託管的c + +從資源提取文件，錯誤的文件大小

Question

嗨即時嘗試從我的嵌入式資源提取文件，但問題是文件大小不正確，它應該是大約3500KB，但它出來爲5850KB或所以。

  Assembly ^myAssembly = Assembly::GetExecutingAssembly(); 
     Stream ^myStream = myAssembly->GetManifestResourceStream("cool.exe"); 
     FileStream^ fs = gcnew FileStream("cool.exe",FileMode::Append,FileAccess::Write,FileShare::Write); 
     StreamReader^ Reader = gcnew StreamReader(myStream); 
     StreamWriter^ Writer = gcnew StreamWriter(fs); 
     Writer->Write(Reader->ReadToEnd()); 
     fs->Close(); 

這是所編輯的一個：

Assembly ^myAssembly = Assembly::GetExecutingAssembly(); 
     Stream ^myStream = myAssembly->GetManifestResourceStream("cool.exe"); 
     FileStream^ fs = gcnew FileStream("cool.exe",FileMode::Append,FileAccess::Write,FileShare::Write); 
     StreamReader^ Reader = gcnew StreamReader(myStream); 
     StreamWriter^ Writer = gcnew StreamWriter(fs); 
     //Writer->Write(Reader->ReadToEnd()); 

     array<Byte^>^ buffer = gcnew array<Byte^>(256); 

     while (true) 
     { 

      int read = Reader->Read(buffer,0,buffer->Length); 
      if(read <= 0) 
      { 
       return; 
      } 
      Writer->Write(buffer,0,read); 
     } 

     fs->Close(); 

SOLOUTION

public: static void CopyStream(Stream^ input, Stream^ output) 
     {  

      array<Byte>^ buffer = gcnew array<Byte>(32768); 

      long TempPos = input->Position; 

      while (true)   
      {   
       int read = input->Read(buffer, 0, buffer->Length);   
       if (read <= 0) break;   
       output->Write (buffer, 0, read);  
      }  
      input->Position = TempPos;// or you make Position = 0 to set it at the start 
     } 

然後使用它：

Assembly ^myAssembly = Assembly::GetExecutingAssembly(); 
     Stream ^myStream = myAssembly->GetManifestResourceStream("cool.exe"); 
     FileStream^ fs = gcnew FileStream("cool.exe",FileMode::Append,FileAccess::Write,FileShare::Write); 

     CopyStream(myStream,fs); 
     fs->Close(); 

這將使正確的文件和正確的文件大小=）

Answer 1

二進制數據不是文本。

StreamReader正在將您的數據轉換爲UTF8，這不是您想要的。
您需要通過調用Write和Read來複制原始字節。