iText 7 CreateText Box错误:对象引用未设置为对象的实例
创建新的PDF文档时会发生以下情况。在第三页上创建第一个文本字段时出错。在前两个页面上创建了多个字段,没有任何问题iText 7 CreateText Box错误:对象引用未设置为对象的实例,itext,itext7,Itext,Itext7,创建新的PDF文档时会发生以下情况。在第三页上创建第一个文本字段时出错。在前两个页面上创建了多个字段,没有任何问题 Image processing failed - Exception: Object reference not set to an instance of an object. Stack Trace: at KernelExtensions.Get[TKey,TValue](IDictionary`2 col, TKey key) at iText.Kernel
Image processing failed - Exception: Object reference not set to an instance of an object.
Stack Trace: at KernelExtensions.Get[TKey,TValue](IDictionary`2 col, TKey key)
at iText.Kernel.Pdf.PdfDictionary.Get(PdfName key, Boolean asDirect)
at iText.Kernel.Pdf.PdfDictionary.GetAsArray(PdfName key)
at iText.Kernel.Pdf.PdfPage.GetAnnotations()
at iText.Kernel.Pdf.Annot.PdfAnnotation.GetPage()
at iText.Forms.Fields.PdfFormField.RegenerateField()
at iText.Forms.Fields.PdfFormField.SetValue(String value, Boolean generateAppearance)
at iText.Forms.Fields.PdfFormField.SetValue(String value)
at iText.Forms.Fields.PdfFormField.CreateText(PdfDocument doc, Rectangle rect, String name, String value, PdfFont font, Single fontSize)
at MikeA.CoreLogic.CreatePDFFile(List`1 imageList, Int32 nImgCnt, SqlConnection sqlPagesConnect) in C:\ef-pdfGen0\CoreLogic.cs:line 387
相关代码:
private void CreatePDFFile(List<byte[]> imageList, int nImgCnt, SqlConnection sqlPagesConnect)
{
String sFontName = "";
Double nFontWeight = 0.0;
Boolean bFontBold = false;
PdfWriter pdfWriter = new PdfWriter("C:\\tmp\\images\\MikeA.pdf");
using (PdfDocument pdfDoc = new PdfDocument(pdfWriter))
{
int nPageNdx = 0;
Document doc = new Document(pdfDoc);
doc.SetMargins(0,0,0,0);
while (nImgCnt > nPageNdx)
// while(nPageNdx < 1)
{
iText.Layout.Element.Image pdfImage = new iText.Layout.Element.Image(iText.IO.Image.ImageDataFactory.Create(imageList[nPageNdx], true));
float fImageWidth = pdfImage.GetImageWidth();
float fImageHeight = pdfImage.GetImageHeight();
PageSize pageSize = new PageSize(fImageWidth, fImageHeight);
PdfPage pdfPage = pdfDoc.AddNewPage(pageSize);
doc.Add(pdfImage);
==> SQL DB setup
try
{
while (sqlPagesReader.Read())
{
==> Setting variables from the database
// Reminder:O orientation is 0,0 at top left of page. PDF orientation is 0.0 bottom left of page.
// x and y must be scaled to the image width and height.
float fTextBoxWidth = ((float)nRightPos - (float)nLeftPos) * fImageWidth;
float fTextBoxHeight = ((float)nBottomPos - (float)nTopPos) * fImageHeight;
float fTextBoxX = fImageWidth * (float)nLeftPos;
float fTextBoxY = fImageHeight * (float)((1.0 - nBottomPos));
iText.Kernel.Geom.Rectangle textBoxRect = new iText.Kernel.Geom.Rectangle(fTextBoxX, fTextBoxY, fTextBoxWidth, fTextBoxHeight);
Line 387 var myPdfField = PdfTextFormField.CreateText(pdfDoc, textBoxRect, sAssignedName, "abc", fieldFont, (float)nFontWeight);
PdfAcroForm.GetAcroForm(pdfDoc, true).AddField(myPdfField);
}
}
finally
{
((IDisposable)sqlPagesCommand).Dispose();
((IDisposable)sqlPagesReader).Dispose();
}
nPageNdx++;
doc.Flush();
} // While nImgCnt
doc.Close(); // Writes the PDF to disk
pdfDoc.Close();
}
} // End CreatePDFFile
private void CreatePDFFile(List-imageList、int-nImgCnt、SqlConnection-sqlPagesConnect)
{
字符串sFontName=“”;
双倍重量=0.0;
布尔bFontBold=false;
PdfWriter PdfWriter=新的PdfWriter(“C:\\tmp\\images\\MikeA.pdf”);
使用(PdfDocument pdfDoc=新PdfDocument(pdfWriter))
{
int-nPageNdx=0;
单据单据=新单据(pdfDoc);
文件设置边距(0,0,0,0);
而(nImgCnt>nPageNdx)
//而(nPageNdx<1)
{
iText.Layout.Element.Image pdfImage=new iText.Layout.Element.Image(iText.IO.Image.ImageDataFactory.Create(imageList[nPageNdx],true));
float-fImageWidth=pdfImage.GetImageWidth();
float-fImageHeight=pdfImage.GetImageHeight();
PageSize PageSize=新页面大小(fImageWidth、fImageHeight);
PdfPage PdfPage=pdfDoc.AddNewPage(页面大小);
文件添加(pdfImage);
==>SQL数据库设置
尝试
{
while(sqlPagesReader.Read())
{
==>设置数据库中的变量
//提醒:页面左上角的O方向为0,0。PDF方向为页面左下角的0.0。
//x和y必须缩放到图像的宽度和高度。
浮动fTextBoxWidth=((浮动)nRightPos-(浮动)nLeftPos)*fImageWidth;
浮动fTextBoxHeight=((浮动)nBottomPos-(浮动)nTopPos)*fImageHeight;
float fTextBoxX=fImageWidth*(float)nLeftPos;
浮动fTextBoxY=fImageHeight*(浮动)((1.0-nBottomPos));
iText.Kernel.Geom.Rectangle textBoxRect=新的iText.Kernel.Geom.Rectangle(fTextBoxX,fTextBoxY,fTextBoxWidth,fTextBoxHeight);
第387行var myPdfField=PdfTextFormField.CreateText(pdfDoc,textBoxRect,sAssignedName,“abc”,fieldFont,(float)nFontWeight);
PdfAcroForm.GetAcroForm(pdfDoc,true).AddField(myPdfField);
}
}
最后
{
((IDisposable)sqlPagesCommand.Dispose();
((IDisposable)sqlPagesReader.Dispose();
}
nPageNdx++;
doc.Flush();
}//当nImgCnt
doc.Close();//将PDF写入磁盘
pdfDoc.Close();
}
}//结束CreatePdfile
插入pdfPage.Flush();在“PdfPage PdfPage=pdfDoc.AddNewPage(pageSize);”语句之后,将第一个文本框添加到第一个页面时,会导致相同的错误
如何更正错误?我成功地使用了以下解决方法:
PdfPage pdfPage = pdfDoc.AddNewPage();
iText.Kernel.Geom.Rectangle pageRect = pdfPage.GetPageSize();
PdfCanvas pdfCanvas = new PdfCanvas(pdfPage);
iText.IO.Image.ImageData pdfImageData = ImageDataFactory.Create(imageList[nPageNdx]);
pdfCanvas.AddImage(pdfImageData, 0, 0, pageRect.GetWidth(), false);
这是添加图像的另一种方法