Question

对不起，如果这是错误的地方问。我有两段代码给我：

IdHTTP1->Head("http://dsrt.dyndns.org/files/MAIN.zip");
Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Date));
Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Expires));
Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->LastModified));

还有这个：

TDateTime dt;
AnsiString str = DateToStr(dt);
IdHTTP1->Head("http://dsrt.dyndns.org/files/MAIN.zip");
if(DateToStr(IdHTTP1->Response->Date) != str)
  Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Date));
if(DateToStr(IdHTTP1->Response->Expires) != str)
  Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Expires));
if(DateToStr(IdHTTP1->Response->LastModified) != str)
  Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->LastModified));

不知何故，它应该返回文件上传的日期。但我不知道如何让c ++ builder编译它。我得到语法错误和＆＃34;多个memo1东西＆＃34;错误。请帮忙。

Answer 1

TMemo是Embarcadero可视化UI组件。 TIdHTTP是Indy Project的一个组件，它预装在Delphi和C ++ Builder中。

您获得的代码是与UI相关的代码，因此请为其创建UI。在C ++ Builder IDE中，创建一个新的TForm类，在其上放置TMemo并将其命名为Memo1，然后删除TIdHTTP组件并将其命名为{{ 1}}，然后使用类似按钮IdHTTP1处理程序来调用HTTP代码，例如：

Unit1.h：

OnClick

Unit1.cpp：

//---------------------------------------------------------------------------

#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <System.Classes.hpp>
#include <Vcl.Controls.hpp>
#include <Vcl.StdCtrls.hpp>
#include <Vcl.Forms.hpp>
#include <IdHTTP.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:    // IDE-managed Components
    TMemo *Memo1;
    TButton *Button1;
    TButton *Button2;
    TIdHTTP *IdHTTP1;
    void __fastcall Button1Click(TObject *Sender);
    void __fastcall Button2Click(TObject *Sender);
private:    // User declarations
public:     // User declarations
    __fastcall TForm1(TComponent* Owner);
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif

话虽如此，使用字符串来比较日期/时间值通常不是一个好主意。此类字符串受区域设置问题的影响。您正在使用依赖于本地计算机当前区域设置的转换功能，而不是HTTP的标准化日期/时间格式。您使用的//--------------------------------------------------------------------------- #include <vcl.h> #pragma hdrstop #include "Unit1.h" #include <System.Sysutils.hpp> //--------------------------------------------------------------------------- #pragma package(smart_init) #pragma resource "*.dfm" TForm1 *Form1; //--------------------------------------------------------------------------- __fastcall TForm1::TForm1(TComponent* Owner) : TForm(Owner) { } //--------------------------------------------------------------------------- void __fastcall TForm1::Button1Click(TObject *Sender) { IdHTTP1->Head("http://dsrt.dyndns.org/files/MAIN.zip"); Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Date)); Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Expires)); Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->LastModified)); } //--------------------------------------------------------------------------- void __fastcall TForm1::Button2Click(TObject *Sender) { TDateTime dt = ...; // assign some value // see functions such as Date(), Now(), EncodeDateTime(), etc, // or use the TDateTimePicker component... System::String str = DateToStr(dt); IdHTTP1->Head("http://dsrt.dyndns.org/files/MAIN.zip"); if (DateToStr(IdHTTP1->Response->Date) != str) Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Date)); if (DateToStr(IdHTTP1->Response->Expires) != str) Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->Expires)); if (DateToStr(IdHTTP1->Response->LastModified) != str) Memo1->Lines->Add(DateTimeToStr(IdHTTP1->Response->LastModified)); } //---------------------------------------------------------------------------属性为TIdHTTP个值，其中TDateTime已将HTTP提供的值转换为本地日期/时间的二进制值（基于本地计算机＆＃39; s当前时区）。您可以按原样比较这些值，而不必担心任何字符串转换，例如：

TIdHTTP

进行void __fastcall TForm1::Button2Click(TObject *Sender) { TDateTime dt = ...; // assign some value // see functions such as Date(), Now(), EncodeDateTime(), etc, // or use the TDateTimePicker component... IdHTTP1->Head("http://dsrt.dyndns.org/files/MAIN.zip"); if (IdHTTP1->Response->Date != dt) { //... } if (IdHTTP1->Response->Expires != dt) { //... } if (IdHTTP1->Response->LastModified != dt) { //... } }比较比字符串比较更准确，更可靠。您不仅限于TDateTime和==运算符，还可以使用!=和<运算符：

C ++ builder（不知道如何处理这段代码）

1 个答案: