InvalidCastException When Reading A BLOB Object (PDF File) From An SQL Database?
Nov 3, 2011
I'm having problems with an Invalid Cast Exception when I try and read a PDF from a database as a BLOB. I am able to write the files into the database no problems at all,however, when I try to retrieve them I just get InvalidCastException.Here is the code I'm using:
Protected Sub btnPDF_Click(sender As Object, e As EventArgs) Handles btnPDF.Click
' Request.QueryString["docid"].ToString();
Dim docuid As String = "b39a443d-ccfd-47f4-b333-f12cd94683d6"
[code].....
View 1 Replies
ADVERTISEMENT
May 4, 2011
I'm trying to read a binary file from a FileMaker 11 container field using Filemaker's own ODBC driver. I was able to write files to the database and this works fine. retrieving them manually works fine and the files look OK and are not corupted. However when retreiving them using VB.NET, and if the file size is approx > 5MB, I get the following "uncatchable" error (yes thats right, I cant "Try Catch End Try", it just crashes):
System.AccessViolationException was unhandled
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
[code].....
View 1 Replies
Jan 12, 2011
I just wondering can Itext done the following function before i dive into it.I want to develop a window application, and schedule this application in my server. This application should query the data from (oracle) and with itext help (i hope it help), generate pdf report. Then insert back to oracle as blob.
View 2 Replies
Dec 9, 2009
I need to add a download counter to know how many times my BLOB data is read and displayed from the database (to determine traffic). How and where can I add this counter?
I have a dynamically generated list of links such as <a href="page.aspx?DocID=IDhere">Document filename</a> which direct to a display page.My display page code looks like:
Protected Sub Page_Load
Dim DocID As Integer = Convert.ToInt32(Request.QueryString("DocID"))
Dim connStr As String = conn string here
[code]....
View 1 Replies
Apr 21, 2012
I'm trying to read a BLOB from a SQLite Database.
View 3 Replies
Apr 11, 2009
How do I store BLOB data (e.g. image, document) into the database?
View 1 Replies
Jan 13, 2011
I have just upgraded to Microsoft Visual Basis 2010 Express (Running on Vista and Microsoft Office Excel 2007). The last time I used VB was about 5 years ago and was v5.0 I am trying to do the very simple action of opening a spreadsheet using VB and reading in cell values into two text boxes (I am using an example posted on the web to ensure my approach is correct). The run fails at the point:
[Code]...
View 1 Replies
Sep 29, 2010
I am using Visual Studio 2005, Version 2.0. Coding a windows application with VB.NET.I am trying to use a textbox (txtLogCall) to display matched results in a datagrid. I have added a bindingsource and have the dataset and tableadapter.
I have set the databinding tag of the datagrid to the field that I want to use as a parameter. The textbox is for an Caller's Name, so I have set the datagrid tag to 'EmergencyCallerIdentification' that is in the table.
[Code]...
View 2 Replies
May 7, 2010
Visual Basic 2008 I'm trying to delete a row from an Access database in my DataGridView using a coded delete button. I have an input box asking for a row number to delete. It works fine except if I have anything but an interger, leave the input blank, or hit the cancel, I get :
[Code]...
View 1 Replies
May 13, 2010
ASP.net app inserts Microsoft Windows 2007 .docx file into a row on DB2 OS/390 Blob table. A different VB.net app gets the DB2 OS/390 Blob data. VB.net app kicks off Microsoft Word to open the .docx file but then Microsoft Word pops up a message that the data is corrupted. Word will allow you to fix the data so the file can be viewed but it is extra steps and users complain.I've seen some examples where .docx can be converted to .doc but they only talk about stripping out the text. Some of our .docx have pictures in them.
View 1 Replies
Mar 17, 2009
I am recieving an error when I am trying to write a blob file to MySQL. figure out what I am doing wrong. Here is my code:
[Code]...
View 14 Replies
Apr 25, 2012
below is my piece of code where I click on "Edit button" then retrieve the data from access database so that I edit them on a form.
