I want to display picture from access and show that on a form in vb.net
I have this for display information:
info.TextBox5.Text = DataGridView1.SelectedRows(0).Cells(5).Value
Now I tried something like this for pictures:
info.PictureBox1.Image = DataGridView1.SelectedRows(0).Cells(6).Value
But I got an error:
Can not associate the type of Object ' System.Byte []' to type '
System.Drawing.Image ' .
Can you help me?
dim str as string =DataGridView1.SelectedRows(0).Cells(5).Value
if str <> string.empty then
info.TextBox5.Text = str
end if
Use this:
Using ms As New MemoryStream(CType(DataGridView1.SelectedRows(0).Cells(6).Value, Byte()))
info.PictureBox1.Image = New Bitmap(ms)
End Using
Since you cannot simply assign a Byte() to an Image, you need to first create a Bitmap out of the data.
So what the above code does is:
Creates a new MemoryStream with the Byte() returned by DataGridView1.SelectedRows(0).Cells(6).Value.
Initializes a new Bitmap with the data in that stream, so that you can assign it to the Image property of your PictureBox.
Related
Receiving below error on deserializing json to dataset.
Unexpected JSON token when reading DataTable. Expected StartArray, got Integer. Path 'id', line 1, position 9
Json Retrieved : {"id":130,"type":"general","setup":"test?","punchline":"test."}
My Code
Dim wc As New WebClient
Try
Dim res As String
For i = 0 To 5
res = wc.DownloadString("https://official-joke-api.appspot.com/random_joke")
Dim jObject = JsonConvert.DeserializeObject(res)
Dim ds As New DataSet
ds = JsonConvert.DeserializeObject(Of DataSet)(res)
MsgBox(ds.Tables.Count)
Next
Catch ex As Exception
MsgBox(ex)
End Try
As user Akshay Gaonkar commented, you can give Newtonsoft.Json a class, named, say, Joke, to deserialise with. You can get around the mismatch of uppercase/lowercase initial letter naming conventions by decorating the properties with <JsonProperty("nameInTheJson")>.
Instead of deserializing the data into a datatable inside a dataset, you could keep it simple and create a List(Of Joke).
This is for a console application:
Imports System.Net
Imports Newtonsoft.Json
Module Program
Class Joke
<JsonProperty("id")>
Property Id As Integer
<JsonProperty("type")>
Property Type As String
<JsonProperty("setup")>
Property Setup As String
<JsonProperty("punchline")>
Property Punchline As String
End Class
Sub Main(args As String())
Dim jokes As New List(Of Joke)
Using wc As New WebClient()
For i = 1 To 5
Dim jokeInfo = wc.DownloadString("https://official-joke-api.appspot.com/random_joke")
jokes.Add(JsonConvert.DeserializeObject(Of Joke)(jokeInfo))
Next
End Using
' Alternative which fetches ten jokes in one go - note the use of (Of List(Of Joke))
'Using wc As New WebClient()
' Dim jokeInfo = wc.DownloadString("https://official-joke-api.appspot.com/jokes/ten")
' jokes = JsonConvert.DeserializeObject(Of List(Of Joke))(jokeInfo)
'End Using
For Each jk In jokes
Console.WriteLine($"{jk.Setup}{vbCrLf}{jk.Punchline}{vbCrLf}")
Next
End Sub
End Module
The Using statement is needed because a WebClient should be disposed of after use to clear up system resources. (You could use the equivalent Try...Finally with wc.Dispose() instead.)
The JSON you showed is invalid. Datatable is expecting array of Object , so the JSON should look like below :
[{"id":130,"type":"general","setup":"test?","punchline":"test."}]
I want to read 2D matrixcode from an image that I captured using camera and display it on a picturebox. The image will be saved from picturebox and then it will read the value of 2D matrixcode from the image.
I managed to read it one time. However, the second time I click the button to read it, it appeared this error. ": A generic error occurred in GDI+."
I want it able to capture it multiple time for each time I click.
