之前問過版上大大
得到答案

[code delphi]
var
a : TObject;
begin
if Assigned(FCallBack) then
a := Listview1.Selected;
FCallBack(a);
end;
[/code]


[code delphi]
var
a: TDBImage;
begin
if Sender is TListItem then
Label1.Caption := TListItem(Sender).Caption;
a := TDBImage(Sender);
Label1.Caption := a.Name;
end;
[/code]

回傳的sender格式被定在TListItem
我希望回傳的是object
請問怎麼改

嗯，這…我想…您要好好的再看一下原本我寫的程式了，那個Sender 傳進來的的確是 TObject 呀，
所以你要 TDBImage 當然也可以用
當然就再多加一下如下面綠色註解的地方就可以了，請自己嘗試著舉一反三看看.....

===================引 用 sunhihi 文 章===================
之前問過版上大大
得到答案

[code delphi]
var
a : TObject;
begin
if Assigned(FCallBack) and (Listview1.Selected <> nil) then
a := Listview1.Selected; // 這邊為什麼要再 Assign 一次變數? 直接 FCallBack(Listview1.Selected) 就行了
FCallBack(a); // 而且這個 FCallBack 不在 if 的判斷式內，如果沒有 assign 時，您的程式就會出錯!!
end;
[/code]


[code delphi]
var
a: TDBImage;
begin
if Sender is TListItem then
Label1.Caption := TListItem(Sender).Caption;
if Sender is TDBImage then // 加這個就行了
Label1.Caption := TDBImage(Sender).Name;
end;
[/code]

回傳的sender格式被定在TListItem
我希望回傳的是object
請問怎麼改

------
價值的展現，來自於你用哪一個角度來看待它!!

===================引 用 careychen 文 章===================
嗯，這…我想…您要好好的再看一下原本我寫的程式了，那個Sender 傳進來的的確是 TObject 呀，
所以你要 TDBImage 當然也可以用
當然就再多加一下如下面綠色註解的地方就可以了，請自己嘗試著舉一反三看看.....


[code delphi]
var
a : TObject;
begin
if Assigned(FCallBack) and (Listview1.Selected <> nil) then begin
a := Listview1.Selected;
FCallBack(a);
end;
end;
[/code]


[code delphi]
var
a: TDBImage;
begin
if Sender is TListItem then
Label1.Caption := TListItem(Sender).Caption;
if Sender is TDBImage then // 加這個就行了
Label1.Caption := TDBImage(Sender).Name;
Label1.Caption := Sender.ClassName; //出現的答案是TListItem
//我希望他出現的答案是object
end;
[/code]

那我們這樣似乎問與答有點不大對，重新請教您，出現 Object 的目的與您想要達成的目標是什麼?

===================引 用 sunhihi 文 章===================

===================引 用 careychen 文 章===================
嗯，這…我想…您要好好的再看一下原本我寫的程式了，那個Sender 傳進來的的確是 TObject 呀，
所以你要 TDBImage 當然也可以用
當然就再多加一下如下面綠色註解的地方就可以了，請自己嘗試著舉一反三看看.....


[code delphi]
var
a : TObject;
begin
if Assigned(FCallBack) and (Listview1.Selected <> nil) then begin
a := Listview1.Selected;
FCallBack(a);
end;
end;
[/code]


[code delphi]
var
a: TDBImage;
begin
if Sender is TListItem then
Label1.Caption := TListItem(Sender).Caption;
if Sender is TDBImage then // 加這個就行了
Label1.Caption := TDBImage(Sender).Name;
Label1.Caption := Sender.ClassName; //出現的答案是TListItem
//我希望他出現的答案是object
end;
[/code]

------
價值的展現，來自於你用哪一個角度來看待它!!

聽說TListItem Data 可以達到差不多的效果
不過我不太會
還是請教一下了

===================引 用 careychen 文 章===================
那我們這樣似乎問與答有點不大對，重新請教您，出現 Object 的目的與您想要達成的目標是什麼?

[code delphi]
var
a : TObject;
begin
if Assigned(FCallBack) and (Listview1.Selected <> nil) then begin
a := Listview1.Selected;
FCallBack(a);
end;
//我點選Listview1上的內容並將訊息callback回傳
end;
[/code]


[code delphi]
var
a: TDBImage;//宣告一a作為可變動TDBImage
begin
if Sender is TListItem then
Label1.Caption := TListItem(Sender).Caption;
a := TDBImage(Sender);//如果sender.classname是TDBImage則它可作為可變動TDBImage
a.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TListItem(Sender).Caption '' '.jpg');



Label1.Caption := Sender.ClassName; //出現的答案是TListItem
//因而我希望他出現的答案是TObject甚至可以應用到其他的物件
end;
[/code]

編輯記錄

其實您這樣的問題，還是沒有問到重點，那個 TListItem data 的【效果】是什麼?
跟 Object 有什麼關係嗎? 還是您預期想要的是什麼結果?

