為什麼沒有設定tcombobox的值, 也會出現數值 |
答題得分者是:william
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poemkevin
初階會員 發表:26 回覆:77 積分:30 註冊:2002-10-19 發送簡訊給我 |
這是在大陸網站上看到有人發問的問題, 都沒人解答.
蠻奇怪的問題,
視窗只有放一個Button1元件,
procedure TForm1.Button1Click(Sender: TObject);
var
xx:TComboBox;
begin
showmessage(xx.text);
//xx是TComboBox不是TButton,而且未初始化
end;
它顯示出來的值, 居然是Button1.Caption的值 procedure TForm1.Button1Click(Sender: TObject);
var
xx:TComboBox;
begin
showmessage(xx.Name);
//xx是TComboBox不是TEdit,而且未初始化
end;
它顯示出來的值, 居然是Form1.Name的值 覺得蠻奇怪的, 為什麼沒有設定tcombobox的值, 也會出現數值=.= ===========================
沉思, 再沉思! 學習, 再學習!
生活隨喜, 簡單自在^^
===========================
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william
版主 發表:66 回覆:2535 積分:3048 註冊:2002-07-11 發送簡訊給我 |
Optimization on? It is a bug... but I would rather blame the one who write this kind of code, not the compiler... warning should had been issued already... The compiler somehow decide that xx is not used in the whole procedure, so xx is removed from the local stack... Try below procedure with Optimization on. AV when the // test line is commented out (i.e. i will NOT be removed from the local stack due to optimization since it is in use now).
procedure TForm1.Button1Click(Sender: TObject); var i: integer; xx: TComboBox; begin showmessage(xx.Text); showmessage(IntToStr(i)); // test end; |
poemkevin
初階會員 發表:26 回覆:77 積分:30 註冊:2002-10-19 發送簡訊給我 |
引言: Optimization on? It is a bug... but I would rather blame the one who write this kind of code, not the compiler... warning should had been issued already... The compiler somehow decide that xx is not used in the whole procedure, so xx is removed from the local stack... Try below procedure with Optimization on. AV when the // test line is commented out (i.e. i will NOT be removed from the local stack due to optimization since it is in use now).謝謝大大的回應. 很感謝^^ 小弟以前曾寫程式時, 忘了給整數變數初始值, 就會亂跳一下數字出來 那時就覺得有點納悶,為什麼delphi 上會允許這些bug存在? =========================== 沉思, 再沉思! 學習, 再學習! 生活隨喜, 簡單自在^^ ===========================procedure TForm1.Button1Click(Sender: TObject); var i: integer; xx: TComboBox; begin showmessage(xx.Text); showmessage(IntToStr(i)); // test end; |
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