Question

我正在尝试添加一个文本框注释，其文本具有指定的字体和大小。代码如下：

void addTextBox(string inputPath,string outputPath)
{
    PdfReader pdfReader = new PdfReader(inputPath);
    PdfStamper pdfStamper = new PdfStamper(pdfReader, new FileStream(outputPath, FileMode.Create));
    PdfContentByte pcb = new PdfContentByte(pdfStamper.Writer);
    BaseFont baseFont = FontFactory.GetFont(FontFactory.HELVETICA).BaseFont;
    float fontsize = 32;
    pcb.SetFontAndSize(baseFont, fontsize);
    PdfAnnotation textbox = PdfAnnotation.CreateFreeText(pdfStamper.Writer, new iTextSharp.text.Rectangle(200, 200, 3000, 3000), "Here is a Textbox", pcb);
    pdfStamper.AddAnnotation(textbox, 1);
    pdfStamper.Close();
}

pcb.SetFontAndSize()来电正在抛出异常：

Object reference not set to an instance of an object.

pcb已经在发生此错误时被实例化，fontsize已成功分配其数值，那么这里的未分配对象是什么？

Answer 1

Replace PdfContentByte(pdfStamper.Writer) with pdfStamper.GetOverContent(1) and the problem will disappear.

PdfContentByte.SetFontAndSize（）抛出“对象引用未设置为对象的实例”

1 个答案: