领悟旧事--木头云之

XE10 C++Builder采用FTP下载文件到本地

来源：http://www.xx0594.com/
时间：2023-8-4
作者：浏览人数:398

添加一个IdHTTP控件命名为IdHTTP1、一个进度条ProgressBar控件，命名为DownLoad_ProgressBar。
void __fastcall TTabbedForm::DownloadFile(AnsiString URL,AnsiString sFileName)
{
TMemoryStream *ms=new TMemoryStream();
bCanDownload = true;
try{
  DownLoad_ProgressBar->Visible=true;
  try{
            Application->ProcessMessages();
   IdHTTP1->Get(URL,ms);//注意，下载的只能是图片格式的扩展名如png/jpg...而不能是其它的。
   ms->SaveToFile(sFileName);
  }
  catch(Exception &ee)//__except(...)
  {
   ToastLog(U"错误："+ee.Message);//自定义函数。
   bCanDownload =false;DownLoad_ProgressBar->Visible=false;
  }
}
__finally{ //单个文件不能下载。
  if(!bCanDownload)ToastLog(U"下载错误，请检查设置！");
  else{
   ToastLog(U"下载完成！");
   //InstallAPK("/storage/emulated/0/057Lmq/App/signIn.apk");
  }
  delete ms;
}
}
//---------------------------------------------------------------------------
//显示下载进度
void __fastcall TTabbedForm::IdHTTP1Work(TObject *ASender, TWorkMode AWorkMode, __int64 AWorkCount)

{
Application->ProcessMessages();//注意，要处理消息，否则无法显示进度。
DownLoad_ProgressBar->Value= AWorkCount;
}
//---------------------------------------------------------------------------
void __fastcall TTabbedForm::IdHTTP1WorkBegin(TObject *ASender, TWorkMode AWorkMode,
__int64 AWorkCountMax)
{
DownLoad_ProgressBar->Max = AWorkCountMax;
}
//---------------------------------------------------------------------------

void __fastcall TTabbedForm::IdHTTP1WorkEnd(TObject *ASender, TWorkMode AWorkMode)

{
DownLoad_ProgressBar->Visible=false;
DownLoad_ProgressBar->Value=0;
DownLoad_ProgressBar->Max = 10;
}
//---------------------------------------------------------------------------

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