unit loginunit2;    interface    uses   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,   Dialogs, Buttons, StdCtrls, ExtCtrls, janColorButton, SpotLabel, Label3D,   ButtonWithColor;    type   TMainForm2 = class(TForm)     HmbPanel1: TPanel;     HmbEdit1: TEdit;     HmbPanel2: TPanel;     HmbjButton6: TjanColorButton;     HmbjButton5: TjanColorButton;     HmbjButton1: TjanColorButton;     HmbjButton2: TjanColorButton;     HmbjButton3: TjanColorButton;     HmbjButton4: TjanColorButton;     HmbSpotLabel1: TSpotLabel;     HmbLabel3D1: TLabel3D;     HmbLabel1: TLabel;     HmbBitBtn1: TBitBtnWithColor;     HmbBitBtn2: TBitBtnWithColor;     procedure HmaBitBtn2Click(Sender: TObject);     procedure FormActivate(Sender: TObject);     procedure HmbBitBtn2Click(Sender: TObject);     procedure HmbBitBtn1MouseMove(Sender: TObject; Shift: TShiftState; X,       Y: Integer);     procedure HmbBitBtn2MouseMove(Sender: TObject; Shift: TShiftState; X,       Y: Integer);     procedure HmbPanel1MouseMove(Sender: TObject; Shift: TShiftState; X,       Y: Integer);     procedure HmbEdit1KeyDown(Sender: TObject; var Key: Word;       Shift: TShiftState);     procedure HmbjButton1click(Sender: TObject);   private     { Private declarations }   public     { Public declarations }   end;    var   MainForm2: TMainForm2;    implementation uses loginunit1,frm2comp;    {$R *.dfm}    // 開啟另一個form procedure OpenForm(FormClass: TFormClass; var fm; AOwner:TComponent); // 54 line   var:fm var  i:integer;  Child:TForm; begin   for i := 0 to Screen.FormCount -1 do     if Screen.Forms[i].ClassType = FormClass then begin         Child:=Screen.Forms[i];         if Child.WindowState=wsMinimized then            ShowWindow(Child.handle,SW_SHOWNORMAL)         else            ShowWindow(Child.handle,SW_SHOWNA);         if (not Child.Visible) then Child.Visible:=True;         Child.BringToFront;         Child.Setfocus;          TForm(fm):=Child;  // 68 line         exit;     end;   Child:=TForm(FormClass.NewInstance);   TForm(fm):=Child;   //  72 line   Child.Create(AOwner); end;    錯誤訊息 [Warning] loginunit2.pas(54): Unsafe type 'procedure, untyped pointer or untyped parameter' [Warning] loginunit2.pas(68): Unsafe typecast of 'procedure, untyped pointer or untyped parameter' to 'TForm' [Warning] loginunit2.pas(72): Unsafe typecast of 'procedure, untyped pointer or untyped parameter' to 'TForm'    procedure TMainForm2.HmbjButton1click(Sender: TObject); begin ///////   OpenForm(TMainForm21,MainForm21,self);  ////////// end;    end. 發表人 - nick899 於 2003/03/26 23:44:53 發表人 - nick899 於 2003/03/26 23:46:20

是否應該這樣 : procedure OpenForm(FormClass: TFormClass; var fm : TForm; AOwner:TComponent);

引言: var fm:Tform 測式後, OpenForm(TFormComp1,FormComp1,self);呼叫Form出現另一個error message 1. [Error] loginunit2.pas(83): Types of actual and formal var parameters must be identical 2. [Fatal Error] HCmychk.dpr(8): Could not compile used unit 'loginunit2.pas'

那些 warning 有實則不良影響嗎? 若執行沒問題可不用理它們，因為你的程式事實上是有危險，fm 傳入甚麼也行，不一定是 TForm 的子代丫。    或，能否改成這樣(沒測試過) :

function OpenForm(FormClass: TFormClass; fm : TForm; AOwner:TComponent) : TForm;
var  i:integer;
 Child:TForm;
begin
  result := fm;
  for i := 0 to Screen.FormCount -1 do
    if Screen.Forms[i].ClassType = FormClass then begin
        Child:=Screen.Forms[i];
        if Child.WindowState=wsMinimized then
           ShowWindow(Child.handle,SW_SHOWNORMAL)
        else
           ShowWindow(Child.handle,SW_SHOWNA);
        if (not Child.Visible) then Child.Visible:=True;
        Child.BringToFront;
        Child.Setfocus; 
        exit;
    end;
  result:=TForm(FormClass.NewInstance);
  result.Create(AOwner);
end;

補充呼叫時的改變

procedure TMainForm2.HmbjButton1click(Sender: TObject);
begin
///////
  MainForm21 := OpenForm(TMainForm21,MainForm21,self); 
//////////
end;

引言: function OpenForm(FormClass: TFormClass; fm : TForm; AOwner:TComponent) : TForm; var i:integer; Child:TForm; begin result := fm; for i := 0 to Screen.FormCount -1 do if Screen.Forms[i].ClassType = FormClass then begin Child:=Screen.Forms[i]; if Child.WindowState=wsMinimized then ShowWindow(Child.handle,SW_SHOWNORMAL) else ShowWindow(Child.handle,SW_SHOWNA); if (not Child.Visible) then begin Child.Visible:=True; Child.BringToFront; Child.Setfocus; exit; end; // 是否要加begin ...end;,有或沒有是否有影響? end; result:=TForm(FormClass.NewInstance); result.Create(AOwner); end; [/code] mainform2 呼叫 FormComp1 FormComp1 := OpenForm(TFormComp1,FormComp1,self); error message: 1.[Error] loginunit2.pas(86): Incompatible types: 'TFormComp1' and 'TForm' 2. [Fatal Error] HCmychk.dpr(8): Could not compile used unit 'loginunit2.pas'

FormComp1 := TFormComp1(OpenForm(TFormComp1,FormComp1,self)); 這樣就不會有 Compile Error ，不過你要試試能否逹到你要的效果。

引言: 可以了,達到我所需要的,謝謝Justmade 但請原諒我又有一個小問題? mianform2.hide; // 先把 hide FormComp1 := TFormComp1(OpenForm(TFormComp1,FormComp1,self)); 當執行FormComp1之後在 onclose 加mainform2.show 每 *.exe 都有很都form,form1,form2,.....如何簡化form1.hide,在form2.onclose -> form1.show ......重覆寫程式... 可否請教Justmade 可有簡化方法,或它這麼做是必然的

新問題請儘量開新題目。    在 TMainForm2 的 Public 加入 : procedure ChildFormClose(Sender: TObject; var Action: TCloseAction);    implementation : procedure TMainForm2.ChildFormClose(Sender: TObject; var Action: TCloseAction); begin   Show; close;    在 OpenForm 的最後加上 : result.OnClose := MainForm2.ChildFormClose;    若有些 Form 不是經由 OpenForm Create 的，那在 OpenForm 的 exit; 一包前也要加上 child.OnClose := MainForm2.ChildFormClose; 這樣就不用每個 Form 寫了 修正紅色部份。 發表人 - Justmade 於 2003/03/27 14:37:31