我已经编写了一个TOpenPictDialog(源代码见下文)组件,在调用时最终在某些情况下失败
结果:= TDialogFunc(DialogFunc)(DialogData);
在Dialogs.pas中的。由于DialogFunc正确指向GetOpenFileName,我之后调用CommDlgExtendedError进行测试以找出错误。它返回CDERR_FINDRESFAILURE。在这种情况下,对话框根本不显示。我的测试表只包含一个按钮和TOpenPictDialog组件,当按下按钮时,OpenPictDialog1-> Execute被调用 - 这就是全部。
非常奇怪的是, 在以下其中一个情况下完美地工作(除了调整大小时TListView闪烁):
a)在&#34中添加ExtDlgs;使用"在呼唤形式 b)在不调用它的情况下将原始的TOpenPictureDialog添加到表单中 c)将包含TOpenPictDialog的PAS文件添加到项目中(虽然已经安装了TOpenPictDialog)
如果我用一个调用表单编写C ++ Builder应用程序,我永远不会让TOpenPictDialog工作(即使我添加了额外的TOpenPictureDialog组件)。
unit PictureDlg;
{$R-,H+,X+}
{$IF CompilerVersion > 23} {$DEFINE GE_DXE2} {$IFEND}
interface
{$IFDEF GE_DXE2}
uses Winapi.Messages, Winapi.Windows, System.SysUtils, System.Classes, Vcl.Controls, Vcl.StdCtrls,
Vcl.Graphics, Vcl.ExtCtrls, Vcl.Buttons, Vcl.Dialogs, Vcl.ExtDlgs, Vcl.Consts, Vcl.ComCtrls;
{$ELSE}
uses Messages, Windows, SysUtils, Classes, Controls, StdCtrls,
Graphics, ExtCtrls, Buttons, Dialogs, ExtDlgs, Consts, ComCtrls;
{$ENDIF}
(*$HPPEMIT '// Alias records for C++ code that cannot compile in STRICT mode yet.' *)
(*$HPPEMIT '#if defined(_VCL_ALIAS_RECORDS)' *)
(*$HPPEMIT '#if !defined(STRICT)' *)
// (*$HPPEMIT ' #pragma alias "@Vcl@Extdlgs@TOpenPictDialog@Execute$qqrpv"="@Vcl@Extdlgs@TOpenPictDialog@Execute$qqrp6HWND__"' *)
(*$HPPEMIT '#endif' *)
(*$HPPEMIT '#endif' *)
type
{ TOpenPictDialog }
TOpenPictDialog = class(TOpenDialog)
private
FListView: TListView;
FTopLabel, FBottomLabel: TStaticText;
FImageCtrl: TImage;
FSavedFilename: string;
FOldDialogWndProc: Pointer;
FDialogMethodInstance: Pointer;
FDialogHandle: THandle;
function IsFilterStored: Boolean;
procedure DialogWndProc(var Msg: TMessage);
protected
procedure DoClose; override;
procedure DoSelectionChange; override;
procedure DoShow; override;
function TaskModalDialog(DialogFunc: Pointer; var DialogData): Bool; override;
published
property Filter stored IsFilterStored;
public
constructor Create(AOwner: TComponent); override;
function Execute(ParentWnd: HWND): Boolean; override;
property DialogListView: TListView read FListView;
property DialogImage: TImage read FImageCtrl;
property TopLabel: TStaticText read FTopLabel;
property BottomLabel: TStaticText read FBottomLabel;
end;
procedure Register;
implementation
uses
{$IFDEF GE_DXE2}
{$IF DEFINED(CLR)}
System.Runtime.InteropServices, System.Reflection, System.Security.Permissions, System.IO,
{$IFEND}
System.Math, Vcl.Forms, Winapi.CommDlg, Winapi.Dlgs, System.Types, Winapi.ShlObj, Winapi.ActiveX;
{$ELSE}
{$IF DEFINED(CLR)}
InteropServices, Reflection, Permissions, IO,
{$IFEND}
Math, Forms, CommDlg, Dlgs, Types, ShlObj, ActiveX;
{$ENDIF}
{ TOpenPictDialog }