This is what I get when I click on edit: InvalidCastException was unhandled and highlights the line below The UserID contain Alphanumeric characters.
'check for the selected item in list
If lvUsersList.SelectedItems.Count > 0 Then
If Me.lvUsersList.SelectedItems.Count > 0 Then
[Code].....
View 1 Replies
May 14, 2010
Trying to insert a large audio file into an Oracle 10g database and keep getting this error:
ORA-01460: unimplemented or unreasonable conversion requested
The byte array length of the audio file is 2702577. The procedure works with smaller array lengths, but not the larger ones.
Here is my code:
Dim oracleConnection As New OracleClient.OracleConnection
Dim Cmd As New OracleClient.OracleCommand
Dim oracleDataAdapter As New OracleDataAdapter
oracleConnection.ConnectionString = System.Configuration.ConfigurationManager.AppSettings("MasterConnectionODT")
[Code] .....
View 1 Replies
Aug 29, 2010
I have a mySQL table(IMP_SCANS) holding the file, it's name and size for every document:
scan_1 blob
description varchar
filesize int
doc_no varchar
doc_date date
I managed to insert a file to the table. Now I need to save the file to disk.
So I have the code:
Dim conn As New MySqlConnection
Dim cmd As New MySqlCommand
Dim myData As MySqlDataReader
Dim SQL As String
Dim FileSize As UInt32
Dim fs As FileStream
[CODE]............
I all works fine up to the line: myData.GetBytes(myData.GetOrdinal("scan_1"), 0, rawData, 0, filesize) Where it says "Object reference not set to an instance of an object". I cannot figure out why I receive this error.
View 5 Replies
Oct 2, 2009
I have been trying to create a login page for a while and most of that time I have been searching for info on how to make it read the username, password and any other information off of a database.
I recently gave up and decided to use some code which reads it from a .txt file and this works and therefore I could complete the rest of the page and test it using the .txt file. However, a .txt file is not an ideal place to store the information as it is difficult to look at the text and find what you need to change if you want to upgrade the system to hold more data than before so therefore I came to this site to seek help on making the login page work with a database.
View 3 Replies
Jul 14, 2010
I'm trying to zip a file that is stored on SQL Server as a blob image field and when downloading the zip file it says the file is corrupted.. or the file will open but contains some crazy characters. I've tried WinRAR and 7zip and no luck. I checked out [URL] and tried to kind of combine the browser attachment code and the memorystream/byte array code and no luck.
Here is my code snippet:
Try
BinData = DirectCast(dt.Rows(0)("ImageField"), Byte())
Catch ex As Exception
End Try
Dim blen As Integer = BinData.Length
[Code] .....
View 12 Replies
Feb 15, 2010
I want to read a csv file into an access database , here is my code :
Private Sub load_csv()
Dim ConnectionString As String
ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;" & _
[Code].....
The strange thing is that the file really is there, so what else could go wrong ?
View 1 Replies
Jul 14, 2010
How can in include registry file when compiling my program?
I want to include an .ini to give the users the ability to change the database path for example
[DBConnection]
DATADIRECTORY
p:data
[Code]....
how to program it, or is there a better way than using ini files?
I'm using visual studio 2008.
View 3 Replies
Jan 23, 2009
i have maid a simple login system in vb.net here is my current code
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If TextBox1.Text = "http://mywebsite.com/usernames.txt" Then
Form2.Show()
Me.Hide()
[code]....
View 6 Replies
Apr 11, 2011
I have determined thanks to the last q & a that there is something wrong with my "save to db" code as well as my "retrieve to picture" code. Even If I manually save the pic in the db it stil wont retreive. This is code i patched together from 3 or 4 examples around the net.
Dim filename As String = txtName.Text + ".jpg"
Dim FileSize As UInt32
Dim ImageStream As System.IO.MemoryStream[code]......
View 2 Replies
Sep 14, 2011
I'm trying to get the price out (90.0) of this xml document but get it to work, i've tried using the xmlTextReader and the ReadElementString function but I guess I need to get the attribute. I then looked at using the GetAttribute function.