Below are my attached code :
Dim filepath As String = Environment.CurrentDirectory
Dim current2 As Bitmap = CType(PictureBoxFilter.Image, Bitmap)
Dim fileName2 As String = System.IO.Path.Combine(filepath, "test.png")
current2.Save(fileName2)
Dim decoder As DmtxImageDecoder = New DmtxImageDecoder()
Dim codes As List(Of String) = decoder.DecodeImage(CType(Bitmap.FromFile(System.IO.Path.Combine(filepath, "test.png")), Bitmap), 1, New TimeSpan(0, 0, 3))
For Each code As String In codes
If code <> "" Then
Label1.Text = code
Else
Label1.Text = ""
End If
Next
codes.Clear()
current2.Dispose()
When I retrieve an object from my DB, I try to do this:
Dim pictureBytes As New MemoryStream(imagen.JugFir)
pictureBox2.Image = Image.FromStream(pictureBytes)
But I get an error:
'imagen.JugFir' is an Object and Image.FromStream() requires a Byte[].
How i can convert Object to Byte[] ?
Or is there any other way to load the picture?
I have an Access Database linked with a VB project through a data source. In the database on one of the tables, I have an OLE Object field. I have saved pictures in .BMP format and .JPG format in this field. The problem I am encountering is loading this image into my application. This is what I would like to be able to do:
ButtonMeal1.BackgroundImage = IPOSDBDataSet.Meals.Rows(0).Item(5)
Where Item(5) is the column of the row where the image is stored.
Is there another way of doing this. Do I have to load the picture into the program by storing it as a variable, and then using that to change the background image of the button. There are no clear answers on the internet regarding my issue. Please help!
EDIT 1:
After doing some more research, I found some code and adjusted it to try fix my problem.
Dim ImageByteArray As Byte() = CType(IPOSDBDataSet.Meals.Rows(0).Item(5), Byte())
Dim ImageMemoryStream As MemoryStream = New IO.MemoryStream(ImageByteArray)
Dim MyImage As Image = Drawing.Image.FromStream(ImageMemoryStream)
PictureBox1.Image = MyImage
However, I receive the error "Parameter is Not Valid" with the 3rd line of the code. Would anyone be able to tell me how I could adjust my code to fix this issue, or tell me if I am doing something completely wrong?
EDIT 2:
I keep on changing the code around, but the error is always "Parameter is not valid.". What parameter is not valid?
EDIT 3:
No matter what I change it to, the error still persists. What is this parameter that is causing all my issues?
Dim ImageByteArray As Byte() = CType(IPOSDBDataSet.Meals.Rows(0).Item(5), Byte())
Dim ImageMemoryStream As MemoryStream = New IO.MemoryStream(ImageByteArray)
Dim ImageStream As Stream = ImageMemoryStream
Dim MyImage As Image = Drawing.Image.FromStream(ImageStream)
PictureBox1.Image = MyImage
EDIT 4:
Can anyone please help? I really need to be able to implement this into my program. Is there any other possible way of storing images in an access database, and importing them into my vb.net program?
Credit goes to TnTinMan from CodeProject for the answer. Hopefully this helps someone else:
Dim ImageByteArray As Byte() = CType(DataSet.Table.Rows(RowNo).Item(ItemNo), Byte())
Dim ImageMemoryStream As MemoryStream = New IO.MemoryStream(GetImageBytesFromOLEField(ImageByteArray))
Dim MyImage As Image = Drawing.Image.FromStream(ImageMemoryStream)
Friend Shared Function GetImageBytesFromOLEField(ByVal oleFieldBytes() As Byte) As Byte()
Dim BITMAP_ID_BLOCK As String = "BM"
Dim JPG_ID_BLOCK As String = ChrW(&HFF).ToString() & ChrW(&HD8).ToString() & ChrW(&HFF).ToString()
Dim PNG_ID_BLOCK As String = ChrW(&H89).ToString() & "PNG" & vbCrLf & ChrW(&H1A).ToString() & vbLf
Dim GIF_ID_BLOCK As String = "GIF8"
Dim TIFF_ID_BLOCK As String = "II*" & ChrW(&H0).ToString()
Dim imageBytes() As Byte
' Get a UTF7 Encoded string version