constructor TOpenPictDialog.Create(AOwner: TComponent);
begin
FDialogHandle := 0;
FDialogMethodInstance := NIL;
inherited Create(AOwner);
Filter := GraphicFilter(TGraphic);
FListView := TListView.Create(Self);
FImageCtrl := TImage.Create(Self);
with FListView do
begin
Name := 'ListView';
SetBounds(204, 5, 169, 200);
BevelOuter := bvNone;
BorderWidth := 6;
TabOrder := 1;
Color := clWindow;
ParentDoubleBuffered := false;
DoubleBuffered := true;
OwnerDraw := true;
Ctl3D := true;
with FImageCtrl do
begin
Picture := nil;
Name := 'Image';
Parent := FListView;
end;
end;
FTopLabel := TStaticText.Create(Self);
with FTopLabel do
begin
Name := 'TopLabel';
SetBounds(6, 6, 157, 23);
AutoSize := False;
Caption := 'Preview:';
end;
FBottomLabel := TStaticText.Create(Self);
with FBottomLabel do
begin
Name := 'BottomLabel';
SetBounds(6, 6, 157, 23);
AutoSize := False;
Caption := 'Image size: 208 x 149 px';
Alignment := taCenter;
end;
end;
procedure TOpenPictDialog.DialogWndProc(var Msg: TMessage);
var
PreviewRect, ListViewRect, WindowRect, LabelRect: TRect;
WndControl: HWND;
begin
Msg.Result := CallWindowProc(FOldDialogWndProc, FDialogHandle, Msg.Msg, Msg.WParam, Msg.LParam);
if ((Msg.Msg = WM_WINDOWPOSCHANGED) and
((TWMWindowPosMsg(Msg).WindowPos.Flags and SWP_NOSIZE) = 0)) or
(Msg.Msg = WM_SHOWWINDOW) then begin
PreviewRect := FListView.BoundsRect;
GetWindowRect(Handle, WindowRect);
WndControl := FindWindowEx(FDialogHandle, 0, 'SHELLDLL_DefView', nil);
WndControl := FindWindowEx(WndControl, 0, 'SysListView32', nil);
if WndControl <> 0 then begin
GetWindowRect(WndControl, ListViewRect);
PreviewRect.Top := ListViewRect.Top - WindowRect.Top;
PreviewRect.Bottom := PreviewRect.Top + ListViewRect.Bottom - ListViewRect.Top;
if (not EqualRect(PreviewRect, FListView.BoundsRect)) then
FListView.BoundsRect := PreviewRect;
LabelRect := PreviewRect;
Dec(LabelRect.Top, 24);
LabelRect.Bottom := LabelRect.Top + 16;
FTopLabel.BoundsRect := LabelRect;
LabelRect := PreviewRect;
LabelRect.Top := PreviewRect.Bottom + 9;
LabelRect.Bottom := LabelRect.Top + 16;
FBottomLabel.BoundsRect := LabelRect;
end;
end;
end;
procedure TOpenPictDialog.DoSelectionChange;
var
FullName: string;
function ValidFile(const FileName: string): Boolean;
begin
Result := FileGetAttr(FileName) <> -1;
end;
begin
FullName := FileName;
if FullName <> FSavedFilename then
begin
FSavedFilename := FullName;
end;
inherited DoSelectionChange;
end;
procedure TOpenPictDialog.DoClose;
begin
if Assigned(FDialogMethodInstance) then begin
SetWindowLong(FDialogHandle, GWL_WNDPROC, Integer(FOldDialogWndProc));
FreeObjectInstance(FDialogMethodInstance);
end;
FDialogHandle := 0;
