c# – 将byte []数组的一部分复制到PDFReader中

所以我有一个设置大小的字节数组,对于这个例子,我会说新字节[400000].在这个数组中,我将放置不同大小的pdf(小于400000).

伪代码将是：

public void Run()
{
    byte[] fileRetrievedFromDatabase = new byte[400000];
    foreach (var document in documentArray)
    {
        // Refill the file with data from the database
        var currentDocumentSize = PopulateFileWithPDFDataFromDatabase(fileRetrievedFromDatabase);

        var reader = new iTextSharp.text.pdf.PdfReader(fileRetrievedFromDatabase.Take((int)currentDocumentSize ).ToArray());
        pageCount = reader.NumberOfPages;
        // DO ADDITIONAL WORK
    } 
}

private int PopulateFileWithPDFDataFromDatabase(byte[] fileRetrievedFromDatabase)
{
    // DataAccessCode Goes here
    int documentSize = 0;
    int bufferSize = 100;                   // Size of the BLOB buffer.
    byte[] outbyte = new byte[bufferSize];  // The BLOB byte[] buffer to be filled by GetBytes.

    myReader = logoCMD.ExecuteReader(CommandBehavior.SequentialAccess);

    Array.Clear(fileRetrievedFromDatabase,fileRetrievedFromDatabase.Length);

    if (myReader == null)
    {
        return;
    }

    while (myReader.Read())
    {
        documentSize = myReader.GetBytes(0,null,0);

        // Reset the starting byte for the new BLOB.
        startIndex = 0;

        // Read the bytes into outbyte[] and retain the number of bytes returned.
        retval = myReader.GetBytes(0,startIndex,outbyte,bufferSize);

        // Continue reading and writing while there are bytes beyond the size of the buffer.
        while (retval == bufferSize)
        {
            Array.Copy(outbyte,fileRetrievedFromDatabase,retval);

            // Reposition the start index to the end of the last buffer and fill the buffer.
            startIndex += retval;
            retval = myReader.GetBytes(0,bufferSize);
        }
    }

    return documentSize;
}

以上代码的问题是,当我尝试访问PDF阅读器时,我一直收到“未找到重建预告片.原始错误：未找到PDF startxref”错误.我相信这是因为字节数组太长并且尾随0.但由于我正在使用字节数组,所以我不会在LOH上不断构建新对象,我需要这样做.

那么我如何获得我需要的数组并将其发送到PDFReader呢？

更新

所以我查看了源代码,发现我的实际代码中有一些变量令人困惑.我基本上在循环的每次迭代中重用fileRetrievedFromDatabase对象.由于它通过引用传递,它被清除(设置为全零),然后填充PopulateFileWithPDFDataFromDatabase.然后,此对象用于创建新PDF.

如果我没有这样做,将在每次迭代中创建一个新的大字节数组,并且Large Object Heap会变满并最终抛出OutOfMemory异常.