Dim u7 As System.Text.Encoding = System.Text.Encoding.UTF7
Dim strTemp As String = u7.GetString(oleFieldBytes)
Dim st2 As String = System.Text.Encoding.UTF8.GetString(oleFieldBytes)
' Get the first 300 characters from the string
Dim strVTemp As String = strTemp.Substring(0, 300)
' Search for the block
Dim iPos As Integer = -1
If strVTemp.IndexOf(BITMAP_ID_BLOCK) <> -1 Then
iPos = strVTemp.IndexOf(BITMAP_ID_BLOCK)
ElseIf strVTemp.IndexOf(JPG_ID_BLOCK) <> -1 Then
iPos = strVTemp.IndexOf(JPG_ID_BLOCK)
ElseIf strVTemp.IndexOf(PNG_ID_BLOCK) <> -1 Then
iPos = strVTemp.IndexOf(PNG_ID_BLOCK)
ElseIf strVTemp.IndexOf(GIF_ID_BLOCK) <> -1 Then
iPos = strVTemp.IndexOf(GIF_ID_BLOCK)
ElseIf strVTemp.IndexOf(TIFF_ID_BLOCK) <> -1 Then
iPos = strVTemp.IndexOf(TIFF_ID_BLOCK)
Else
Throw New Exception("Unable to determine header size for the OLE Object")
End If
' From the position above get the new image
If iPos = -1 Then
Throw New Exception("Unable to determine header size for the OLE Object")
End If
imageBytes = New Byte(CInt(oleFieldBytes.LongLength - iPos - 1)) {}
Array.ConstrainedCopy(oleFieldBytes, iPos, imageBytes, 0, oleFieldBytes.Length - iPos)
Return imageBytes
End Function
There isn't really such a thing as an 'image' stored in an Access table, only a binary stream. Therefore, the left hand side of your expression doesn't know that the right hand side is providing an image. You would have to stream the binary stream into a stream in VB.NET, then use System.Graphics methods to make it into a BMP or PNG or whatever. You could assign that object to the button.
still show error: index and length must refer to a location within the string.Parameter name: len
I want to read Stream that i get from XtrapivotGrid of DevExpress. I can save it in the computer but what i want is to save it in one of my table in my dataset called dataset1.
For now i have that code who permit to save it the directory Temp:.
Using FS As New IO.FileStream("D:\Temp\qqc.layout", IO.FileMode.Create)
PivotGridControl1.SaveLayoutToStream(FS)
End Using
Dim read As New System.IO.FileStream("D:\Temp\qqc.layout", IO.FileMode.Open, IO.FileAccess.Read)
DataSet1.LayoutMainRapport.ReadXml(read)
DataSet1.AcceptChanges()
read.Close()
The table LayoutMainRapport have 3 columns:
ID(Int)
Name(nvarchar(50))
Content(xml).
The output from the stream is xml.
thanks in advance!
I believe you should convert your saved layout into string and then save this string to database (and of course you can load this layout back from the database string value):
Private Function SaveLayoutToString(ByVal dxControl As DevExpressControl) As String
Using ms As MemoryStream = New MemoryStream()
dxControl.SaveLayoutToStream(ms)
Return Convert.ToBase64String(ms.ToArray())
End Using
End Function
Private Sub RestoreLayoutFromString(ByVal dxControl As DevExpressControl, ByVal layout As String)
If String.IsNullOrEmpty(layout) Then
Return
End If
Using ms As MemoryStream = New MemoryStream(Convert.FromBase64String(layout))
dxControl.RestoreLayoutFromStream(ms)
End Using
End Sub
Here DevExpressControl dxControl is the DevExpress control which supports saving and loading layout (XtraPivotGrid, XtraGrid, XtraLayoutControl etc.)
I simply had to save a name for the xml and after save it into my dataset.
Dim saveDialog As SaveLayout = New SaveLayout
If saveDialog.ShowDialog() = Windows.Forms.DialogResult.OK Then
Dim read As New IO.MemoryStream
PivotGridControl1.SaveLayoutToStream(read)
read.Position = 0
Dim lecteur As New IO.StreamReader(read)
Dim ligne As DataRow = DataSet1.LayoutMainRapport.NewRow()
ligne("Nom") = saveDialog.txtNom.Text
ligne("Contenu") = lecteur.ReadToEnd()
DataSet1.LayoutMainRapport.Rows.Add(ligne)
LayoutMainRapportTableAdapter.Update(DataSet1)
End If