Question

我需要将数据从DLL发送到App，其中＆＃34; data＆＃34;是一个变种数组。

我尝试使用SendMessage / WM_COPYDATA，没有运气！

这是我到目前为止所得到的：

// sender's side (dll)
procedure sendData(apphandle: THandle);
var V: Variant;
begin
    V = VarArrayOf([1,'Some Text', 123.45, true]);
    copyDataStruct.dwData := 100;
    copyDataStruct.cbData := ?; <-- what here?
    copyDataStruct.lpData := ?; <-- and here? how to put "V"?
    SendMessage(apphandle, WM_COPYDATA, Integer(apphandle), Integer(@copyDataStruct)) ;
end;


// receiver's side (same app where dll was called)
procedure WMCopyData(var Msg: TWMCopyData) ;
var V : Variant;
begin
    if (Msg.CopyDataStruct.dwData = 100) then
    begin
        V := Msg.CopyDataStruct.lpData; <-- how to get "V" from lpData?
        // do some work with "V" here...
    end;
end;

Answer 1

只要app和DLL使用相同版本的RTL，并且您在同一进程内传递Variant，就可以将其作为指针传递，例如：

procedure sendData(AppHandle: HWND);
var
  V: Variant;
begin
  V := VarArrayOf([1,'Some Text', 123.45, true]);
  copyDataStruct.dwData := 100;
  copyDataStruct.cbData := SizeOf(Pointer);
  copyDataStruct.lpData := @V;
  SendMessage(AppHandle, WM_COPYDATA, WPARAM(AppHandle), LPARAM(@copyDataStruct));
end;

procedure WMCopyData(var Msg: TWMCopyData);
var
  V : PVariant;
begin
  if (Msg.CopyDataStruct.dwData = 100) then
  begin
    V := PVariant(Msg.CopyDataStruct.lpData);
    // use V^ as needed...
  end;
end;

在这种情况下，您可以删除WM_COPYDATA，只需使用自定义窗口消息：

const
  WM_MYMSG = WM_APP + 1;

procedure sendData(AppHandle: HWND);
var
  V: Variant;
begin
  V := VarArrayOf([1,'Some Text', 123.45, true]);
  SendMessage(AppHandle, WM_MYMSG, 0, LPARAM(@V));
end;

procedure WMMyMsg(var Msg: TMessage);
var
  V : PVariant;
begin
  V := PVariant(Msg.LParam);
  // use V^ as needed...
end;

Delphi：如何使用Windows API将#Variant的变量数组发送到应用程序＆＃34; SendMessage＆＃34;？

1 个答案: