主题：iTextSharp 报错请教

代码如下

        Dim cb As new iTextSharp.text.Rectangle(595,257)  '纸张大小
        Dim dc As new iTextSharp.text.Document(cb)

        Dim a as integer
        Dim ft  As String = "C:\WINDOWS\Fonts\msyh.TTF"      '  ITextSharp支持中文的字体
        Dim ift As iTextSharp.text.pdf.BaseFont = iTextSharp.text.pdf.BaseFont.CreateFont(ft, _
        iTextSharp.text.pdf.BaseFont.IDENTITY_H, iTextSharp.text.pdf.BaseFont.NOT_EMBEDDED)
        '创建实例,PDF 文件将会保存到这里
        Dim writer As iTextSharp.text.pdf.PdfWriter  = iTextSharp.text.pdf.PdfWriter.GetInstance(dc,new System.IO.FileStream(file,System.IO.FileMode.Create))
        '打开文档
        dc.Open()
       
        Dim sumyes As Integer =   Math.Ceiling(FileSys.GetFiles("d:\cutoff\").Count /3) * 10  + 100    '读文件名 从小到大
        For p As Integer = 1 To sumyes
            If FileSys.FileExists("d:\cutoff\" & "test" & p & ".jpg") Then
                Dim str As String = "d:\cutoff\" & "test" & p & ".jpg"
                Dim ifo As new FileInfo(str)
                If str.Contains("jpg")  AndAlso ifo.Length > 30000 Then  'ifo.Length > 50000 让文件的大小大于 50k   避免空页面加载
                    a = a + 1
                    Dim  itIm2 As iTextSharp.Text.Image  =  iTextSharp.text.Image.getInstance(str)     '定义ITextSharp图片
                    itIm2.SetAbsolutePosition(20,1)        '设置图片坐标:原点(0,0)为左下角!
                    itIm2.ScalePercent(20)
                    dc.add(itIm2)
                    dc.newpage
                End If
            End If
        Next
        dc.Close()

此主题相关图片如下：捕获.jpg

偶尔会提示以上内容， 应该是内存不足吧！  不知道怎么处理好,请指点下