如何在C＃中将标记的src设置为字节数组中的pdf内容

Question

In my web application, I am saving the uploaded pdf as Blob data in my oracle db.

Now while fetching the same blob data, I am getting it as byte array as below:-

public static byte[] OpenAttachment(string strAttachNo, bool isOverloaded)
    {
        OracleConnection objConn = OracleHelper.GetConnection("myDB");
        OracleDataReader dtApplReader = null;
        string strProc = "mySpName";
        OracleParameter[] oraParam = new OracleParameter[2];
        oraParam[0] = new OracleParameter("p_attach_no", OracleType.Number);
        oraParam[0].Direction = ParameterDirection.Input;
        oraParam[0].Value = long.Parse(strAttachNo);
        oraParam[1] = new OracleParameter("p_curresult", OracleType.Cursor);
        oraParam[1].Direction = ParameterDirection.Output;
        objConn.Open();
        dtApplReader = OracleHelper.ExecuteReader(objConn, CommandType.StoredProcedure, strProc, oraParam);
        while (dtApplReader.Read())
        {
            byte[] val = (byte[])dtApplReader["ATTACHMENT"];

            return val;
        }

In my UIPage.aspx.cs, I am converting this byte array to base64 string as below.

 string base64String = Convert.ToBase64String(bytes, 0, bytes.Length);
 var pdfUrl  = "data:application/pdf;base64," + base64String;
 pdfPreview.Attributes.Add("src", base64String);

UI Control

<embed src="#" visible="false" width="500" height="375" runat="server" type='application/pdf' id="pdfPreview"  />

but somehow that pdf is NOT rendering, while inspecting in Chrome dev tools,

How do I set this base64 string to proper pdf content??

Answer 1

Instead of adding base64String as src attribute, You should use pdfUrl as src attribute.

string base64String = Convert.ToBase64String(bytes, 0, bytes.Length);
var pdfUrl  = "data:application/pdf;base64," + base64String;
pdfPreview.Attributes.Add("src", pdfUrl);

Hope this helps!