IdHTTPServer允许跨域访问

procedure TMain.idHttpServerCommandGet(AContext: TIdContext; ARequestInfo: TIdHTTPRequestInfo;  AResponseInfo: TIdHTTPResponseInfo);
begin
    AResponseInfo.CustomHeaders.Add('Access-Control-Allow-Origin:*');
    AResponseInfo.CustomHeaders.Add('Access-Control-Allow-Headers:*');
    AResponseInfo.CustomHeaders.Add('Access-Control-Allow-Method:*');
end;