从Delphi访问包含VT_RECORD的VT_ARRAY的OleVariant [英] Accessing OleVariant containing VT_ARRAY of VT_RECORD from Delphi

问题描述

使用Delphi，我需要访问一个在数组中包含一个或多个记录的OleVariant.

Using Delp I need to access a OleVariant containing one or more records in an array.

我调用的方法返回一个VT_RECORD的VT_ARRAY，并且记录本身定义为:

The method I call returns a VT_ARRAY of VT_RECORD, and the records themselves are defined as:

struct StreamTimeInfo {
  unsigned int PID;
  LONGLONG PTS;
  LONGLONG TimeStamp;
}; 

我的代码是这样的:

procedure Test;
type
  TStreamInfo = record
    PID: Cardinal;
    PTS: Int64;
    TimeStamp: Int64;  
  end;
var
  Value: OleVariant
  StreamTime: TStreamInfo;
begin
  GetValue(Value); // Value holds a VT_ARRAY of VT_RECORD

  // How should I access the array of records in Delphi?
  // I've tried this to get to the first element:
  StreamTime := TStreamInfo(TVarData(Value).VPointer^);
end;

我不明白如何从Delphi中访问记录.

I do not understand how to access the records from Delphi.

非常感谢任何输入.

推荐答案

我以前从未做过，但是我认为这应该可行.

I've never done this before, but I think this should work.

type 
  TStreamInfoArray = array [0..MaxArrayCount-1] of TStreamInfo; 
  PStreamInfoArray = ^TStreamInfoArray; 
var 
  Value: Variant;
  p: PStreamInfoArray;
  StreamInfo: TStreamInfo;
begin 
  GetValue(Value);
  p := PStreamInfoArray(VarArrayLock(Value)); 
  try
    StreamInfo := p^[Index]; 
  finally
    VarArrayUnlock(Value); 
  end;
end; 

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