function MessageDlg(const Msg: string; DlgType: TMsgDlgType;
Buttons: TMsgDlgButtons; HelpCtx: Longint): Integer;
begin
Result := MessageDlgPosHelp(Msg, DlgType, Buttons, HelpCtx, -1, -1, '');
end;
function MessageDlgPos(const Msg: string; DlgType: TMsgDlgType;
Buttons: TMsgDlgButtons; HelpCtx: Longint; X, Y: Integer): Integer;
begin
Result := MessageDlgPosHelp(Msg, DlgType, Buttons, HelpCtx, X, Y, '');
end;
function MessageDlgPosHelp(const Msg: string; DlgType: TMsgDlgType;
Buttons: TMsgDlgButtons; HelpCtx: Longint; X, Y: Integer;
const HelpFileName: string): Integer;
begin
with CreateMessageDialog(Msg, DlgType, Buttons) do
try
HelpContext := HelpCtx;
HelpFile := HelpFileName;
if X >= 0 then Left := X;
if Y >= 0 then Top := Y;
if (Y < 0) and (X < 0) then Position := poScreenCenter;
Result := ShowModal;
finally
Free;
end;
end;
function CreateMessageDialog(const Msg: string; DlgType: TMsgDlgType;
Buttons: TMsgDlgButtons): TForm;
const
mcHorzMargin = 8;
mcVertMargin = 8;
mcHorzSpacing = 10;
mcVertSpacing = 10;
mcButtonWidth = 50;
mcButtonHeight = 14;
mcButtonSpacing = 4;
var
DialogUnits: TPoint;
HorzMargin, VertMargin, HorzSpacing, VertSpacing, ButtonWidth,
ButtonHeight, ButtonSpacing, ButtonCount, ButtonGroupWidth,
IconTextWidth, IconTextHeight, X, ALeft: Integer;
B, DefaultButton, CancelButton: TMsgDlgBtn;
IconID: PChar;
TextRect: TRect;
begin
Result := TMessageForm.CreateNew(Application);
with Result do
begin
BiDiMode := Application.BiDiMode;
BorderStyle := bsDialog;
Canvas.Font := Font;
DialogUnits := GetAveCharSize(Canvas);
HorzMargin := MulDiv(mcHorzMargin, DialogUnits.X, 4);
VertMargin := MulDiv(mcVertMargin, DialogUnits.Y, 8);
HorzSpacing := MulDiv(mcHorzSpacing, DialogUnits.X, 4);
VertSpacing := MulDiv(mcVertSpacing, DialogUnits.Y, 8);
ButtonWidth := MulDiv(mcButtonWidth, DialogUnits.X, 4);
for B := Low(TMsgDlgBtn) to High(TMsgDlgBtn) do
begin
if B in Buttons then
begin
if ButtonWidths = 0 then
begin
TextRect := Rect(0,0,0,0);
Windows.DrawText( canvas.handle,
PChar(LoadResString(ButtonCaptions)), -1,
TextRect, DT_CALCRECT or DT_LEFT or DT_SINGLELINE or
DrawTextBiDiModeFlagsReadingOnly);
with TextRect do ButtonWidths := Right - Left + 8;
end;
if ButtonWidths > ButtonWidth then
ButtonWidth := ButtonWidths;
end;
end;
ButtonHeight := MulDiv(mcButtonHeight, DialogUnits.Y, 8);
ButtonSpacing := MulDiv(mcButtonSpacing, DialogUnits.X, 4);
SetRect(TextRect, 0, 0, Screen.Width div 2, 0);
DrawText(Canvas.Handle, PChar(Msg), Length(Msg)+1, TextRect,
DT_EXPANDTABS or DT_CALCRECT or DT_WORDBREAK or
DrawTextBiDiModeFlagsReadingOnly);
IconID := IconIDs[DlgType];
IconTextWidth := TextRect.Right;
IconTextHeight := TextRect.Bottom;
if IconID <> nil then
begin
Inc(IconTextWidth, 32 + HorzSpacing);
if IconTextHeight < 32 then IconTextHeight := 32;
end;
ButtonCount := 0;
for B := Low(TMsgDlgBtn) to High(TMsgDlgBtn) do
if B in Buttons then Inc(ButtonCount);
ButtonGroupWidth := 0;
if ButtonCount <> 0 then
ButtonGroupWidth := ButtonWidth * ButtonCount +
ButtonSpacing * (ButtonCount - 1);
ClientWidth := Max(IconTextWidth, ButtonGroupWidth) + HorzMargin * 2;
ClientHeight := IconTextHeight + ButtonHeight + VertSpacing +
VertMargin * 2;
Left := (Screen.Width div 2) - (Width div 2);
Top := (Screen.Height div 2) - (Height div 2);
if DlgType <> mtCustom then
Caption := LoadResString(Captions[DlgType]) else
Caption := Application.Title;
if IconID <> nil then
with TImage.Create(Result) do
begin
Name := 'Image';
Parent := Result;
Picture.Icon.Handle := LoadIcon(0, IconID);
SetBounds(HorzMargin, VertMargin, 32, 32);
end;
with TLabel.Create(Result) do
begin
Name := 'Message';
Parent := Result;
WordWrap := True;
Caption := Msg;
BoundsRect := TextRect;
BiDiMode := Result.BiDiMode;
ALeft := IconTextWidth - TextRect.Right + HorzMargin;
if UseRightToLeftAlignment then
ALeft := Result.ClientWidth - ALeft - Width;
SetBounds(ALeft, VertMargin,
TextRect.Right, TextRect.Bottom);
end;
if mbOk in Buttons then DefaultButton := mbOk else
if mbYes in Buttons then DefaultButton := mbYes else
DefaultButton := mbRetry;
if mbCancel in Buttons then CancelButton := mbCancel else
if mbNo in Buttons then CancelButton := mbNo else
CancelButton := mbOk;
X := (ClientWidth - ButtonGroupWidth) div 2;
for B := Low(TMsgDlgBtn) to High(TMsgDlgBtn) do
if B in Buttons then
with TButton.Create(Result) do
begin
Name := ButtonNames;
Parent := Result;
Caption := LoadResString(ButtonCaptions);
ModalResult := ModalResults;
if B = DefaultButton then Default := True;
if B = CancelButton then Cancel := True;
SetBounds(X, IconTextHeight + VertMargin + VertSpacing,
ButtonWidth, ButtonHeight);
Inc(X, ButtonWidth + ButtonSpacing);
if B = mbHelp then
OnClick := TMessageForm(Result).HelpButtonClick;
end;
end;
end;
自己到dialogs 中去看一下吧。