[Code]...
View 1 Replies
Mar 11, 2010
I have a program that will download files from a company website given a list of links. The site requires authentication, and I do have code that will set the authentication cookie in the request header. I get the authentication cookie from a Perl script we have. What I would love to do is have my vb .net program get the authentication cookie based on my username and password. The perl script goes to the following link:
[URL]
The it reads the cookie out of the response. Here is the code I have, but my cookie count always comes back at zero. :(
Dim cookieJar As New Net.CookieContainer()
Dim cookie As New Net.Cookie
Dim req As Net.HttpWebRequest
[Code].....
View 1 Replies
Mar 7, 2012
I develop a simple application usiing VB.NET, VisualStudio 2008, that read input from a serial port
(from another device). I use the class SerialPort.
Using HyperTerminal I can see the input , it's fine. looks like :
S0P,A,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0 S0P,A,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
[Code]...
View 5 Replies
May 4, 2009
I'm trying to pass a business object from one WinForm to another WinForm for modification, and then repopulate the text boxes, etc. on the first form with the updated values.However, it seems that the object values set in the second form are not "sticking" when the code control returns to the first form.Is there a way to view the memory location of an object in VB.NET? I want to first make sure that the object variable on the second form is pointing to the same memory address as the object on the first form. Then I can take it from there.
In a separate VB project, I passed a simple object to a second form, modified the values, and re-displayed the object's values on the first form. It worked fine. In my real app, I'm passing an object that is a property of another object, which may be why it isn't working.SOLUTION: The problem was that I was using a DeepCopy() function that I found to simplify copying the properties of one object to another. Removing that function and manually setting the values to the passed object on the second form (ex. obj.property1
View 1 Replies
May 23, 2012
I have published xml document through web service like this
<WebMethod()> _
Public Function HelloWorld() As XmlDocument
Dim xmlDoc As New XmlDocument
[code]....
View 1 Replies
May 3, 2011
I was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"
View 2 Replies
Nov 11, 2010
I am creating some reports using object datasources.in my software the user can create a list of products specifying a code, the product name, the price and the vat rate (this last two attributes will be used as suggestions when the user will place the product inside an order).When a user creates an order he can place products within it by specifying for each product the quantity and he can also override the suggested price and the vat rate.So basically i have two models to represent the products:
ProductModel (used to define product name, product code and the default suggestion for price and vat rate)OrderProductModel (used to place products within an order, specify the quantity and override the default product suggestion for price and vat number)
ProductModel:
id
code
name
[code]...
(suppose orderProduct is an instance of OrderProductModel)Now the question is "how to define the report rule to access to code and name?"...I am using visual studio 2010 and by reading here:[URL]they says that the syntax: =Fields!Object.Value.attribute no longer works...
View 2 Replies
May 10, 2010
Is this class normally slow or maybe there is something in my process making it slow.I have to import 170,000 rows of data from a fixed length text file into a SQL table. It takes about 2 minutes in a DTS package on SQL server 2000. But we are migrating to a SQL 2008 server and since this code has several manual steps and does not manipulate the data I thought it would be easier to use the TextFieldParser object to handle reading in the data.
Here is the code:
CODE:
View 15 Replies
Jan 14, 2011
what is wrong with my code it is supposed to output all tables in my sql database but it is giving me an error saying object reff not set to instance of object
ListBox1.Items.Add(CType(GetTables().ToString, String
Public Shared Function GetTables() As String()
Dim kon As SqlConnection[code].....
View 1 Replies
Jan 2, 2010
I am working on a project in VB 2008 and need it to do this:Read first line from text file (using Openfile)Enter line into textbox on formDo some other codeThen Read second linefrom text fileEnter line into same text boxand loop until we have gone through text fileI am not sure how to read line by line from text file then enter it in textbox. I can open the Openfile and get the filename and everything, but I just am not sure how to read from it or enter that line into the textbox.Here is what I have, its not much but its a start:
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim FileReader As StreamReader
[code]....
View 4 Replies
