我尝试从数据表创建PDF报告。其中一列内容图像。如何从数据表中提取图像并插入PDF表格？我正在使用iTextShap版本5.4.2.0。这是代码：
public void Report(DataTable dt, string output)
{
Document doc = new Document(PageSize.LETTER, 50, 50, 80, 50);
PdfWriter PDFWriter = PdfWriter.GetInstance(doc, new FileStream(output, FileMode.Create));
PDFWriter.ViewerPreferences = PdfWriter.PageModeUseOutlines;
iTextSharp.text.Font hel8 = FontFactory.GetFont(BaseFont.HELVETICA, 8);
doc.Open();
PdfPTable table = new PdfPTable(dt.Columns.Count);
float[] widths = new float[] { 1.2f, 1.2f, 1.2f, 1.2f, 1f, 4f, 1f, 4f };
table.SetWidths(widths);
table.WidthPercentage = 100;
PdfPCell cell = new PdfPCell(new Phrase("NewCells"));
cell.Colspan = dt.Columns.Count;
foreach (DataColumn c in dt.Columns)
{
table.AddCell(new Phrase(c.ColumnName, hel8));
}
foreach (DataRow r in dt.Rows)
{
if (dt.Rows.Count > 0)
{
table.AddCell(new Phrase(r[0].ToString(), hel8));
table.AddCell(new Phrase(r[1].ToString(), hel8));
table.AddCell(new Phrase(r[2].ToString(), hel8));
table.AddCell(new Phrase(r[3].ToString(), hel8));
table.AddCell(new Phrase(r[4].ToString(), hel8));
table.AddCell(new Phrase(r[5].ToString(), hel8));
byte[] byt = (byte[])r[6];
MemoryStream ms = new MemoryStream(byt);
System.Drwaing.Image sdi = System.Drawing.Image.FromStream(ms);
Image img = Image.GetInstance(sdi); <-- this is the problem code
table.AddCell(img);
table.AddCell(new Phrase(r[7].ToString(), hel8));
}
}
doc.Add(table);
}
doc.Close();
}
更新： @nekno，您的所有建议都已完成。
但我仍然需要在线上纠正施法：
byte[] byt = (byte[])r[6];
它给了我VS2008的一个施法例外。所以我添加了转换函数（从stackoverflow中取出）：
byte[] ImageToByte(System.Drawing.Image img)
{
byte[] byteArray = new byte[0];
using (MemoryStream stream = new MemoryStream())
{
img.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
stream.Close();
byteArray = stream.ToArray();
}
return byteArray;
}
修改了代码：
byte[] byt = ImageToByte((System.Drawing.Image)dt.Rows[e][6]);
感谢。
答案 0 :(得分：6)
究竟是什么问题？使用问题代码时会发生什么？
尝试其他Image.GetInstance()重载之一：
您可以直接传递字节数组：
byte[] byt = (byte[])r[6];
Image img = Image.GetInstance(byt);
或者您可以传递Stream：
byte[] byt = (byte[])r[6];
MemoryStream ms = new MemoryStream(byt);
Image img = Image.GetInstance(ms);
或者您可以向iTextSharp提供有关图像格式的更多信息：
byte[] byt = (byte[])r[6];
MemoryStream ms = new MemoryStream(byt);
System.Drawing.Image sdi = System.Drawing.Image.FromStream(ms);
Image img = Image.GetInstance(sdi, ImageFormat.Png);
如果您的列可以转换为System.Drawing.Image，那么您可以直接使用它：
Image img = Image.GetInstance((System.Drawing.Image)r[6], System.Drawing.Imaging.ImageFormat.Png);
答案 1 :(得分：3)
我已经建议了如何显示如何将图像添加到PDF中的步骤，下面给出了代码片段，展示了如何使用iTextsharp在您的PDF中添加徽标，请按照以下步骤操作：
希望它对你有用!!!
protected void btnPDF_Click(object sender, ImageClickEventArgs e)
{
DataTable dtn = new DataTable();
dtn = GetDataTable();
dtPDF = dtn.Copy();
for (int i = 0; i <= dtn.Rows.Count - 1; i++)
{
ExportToPdf(dtPDF);
}
}
public void ExportToPdf(DataTable myDataTable)
{
Document pdfDoc = new Document(PageSize.A4, 10, 10, 10, 10);
try
{
PdfWriter.GetInstance(pdfDoc, System.Web.HttpContext.Current.Response.OutputStream);
pdfDoc.Open();
Chunk c = new Chunk("" + System.Web.HttpContext.Current.Session["CompanyName"] + "", FontFactory.GetFont("Verdana", 11));
Paragraph p = new Paragraph();
p.Alignment = Element.ALIGN_CENTER;
p.Add(c);
pdfDoc.Add(p);
string clientLogo = Server.MapPath(".") + "/logo/tpglogo.jpg";
string imageFilePath = Server.MapPath(".") + "/logo/tpglogo.jpg";
iTextSharp.text.Image jpg = iTextSharp.text.Image.GetInstance(imageFilePath);
//Resize image depend upon your need
jpg.ScaleToFit(80f, 60f);
//Give space before image
jpg.SpacingBefore = 0f;
//Give some space after the image
jpg.SpacingAfter = 1f;
jpg.Alignment = Element.HEADER;
pdfDoc.Add(jpg);
Font font8 = FontFactory.GetFont("ARIAL", 7);
DataTable dt = myDataTable;
if (dt != null)
{
//Craete instance of the pdf table and set the number of column in that table
PdfPTable PdfTable = new PdfPTable(dt.Columns.Count);
PdfPCell PdfPCell = null;
for (int rows = 0; rows < dt.Rows.Count; rows++)
{
for (int column = 0; column < dt.Columns.Count; column++)
{
PdfPCell = new PdfPCell(new Phrase(new Chunk(dt.Rows[rows][column].ToString(), font8)));
PdfTable.AddCell(PdfPCell);
}
}
//PdfTable.SpacingBefore = 15f; // Give some space after the text or it may overlap the table
pdfDoc.Add(PdfTable); // add pdf table to the document
}
pdfDoc.Close();
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment; filename= SampleExport.pdf");
System.Web.HttpContext.Current.Response.Write(pdfDoc);
Response.Flush();
Response.End();
//HttpContext.Current.ApplicationInstance.CompleteRequest();
}
catch (DocumentException de)
{
System.Web.HttpContext.Current.Response.Write(de.Message);
}
catch (IOException ioEx)
{
System.Web.HttpContext.Current.Response.Write(ioEx.Message);
}
catch (Exception ex)
{
System.Web.HttpContext.Current.Response.Write(ex.Message);
}
}