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我已将二进制编码图像存储到我的 SQL 数据库中。此二进制编码图像有另一个名为 MemberReportImage1 的文件，用于解码二进制图像。我可以在我的 webapp 页面上显示图像。但是，每当我尝试从数据库中获取图像时，它们都会显示 system.byte() ，因为它是直接从数据库中检索的并且尚未解码。因此，我想知道是否有任何方法可以检索解码的图像。

我已经尝试过这种方法，但最终没有成功

table.AddCell(Image1.Attributes["src"] = MemberReportImage1.aspx?);

这是我的解码文件

protected void Page_Load(object sender, EventArgs e)
    {
        string strQuery = "select image1 from MemberReport where memberreportid='" + Session["memberreportid"] + "'";
        SqlCommand cmd = new SqlCommand(strQuery);
        DataTable dt = GetData(cmd);
        if (dt != null)
        {
            download(dt);
        }
    }

    private DataTable GetData(SqlCommand cmd)
    {
        DataTable dt = new DataTable();
        SqlConnection con = new SqlConnection("Data Source=localhost; Initial Catalog=project; Integrated Security=True");
        SqlDataAdapter sda = new SqlDataAdapter();
        cmd.CommandType = CommandType.Text;
        cmd.Connection = con;
        try
        {
            con.Open();
            sda.SelectCommand = cmd;
            sda.Fill(dt);
            return dt;
        }
        catch
        {
            return null;
        }
        finally
        {
            con.Close();
            sda.Dispose();
            con.Dispose();
        }
    }

    private void download(DataTable dt)
    {
        Byte[] bytes = (Byte[])dt.Rows[0]["image1"];
        Response.Buffer = true;
        Response.Charset = "";
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        Response.ContentType = "image/jpg";
        //Response.ContentType = dt.Rows[0]["contenttype"].ToString();
        //Response.AddHeader("content-disposition", "attachment;filename=" + dt.Rows[0]["Name"].ToString());
        Response.BinaryWrite(bytes);
        Response.Flush();
        Response.End();
    }

这就是我从 MemberReportImage1 解码文件中检索解码图像的方式

if (!DDLCase.SelectedValue.Equals("-1"))
        {
            Session["memberreportid"] = DDLCase.SelectedValue;

            Image1.Attributes["src"] = "MemberReportImage1.aspx?";
            Image1.Attributes["height"] = "300";
            Image1.Attributes["width"] = "300";

            Image2.Attributes["src"] = "MemberReportImage2.aspx?";
            Image2.Attributes["height"] = "300";
            Image2.Attributes["width"] = "300";

            Image3.Attributes["src"] = "MemberReportImage3.aspx?";
            Image3.Attributes["height"] = "300";
            Image3.Attributes["width"] = "300";

            Image4.Attributes["src"] = "MemberReportImage4.aspx?";
            Image4.Attributes["height"] = "300";
            Image4.Attributes["width"] = "300";

            Image5.Attributes["src"] = "MemberReportImage5.aspx?";
            Image5.Attributes["height"] = "300";
            Image5.Attributes["width"] = "300";
        }

这是我的 PDF 按钮，我尝试从 MemberReportImage1 文件中获取解码图像

 protected void btnPDF_Click(object sender, EventArgs e)
    {

        var doc1 = new Document();
        var filename = "MyTestPDF" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".pdf";
        var output = new FileStream(Path.Combine("C:\\Users\\apr12mpsip\\Desktop\\New folder", filename), FileMode.Create);
        PdfWriter.GetInstance(doc1, output);
        doc1.Open();

        PdfPTable table = new PdfPTable(2);
        table.TotalWidth = 585f;
        table.LockedWidth = true;

        var logo = iTextSharp.text.Image.GetInstance(Server.MapPath("~/image/logo.jpg"));
        doc1.Add(logo);

        var titleFont = FontFactory.GetFont("Arial", 18, Font.BOLD);
        doc1.Add(new Paragraph("Official Report. Member Report ID : " + DDLCase.SelectedValue, titleFont));


        SqlConnection con = new SqlConnection("Data Source = localhost; Initial Catalog = project; Integrated Security = SSPI");

        SqlCommand cm = new SqlCommand("Select lro.fullname, lro.contact, mr.typeofcrime, mr.location,mr.crdatetime, pr.policeid,  pr.prdatetime, pr.policereport, mr.citizenreport, aor.officialreport from MemberReport mr, PoliceReport pr, LoginRegisterOthers lro, AdminOfficialReport aor where mr.memberreportid = '" + DDLCase.SelectedValue + "' and mr.memberreportid=pr.memberreportid and pr.policereportid=aor.policereportid", con);
        con.Open();
        SqlDataReader dr;

        dr = cm.ExecuteReader();

        if (dr.Read())
        {

            table.AddCell("Full Name:\r\r" + dr[0].ToString());
            table.AddCell("Contact :\r\r " + dr[1].ToString());
            table.AddCell("Type Of Crime :\r\r " + dr[2].ToString());
            table.AddCell("Location :\r\r " + dr[3].ToString());
            table.AddCell(Image1.Attributes["src"] = MemberReportImage1.aspx?);
            table.AddCell("PoliceID :\r\r " + dr[5].ToString());
            table.AddCell("Police Report Date Time :\r\r " + dr[6].ToString());
            table.AddCell("Police Report :\r\r " + dr[7].ToString());
            table.AddCell("Citizen Report :\r\r" + dr[8].ToString());
            table.AddCell("Admin Official Report :\r\r" + dr[9].ToString());

        }

        dr.Close();
        doc1.Add(table);
        doc1.Close();
        btnPDF.Enabled = false;
    }
}

更新

我设法在下面的链接中 通过 iTextSharp ASP.NET 将二进制图像数据从 SQL Server 检索到 pdf答案的帮助下解决了这个问题

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1 回答 1

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http://www.mikesdotnetting.com/Article/87/iTextSharp-Working-with-images

请看上面的链接。

我假设您将图像文件的二进制数据保存在 sql 数据库中。

如果是，您不需要获取解码图像。您可以使用 Image.FromStream() 加载图像数据。

于 2013-06-07T08:21:41.520 回答