------------------
#include
#pragma hdrstop
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
int xpos;
static HHOOK hHook;
LRESULT CALLBACK hookProc(int nCode, WPARAM wParam, LPARAM lParam);
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
: TForm(Owner)
{
}
//---------------------------------------------------------------------------
LRESULT CALLBACK hookProc(int iCode, WPARAM wParam, LPARAM lParam)
{
TEventMsg msg;
if (iCode < 0)
{
//必須將消息傳遞到消息鏈的下一個接受單元
return CallNextHookEx(hHook,iCode,wParam,lParam);
}
else if (iCode == HC_ACTION)
{
msg = *((TEventMsg*)(lParam));
if (msg.message == WM_MOUSEMOVE )
{
POINT P;
::GetCursorPos(&P);
::ScreenToClient(Form1->ComboBox1->Handle,&P);
RECT r;
::GetClientRect(Form1->ComboBox1->Handle,&r);
if(Form1->DropDown_fg && P.x< (int)xpos && P.x > (int)r.left && P.y < ((int)r.top (int)r.bottom) (Form1->ComboBox1->ItemHeight*Form1->ComboBox1->DropDownCount) && P.y > (int)r.top (int)r.bottom)
Form1->Label1->Visible=true;
else Form1->Label1->Visible=false;
}
}
return NULL;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ComboBox1DrawItem(TWinControl *Control, int Index,
TRect &Rect, TOwnerDrawState State)
{
((TComboBox *)Control)->Canvas->FillRect(Rect);
((TComboBox *)Control)->Canvas->TextOut(Rect.Left, Rect.Top 2, ((TComboBox *)Control)->Items->Strings[Index]);
if(State.Contains(odFocused))
{
Label1->Top=Rect.top 50;
Label1->Left=ComboBox1->Left xpos 18;
Label1->Caption=((TComboBox *)Control)->Items->Strings[Index];
Form1->Caption=((TComboBox *)Control)->Items->Strings[Index];
}
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
ComboBox1->ItemIndex=0;
if(ComboBox1->Items->Count>ComboBox1->DropDownCount)
xpos=ComboBox1->Width-16;
else
xpos=ComboBox1->Width;
Label1->Visible=false;
Label1->Color=(TColor)RGB(255,255,153);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ComboBox1DropDown(TObject *Sender)
{
DropDown_fg=true;
hHook = ::SetWindowsHookEx(WH_JOURNALRECORD,(HOOKPROC)hookProc,HInstance,0);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormDestroy(TObject *Sender)
{
if (hHook != 0)
{
UnhookWindowsHookEx(hHook);
hHook = 0;
}
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ComboBox1CloseUp(TObject *Sender)
{
Label1->Visible= false;
DropDown_fg=false;
UnhookWindowsHookEx(hHook);
hHook = 0;
}
//---------------------------------------------------------------------------
// .h
public:
bool DropDown_fg;[/code]

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yangshuh