FDialogMethodInstance := NIL;
inherited DoClose;
{ Hide any hint windows left behind }
Application.HideHint;
end;
procedure TOpenPictDialog.DoShow;
var
PreviewRect, StaticRect, OldDialogRect: TRect;
DialogWidth, DialogHeight, NewLeft, NewTop: integer;
const
SizeIncrease = 25;
begin
FDialogHandle := GetParent(Handle);
GetWindowRect(FDialogHandle, OldDialogRect);
DialogWidth := OldDialogRect.Right - OldDialogRect.Left + SizeIncrease;
DialogHeight := OldDialogRect.Bottom - OldDialogRect.Top;
NewLeft := (Screen.Width - DialogWidth) div 2;
NewTop := (Screen.Height - DialogHeight) div 2;
GetWindowRect(Handle, PreviewRect);
MoveWindow(FDialogHandle, NewLeft, NewTop, DialogWidth, DialogHeight, true);
MoveWindow(Handle, 0, 0, PreviewRect.Right - PreviewRect.Left + SizeIncrease, PreviewRect.Bottom - PreviewRect.Top, false);
StaticRect := GetStaticRect;
GetClientRect(Handle, PreviewRect);
PreviewRect.Left := StaticRect.Left + (StaticRect.Right - StaticRect.Left);
Inc(PreviewRect.Top, 4);
Dec(PreviewRect.Right, 8);
Dec(PreviewRect.Bottom, 20);
FListView.BoundsRect := PreviewRect;
FDialogMethodInstance := MakeObjectInstance(DialogWndProc);
FOldDialogWndProc := Pointer(SetWindowLong(FDialogHandle, GWL_WNDPROC, Integer(FDialogMethodInstance)));
FSavedFilename := '';
FListView.ParentWindow := Handle;
FTopLabel.ParentWindow := Handle;
FBottomLabel.ParentWindow := Handle;
inherited DoShow;
end;
[UIPermission(SecurityAction.LinkDemand, Window=UIPermissionWindow.SafeSubWindows)]
function TOpenPictDialog.Execute(ParentWnd: HWND): Boolean;
begin
if NewStyleControls and not (ofOldStyleDialog in Options) and not
((Win32MajorVersion >= 6) and UseLatestCommonDialogs) then
Template := 'DLGTEMPLATE'
else
{$IF DEFINED(CLR)}
Template := '';
{$ELSE}
Template := nil;
{$IFEND}
Result := inherited Execute(ParentWnd);
end;
function TOpenPictDialog.TaskModalDialog(DialogFunc: Pointer; var DialogData): Bool;
begin
// This makes sense ONLY if you are compiling with a run-time packages
// Thanks to Peter Below (www.delphifaq.com)
TOpenfilename(Dialogdata).hInstance := FindClassHInstance(Classtype);
Result := inherited TaskModalDialog(DialogFunc, DialogData);
end;
function TOpenPictDialog.IsFilterStored: Boolean;
begin
Result := not (Filter = GraphicFilter(TGraphic));
end;
procedure Register;
begin
RegisterComponents('Dialogs', [TOpenPictDialog]);
end;
end.
答案 0 :(得分:1)
当你从 ExtDlgs.pas 复制代码开始编写你的代码时,你没有足够的复制。特别是,您没有复制链接关联的 ExtDlgs.rc 文件的$R
指令,该文件包含描述自定义对话框的附加布局的对话框资源。
您的代码告诉API使用名为DLGTEMPLATE的对话框资源,但您尚未在程序中包含该资源。这就解释了为什么你得到的错误代码是找不到资源。使用ExtDlgs单元具有链接该单元的相关资源的副作用。
将对话框模板从 ExtDlgs.rc 复制到您自己的RC文件中,并将其链接为 ExtDlgs.pas 。但是,请为资源使用其他名称,以避免与现有DLGTEMPLATE资源发生名称冲突。相应地调整您的代码。