看您的問題問的還有點深度，但卻不知道 TObject ，您是從別的語言轉過來的嗎?

===================引 用 sunhihi 文 章===================
聽說TListItem Data 可以達到差不多的效果
不過我不太會
還是請教一下了

------
價值的展現，來自於你用哪一個角度來看待它!!

===================引 用 careychen 文 章===================
其實您這樣的問題，還是沒有問到重點，那個 TListItem data 的【效果】是什麼?
跟 Object 有什麼關係嗎? 還是您預期想要的是什麼結果?

看您的問題問的還有點深度，但卻不知道 TObject ，您是從別的語言轉過來的嗎?

TListItem data 的原文定義
Use Data to associate arbitrary data structure with the list item. When the user selects or deletes the list item, Data allows the application to quickly access information about the meaning of the list item to implement the appropriate response.
牽涉到TListItem內容的增減
跟我之前問的問題沒啥關係~我搞錯方向(這部分我還沒寫到啦)

TObject就是物件的源頭嘛
只要能將回傳的訊息以TObject表示
我可以將其轉成任何物件的代數
由於TObject可以往下繼承
TListItem卻沒辦法往上回朔
因而 TListItem-->TDBimage不可能
TListItem -->TObject就更不可能
現在寫的和之前問你的程式有若干變動再貼一程式碼好了


[code delphi]
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, DBCtrls, Db, DBTables, ImgList, ExtCtrls, CnsJpgGr, Comctrls;
type
TForm1 = class(TForm)
DBImage1: TDBImage;
DBImage2: TDBImage;
DBImage3: TDBImage;
DBImage4: TDBImage;
DBImage5: TDBImage;
DBImage6: TDBImage;
DBImage7: TDBImage;
DBImage8: TDBImage;
DBImage9: TDBImage;
Button1: TButton;
Button2: TButton;
Label1: TLabel;
DBImage10: TDBImage;
DBImage11: TDBImage;
DBImage12: TDBImage;
DBImage13: TDBImage;
DBImage14: TDBImage;
DBImage15: TDBImage;
DBImage16: TDBImage;
DBImage17: TDBImage;
DBImage18: TDBImage;
DBImage19: TDBImage;
DBImage20: TDBImage;
Image1: TImage;
Database1: TDatabase;
Query1: TQuery;
DataSource1: TDataSource;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure DBImage1Click(Sender: TObject);
procedure DBImage2Click(Sender: TObject);
procedure DBImage3Click(Sender: TObject);
procedure DBImage4Click(Sender: TObject);
procedure DBImage5Click(Sender: TObject);
procedure DBImage6Click(Sender: TObject);
procedure DBImage7Click(Sender: TObject);
procedure DBImage8Click(Sender: TObject);
procedure DBImage9Click(Sender: TObject);
procedure DBImage10Click(Sender: TObject);
procedure DBImage11Click(Sender: TObject);
procedure DBImage12Click(Sender: TObject);
procedure DBImage13Click(Sender: TObject);
procedure DBImage14Click(Sender: TObject);
procedure DBImage15Click(Sender: TObject);
procedure DBImage16Click(Sender: TObject);
procedure DBImage17Click(Sender: TObject);
procedure DBImage18Click(Sender: TObject);
procedure DBImage19Click(Sender: TObject);
procedure DBImage20Click(Sender: TObject);
private
procedure CallBack(Sender: TObject);
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
uses Unit2;
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
list: TList;
begin
list := TList.Create;
list.Add(DBImage1);
list.Add(DBImage2);
list.Add(DBImage3);
list.Add(DBImage4);
list.Add(DBImage5);
list.Add(DBImage6);
list.Add(DBImage7);
list.Add(DBImage8);
list.Add(DBImage9);
list.Add(DBImage10);
list.Add(DBImage11);
list.Add(DBImage12);
list.Add(DBImage13);
list.Add(DBImage14);
list.Add(DBImage15);
list.Add(DBImage16);
list.Add(DBImage17);
list.Add(DBImage18);
list.Add(DBImage19);
//list.Add(DBImage20);
ShowForm(list, CallBack);
end;
procedure TForm1.CallBack(Sender: TObject);
var
a: TDBImage;
begin
if Sender is TListItem then
//Label1.Caption := TListItem(Sender).Caption;
Label1.Caption := TWinControl(Sender).Name;
if Sender is TDBImage then
Label1.Caption := TDBImage(Sender).Name;
//a := TDBImage(Sender);
//Label1.Caption := a.name;
// a.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TListItem(Sender).Caption '' '.jpg');
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TListItem(Sender).Caption '' '.jpg');
//-----------------------------------
{try
Label1.Caption := TWinControl(Sender).Name;
a := TDBImage(Sender);
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
a.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end
else
begin
Label1.Caption :='無圖片';
Image1.Picture := nil;
end;
except
Label1.Caption :='無空位';
end;
}
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
FreeForm;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
//Label1.Caption := Image1.Picture
end;
procedure TForm1.DBImage1Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage2Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage3Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage4Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage5Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage6Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage7Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage8Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage9Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage10Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage11Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage12Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage13Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage14Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage15Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage16Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage17Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage18Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage19Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
procedure TForm1.DBImage20Click(Sender: TObject);
begin
if FileExists('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg') then
begin
Image1.Picture.LoadFromFile('C:\Documents and Settings\Administrator\My Documents\Picture\' '' TWinControl(Sender).Name '' '.jpg');
end;
end;
end.
[/code]

