TIdHTTP 返回的 JSON 无法解码

Question

我有以下代码：

    var
      MemoryStream1: TMemoryStream;
      IdHTTP1: TIdHTTP;
      Bytes1: TBytes;
      s1: string;
    begin             
      IdHTTP1 := TIdHTTP.Create(nil);
      MemoryStream1 := TMemoryStream.Create;
      IdHTTP1.Get('https://restcountries.eu/rest/v2/all', MemoryStream1);
      MemoryStream1.Position := 0;
      MemoryStream1.SaveToFile('C:\Temp\MemoryStream1.txt');
      MemoryStream1.Position := 0;
      SetLength(Bytes1, MemoryStream1.Size);
      MemoryStream1.Read(Bytes1[0], MemoryStream1.Size);
      s1 := TEncoding.UTF8.GetString(Bytes1);

在最后一行失败并显示消息“目标多字节代码页中的 unicode 字符不存在映射”

但是，我可以在 HttpAnalyzer 中清楚地看到返回的 JSON。

文件“C:\Temp\MemoryStream1.txt”以十六进制“1F8B0800000000000003DC9BED6F1BB7”开头，而我期待与 { - 左大括号 - 作为第一个字符相对应的内容

当我尝试 s1 := TEncoding.Unicode.GetString(Bytes1);

字符串 s1 包含“中文”字符。

Answer 1

我解决了。显然，gzip 没有解压缩。必须自己做。如下：

    var
      IdHTTP1: TIdHTTP;
      a1: AnsiString;
      s1: string;
      MemoryStream1, MemoryStream2: TMemoryStream;
    begin             
      Screen.Cursor := crHourGlass;
      IdHTTP1 := TIdHTTP.Create(nil);
      MemoryStream1 := TMemoryStream.Create;
      MemoryStream2 := TMemoryStream.Create;
      IdHTTP1.Get('https://restcountries.eu/rest/v2/all', MemoryStream1);
      MemoryStream1.Position := 0;
      IdCompressorZLib1.DecompressGZipStream(MemoryStream1, MemoryStream2);
      FreeAndNil(MemoryStream1);
      MemoryStream2.Position := 0;
      SetLength(a1, MemoryStream2.Size);
      MemoryStream2.Read(a1[1], MemoryStream2.Size);   
     //  AnsiString a1 now contains the decompressed data