請教各位先進 combobox下拉的寬度不夠寬 因為內容資料比較長，有沒有什麼函數或指令可以讓它變寬 請各位幫幫忙，謝謝！

引言:請教各位先進 combobox下拉的寬度不夠寬 因為內容資料比較長，有沒有什麼函數或指令可以讓它變寬 請各位幫幫忙，謝謝！

set DropDownCount for number of items in the drop down. For 寬, I think the standard combobox dropdown width is same as the width of the combobox itself.

因為內容的文字過長，不是要items 如 combobox.with=100 但是 Length(combobox.items.strings[0])>combobox.with 在下拉時 過長的內容就會被截掉 又因為combobox元件的width=下拉時list的width 不知道這個問題有沒有解 不好意思我沒表達好我的問題

Try the hint? e.g. http://www.vclxx.org/DELPHI/D32FREE/SKCMBHNT.ZIP

謝謝您 william！

參考:

procedure SetComboDropDownWidth(ComboBox: TComboBox; Width: Longint = -1); 
var 
  I, TextLen: Longint; 
begin 
  if Width < ComboBox.Width then 
  begin 
    ComboBox.Canvas.Handle := GetDC(ComboBox.Handle); 
    try 
      for I := 0 to ComboBox.Items.Count -1 do 
      begin 
        TextLen := ComboBox.Canvas.TextWidth(ComboBox.Items[I]); 
        if TextLen > Width then 
          Width := TextLen; 
      end;           (* Standard ComboBox drawing is Rect.Left   2, 
         adding the extra spacing offsets this *) 
      Inc(Width, 10); 
    finally 
      ReleaseDC(ComboBox.Handle, ComboBox.Canvas.Handle); 
    end; 
  end; 
  SendMessage(ComboBox.Handle, CB_SETDROPPEDWIDTH, Width, 0); 
end; 

-- 將進酒 杯莫停 與君歌一曲 請君為我傾耳聽

hagar先進： 謝謝！

===================引 用 hagar 文 章===================
參考:

 procedure SetComboDropDownWidth(ComboBox: TComboBox; Width: Longint = -1);  var    I, TextLen: Longint;  begin    if Width < ComboBox.Width then    begin      ComboBox.Canvas.Handle := GetDC(ComboBox.Handle);      try        for I := 0 to ComboBox.Items.Count -1 do        begin          TextLen := ComboBox.Canvas.TextWidth(ComboBox.Items[I]);          if TextLen > Width then            Width := TextLen;        end;         (* Standard ComboBox drawing is Rect.Left   2,           adding the extra spacing offsets this *)        Inc(Width, 10);      finally        ReleaseDC(ComboBox.Handle, ComboBox.Canvas.Handle);      end;    end;    SendMessage(ComboBox.Handle, CB_SETDROPPEDWIDTH, Width, 0);  end;  

-- 將進酒 杯莫停 與君歌一曲 請君為我傾耳聽


hagar版主的程式碼，我在使用時常會發生無效的形況，以下是我在網路上搜尋得的程式碼，目前使用上沒有問題，借花獻佛供大家參考。

delphi code

procedure SetComboDropDownWidth(ComboBox: TComboBox; Width: Integer = -1);
var
I, TextLen: Longint;
lf: LOGFONT;
f: HFONT;
begin
if Width < ComboBox.Width then begin
FillChar(lf,SizeOf(lf),0);
StrPCopy(lf.lfFaceName, ComboBox.Font.Name);
lf.lfHeight := ComboBox.Font.Height;
lf.lfWeight := FW_NORMAL;
if fsBold in ComboBox.Font.Style then
lf.lfWeight := lf.lfWeight or FW_BOLD;

f := CreateFontIndirect(lf);
if (f <> 0) then
begin
try
ComboBox.Canvas.Handle := GetDC(ComboBox.Handle);
SelectObject(ComboBox.Canvas.Handle,f);
try
for I := 0 to ComboBox.Items.Count -1 do begin
TextLen := ComboBox.Canvas.TextWidth(ComboBox.Items[I]);
if TextLen > Width then
Width := TextLen;
end;
(* Standard ComboBox drawing is Rect.Left 2,
adding the extra spacing offsets this *)
Inc(Width, GetSystemMetrics(SM_CYVTHUMB)
GetSystemMetrics(SM_CXVSCROLL));
finally
ReleaseDC(ComboBox.Handle, ComboBox.Canvas.Handle);
end;
finally
DeleteObject(f);
end;
end;
end;
SendMessage(ComboBox.Handle, CB_SETDROPPEDWIDTH, Width, 0);
end;

bcb code

void SetComboDropDownWidth(TComboBox *ComboBox,int Width)
{
int I,TextLen;
LOGFONT lf;
HFONT f;
if(Width < ComboBox->Width)
{
memset(&lf,0,sizeof(lf));
strcpy(lf.lfFaceName, ComboBox->Font->Name.c_str());
lf.lfHeight = ComboBox->Font->Height;
lf.lfWeight = FW_NORMAL;
if (ComboBox->Font->Style.Contains(fsBold))
lf.lfWeight = lf.lfWeight | FW_BOLD;

f = CreateFontIndirect(&lf);
if (f != NULL)
{
try
{
ComboBox->Canvas->Handle = GetDC(ComboBox->Handle);
SelectObject(ComboBox->Canvas->Handle,f);
try
{
for(I=0;IItems->Count;I )
{
TextLen = ComboBox->Canvas->TextWidth(ComboBox->Items->Strings[I]);
if(TextLen > Width)
Width = TextLen;
}
// Standard ComboBox drawing is Rect.Left 2,adding the extra spacing offsets this
Width = GetSystemMetrics(SM_CYVTHUMB) GetSystemMetrics(SM_CXVSCROLL);
}
__finally
{
ReleaseDC(ComboBox->Handle, ComboBox->Canvas->Handle);
}
}
__finally
{
DeleteObject(f);
}
}
}
SendMessage(ComboBox->Handle, CB_SETDROPPEDWIDTH, Width, 0);
}