[code delphi]
unit Unit2;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, Db, DBTables, Grids, DBGrids, ComCtrls;
type
TForm2 = class(TForm)
GroupBox1: TGroupBox;
Button1: TButton;
Button2: TButton;
Button3: TButton;
Button4: TButton;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
Label5: TLabel;
ComboBox1: TComboBox;
ComboBox2: TComboBox;
Memo1: TMemo;
Edit1: TEdit;
Edit2: TEdit;
ListView1: TListView;
procedure ListView1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure Button4Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
FCallBack: TNotifyEvent;
FList: TList;
procedure SetDisplayList(list: TList);
procedure FreeDisplayList;
public
end;
procedure ShowForm(list: TList; CallBack: TNotifyEvent);
procedure FreeForm;
implementation
var
Form2: TForm2;
{$R *.DFM}
procedure TForm2.ListView1Click(Sender: TObject);
var
a : TObject;
begin
if Assigned(FCallBack) and (Listview1.Selected <> nil) then begin
a := Listview1.Selected;
FCallBack(a);
end;
end;
procedure TForm2.SetDisplayList(list: TList);
var
idx: Integer;
begin
FList := list;
ListView1.items.Clear;
if (Assigned(list) and (list.Count > 0)) then
for idx := 0 to list.Count - 1 do
ListView1.Items.Add.Caption := TWinControl(list.Items[idx]).Name;
Edit2.Text := DateTimeToStr(Now);
end;
procedure TForm2.FreeDisplayList;
begin
FreeAndNil(FList);
end;
procedure ShowForm(list: TList; CallBack: TNotifyEvent);
begin
if (not Assigned(Form2)) then
Form2 := TForm2.Create(Application);
Form2.FCallBack := CallBack;
Form2.SetDisplayList(list);
Form2.Show;
end;
procedure FreeForm;
begin
if (Assigned(Form2)) then
FreeAndNil(Form2);
end;
procedure TForm2.FormCreate(Sender: TObject);
begin
Edit2.Text:=DateTimeToStr(Now);
end;
procedure TForm2.Button4Click(Sender: TObject);
begin
close;
end;
procedure TForm2.Button2Click(Sender: TObject);
begin
ListView1.Items.Add.Caption := Edit1.Text;
//Flist.Add(Edit1.Text);
FCallBack(Flist);
end;
end.

[/code]

編輯記錄

這…看這麼多程式碼頭會暈，先跟您說幾個問題，您先看看吧

第一：DBImage1~20 的程式碼都一樣，改成一個就好了
第二：在 Unit1 裡的 Callback Function 裡，有寫 if Sender is TDBImage .... 這段，但我沒看到在 Unit2 裡有用到 TDBImage ，所以這個是用來.....?? 做什麼動作的?
第三：
由於TObject可以往下繼承
TListItem卻沒辦法往上回朔 // 為什麼沒辦法? 那傳進來的 Sender 不就是 TObject 了嗎?
因而 TListItem-->TDBimage不可能 // 當然不可能，這已經是不同分支的之後再向下繼承的

-> 爺爺1 -> 爸爸1 -> 兒子1 (TDBImage)
曾祖先 (TObject)-> 祖先
-> 爺爺2 -> 爸爸2 -> 兒子2 (TListItem)

TListItem -->TObject就更不可能 // 還是回到剛那一句，傳進來的已經就是 TObject 了!!

物件的觀念，建議您還是先了解清楚一點，用事件傳遞的過程您比較不會混亂!!

------
價值的展現，來自於你用哪一個角度來看待它!!

===================引 用 careychen 文 章===================
我在研究好了
雖然沒有達到我預想中的效果
不過還是感謝你了

順便一提
我是菜鳥嘛
沒概念= 3 =

編輯記錄