无法使用ASP.net在浏览器中打开文件

Question

我需要大师的帮助才能在浏览器中打开文件。我正在使用以下代码片段从外部CMS获取文件，然后在浏览器中打开它。但它抛出异常：System.IO.FileNotFoundException: Could not find file 'C:\Users\test\Documents\Visual Studio 2010\Projects\connectToABC\DownloadFileFromABCWEB\System.Byte[]'.

代码段

try
{
    var searchParams = new ABCLib.ABCSearchParameters();
    searchParams.WebServiceURL = serverUrl;
    searchParams.MyCredentials = new NetworkCredential("xxxxx", "xxxx");

    var contentItems = ABCLib.ABC.SearchABCContent(searchParams);

    if ((contentItems != null) && (contentItems.Length > 0))
    {
        var fileContent = ABCLib.ABCGetFile.GetABCFileContentByName(searchParams.WebServiceURL, searchParams.MyCredentials, "QAABC1000000146789");
        string filePath = Server.MapPath(fileContent.ToString());
        WebClient user = new WebClient();
        Byte[] FileBuffer = user.DownloadData(filePath);

        if (FileBuffer != null)
        {
            Response.ContentType = "application/pdf";
            Response.AddHeader("content-length", FileBuffer.Length.ToString());
            Response.BinaryWrite(FileBuffer);
        }  
    }
}
catch (Exception)
{
    throw;
}