请问HeyTommy,这段源码为什么去了Button会出错? (50分)

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs,registry, StdCtrls;

type
TForm1 = class(TForm)

Label1: TLabel;

private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

var
TempReg:TRegistry;
TempValue:string;
begin
TempReg:=TRegistry.Create;
try
TempReg.RootKey:=HKEY_LOCAL_MACHINE;
if TempReg.OpenKey('/Software/Microsoft/Windows/CurrentVersion/',false) then
begin
if tempreg.ValueExists('ProductId') then
begin
TempValue:=TempReg.ReadString('ProductId');
label1(出错).caption:=tempvalue;
end
else
ShowMessage('ProductID is not exist!');
end;
finally
TempReg.CloseKey;
TempReg.Free;
end;
end;

end.

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls,Registry;

type
TForm1 = class(TForm)
CheckBox1: TCheckBox;
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}
var
TempReg:TRegistry;
TempValue:string;
begin
TempReg:=TRegistry.Create;
try
TempReg.RootKey:=HKEY_LOCAL_MACHINE;
if TempReg.OpenKey('/Software/Microsoft/Windows/CurrentVersion/',false) then
begin
if tempreg.ValueExists('ProductId') then
begin
TempValue:=TempReg.ReadString('ProductId');
checkbox1.checked:=true;
end
else
ShowMessage('ProductID is not exist!');
end;
finally
TempReg.CloseKey;
TempReg.Free;
end;
end;

end.
这个呢?一样地方出错!

我想叫他在不加时钟的情况下,一打开程序便显示?

当然出错了，你在单元初始化的时候引用TForm1的的实例，可是这时候TForm1的实例
还没有创建呢。

再详细点,我想叫他在不加时钟的情况下,一打开程序便显示?帮改码,给你加分!

如果你想在Form1上显示，那么只要把这些代码放到Form1的OnCreate事件里就可以了

改一下源码吧!谢!

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Label1: TLabel;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation
uses
Registry;
{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
TempReg:TRegistry;
TempValue:string;
begin
TempReg:=TRegistry.Create;
try
TempReg.RootKey:=HKEY_LOCAL_MACHINE;
if TempReg.OpenKey('/Software/Microsoft/Windows/CurrentVersion/',false) then
begin
if tempreg.ValueExists('ProductId') then
begin
TempValue:=TempReg.ReadString('ProductId');
label1.caption:=tempvalue;
end
else
ShowMessage('ProductID is not exist!');
end;
finally
TempReg.CloseKey;
TempReg.Free;
end;
end;

end.

-------------------------------------------------------------------------------
下面代码程序,label显示序列号
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs,Registry, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
Label1: TLabel;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
TempReg:TRegistry;
TempValue:string;
begin
TempReg:=TRegistry.Create;
try
TempReg.RootKey:=HKEY_LOCAL_MACHINE;
if TempReg.OpenKey('/Software/Microsoft/Windows/CurrentVersion/',false) then
begin
if tempreg.ValueExists('ProductId') then
begin
TempValue:=TempReg.ReadString('ProductId');
Label1.Caption:=TempValue;
end
else
ShowMessage('ProductID is not exist!');
end;
finally
TempReg.CloseKey;
TempReg.Free;
end;
end;

下面代码程序,label却不显示,为什么?

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls,Registry;

type
TForm1 = class(TForm)
Label1: TLabel;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
var
TempReg:TRegistry;
TempValue:string;
begin
TempReg:=TRegistry.Create;
try
TempReg.RootKey:=HKEY_LOCAL_MACHINE;
if TempReg.OpenKey('/Software/Microsoft/Windows/CurrentVersion/',false) then
begin
if tempreg.ValueExists('ProductId') then
begin
TempValue:=TempReg.ReadString('ProductId');
Label1.Caption:=TempValue;
end
else
ShowMessage('ProductID is not exist!');
end;
finally
TempReg.CloseKey;
TempReg.Free;
end;
end;
end.

end.

你没有给OnCreate事件赋值！！

你，你，你，，你怎么问起这个问题了，，，你看你的原码：

implementation

{$R *.dfm}

var
TempReg:TRegistry;
TempValue:string;
begin
TempReg:=TRegistry.Create;
try
TempReg.RootKey:=HKEY_LOCAL_MACHINE;
。。。
。。。

你这段代码郎个让编译器处理嘛，，，前面少了函数头塞，，，

在implementation 后面的是实现部分，，，你不可以把函数头丢了，，

至于这段代码：
我原封不动的用，没有错：我的完整单元代码如下：
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls,Registry;

type
TForm1 = class(TForm)
Label1: TLabel;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
TempReg:TRegistry;
TempValue:string;
begin
TempReg:=TRegistry.Create;
try
TempReg.RootKey:=HKEY_LOCAL_MACHINE;
if TempReg.OpenKey('/Software/Microsoft/Windows/CurrentVersion/',false) then
begin
if tempreg.ValueExists('ProductId') then
begin
TempValue:=TempReg.ReadString('ProductId');
Label1.Caption:=TempValue;
end
else
ShowMessage('ProductID is not exist!');
end;
finally
TempReg.CloseKey;
TempReg.Free;
end;
end;


end.

兄台：你问的问题实在是太入门级的问题了，，，你是不是才开始用DELPHI？？

HeyTommy兄台,你编译一下,该程序为何Label1不显示应该显示的内容?虽然语法没错,但却没有功能?

好嘛，，给个信箱，我把编译过的整个工程给你，你自己去看看吧！！！

我的平台是win2000 professional，delphi 6

QQ:108438328

我仔细看了，呵呵，，，，

你看你的整个单元的结尾：
怎么有行这样的语句呢？

end.

end.

只需要一个[red]end.[/red]的嘛，，它表示的是一个单元中的程序的结束的嘛， ，，只能要一个
，多了要出错！！！！

多复制了一个,我复制了一百万个,编译通过,没影响啊!呵呵.......

你怎么能这么想呢？
你是可以加一摩多的结尾，，，编译器会给忽略，，，但也太那个了吧？？

HeyTommy兄台,再次请你编译一下,该程序为何Label1不显示应该显示的内容?虽然语法没错,但却没有功能?

根本不是这个原因, 你到Form的事件里双击一下OnCreate就可以了