Android Question blob on Imageview? - Solved

anOparator · Aug 6, 2015

I used SQLite to make database = test2,
table = stuff:
There are 3 records for [_id] Numeric, [name] Text, [image] Blob

Am wanting to understand how to alternate image1, 2, and 3 on an Imageview (just noticed there is none in the SQL Blob tutorial) using:

B4X:

   Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))

             OR
  Buffer = Cursor1.GetBlob2(0)  'ERROR: CursorIndexOutOfBoundsException: Index -1 requested, with a size of 0

After 2 weeks and a bunch of errors I still need help with the syntax.
All tips appreciated.

B4A v4.3
.NET Framework 4.5

Mahares · Aug 6, 2015

This should accomplish it for you:

B4X:

Dim imageview1 As ImageView
    Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))
    Cursor1.Position = 0
    Dim Buffer() As Byte 
    Buffer = Cursor1.GetBlob("image")
    Dim InputStream1 As InputStream
    InputStream1.InitializeFromBytesArray(Buffer, 0, Buffer.Length)
    Dim Bitmap1 As Bitmap
    Bitmap1.Initialize2(InputStream1)
    InputStream1.Close
    imageview1.SetBackgroundImage(Bitmap1)

anOparator · Aug 6, 2015

Mahares said:

This should accomplish it for you:

B4X:

Dim imageview1 As ImageView 
    Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))
    Cursor1.Position = 0
    Dim Buffer() As Byte
    Buffer = Cursor1.GetBlob("image")
    Dim InputStream1 As InputStream
    InputStream1.InitializeFromBytesArray(Buffer, 0, Buffer.Length)
    Dim Bitmap1 As Bitmap
    Bitmap1.Initialize2(InputStream1)
    InputStream1.Close
    imageview1.SetBackgroundImage(Bitmap1)

Thanks for the pointers, compiles better. I put the underlined text in and get my msgbox, will re-create test2.db.

Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))
Cursor1.Position = 0
If Cursor1.RowCount = 0 Then ' Initialize Cursor error.
Msgbox("any Rows", "questiion")
End If
Dim Buffer() As Byte

anOparator · Aug 7, 2015

This forum is great:
I removed the InsertBlob and CreateTables entries,
Checked my SQLite db with DB Browser for SQLite,
found
<a href="https://www.b4x.com/android/forum/t...-row-from-sqlite-solved-thanks.44814/#content">A great template</a>, for 'Select Row/Column',
I think I'm a happy camper.

anOparator · Aug 11, 2015

Hello again, please tell me if these Debug pics are telling me that Cursor1 and Imageview1 are not initialized, or is the problem in the Sub?

B4X:

Sub ReadBlob
   Private ImageView1 As ImageView
   Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))
    Cursor1.Position = 0
   Dim Buffer() As Byte
  Buffer = Cursor1.GetBlob("image")    ' Error = CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0 
  Dim InputStream1 As InputStream
  InputStream1.InitializeFromBytesArray(Buffer, 2, Buffer.Length)
  Dim Bitmap1 As Bitmap
  Bitmap1.Initialize2(InputStream1)
  InputStream1.Close
  ImageView1.SetBackgroundImage(Bitmap1)
    ImageView1.Color=Colors.Cyan       ' Color does NOT appear
  
'    If Cursor1.RowCount < 5 Then     ' Msgbox does NOT appear with 3 images in the db.
    If Cursor1.RowCount > 0 Then       ' Msgbox does NOT appear with 3 images in the db.
   Msgbox("any Rows", "what")
End If
End Sub

thanks in advance

B4A v4.3
.NET Framework 4.5
Java x86
C:\Android

DonManfred · Aug 11, 2015

anOparator said:
Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))

will result in something like

SELECT image FROM stuff WHERE name = "name"

Does this find a record in your table?

anOparator · Aug 11, 2015

DonManfred said:
will result in something like

Does this find a record in your table?

Thanks but Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = name", Array As String("name")) gives error:
android.database.sqlite.SQLiteBindOrColumnIndexOutOfRangeException: bind or column index out of range: handle 0x1625e88

anOparator · Aug 12, 2015

DonManfred said:
will result in something like

Does this find a record in your table?

Thanks so much for the pointer. SQL1.ExecQuery without extra argument enabled sending db image using Button1_Click to Imageview.

Will update post in a few days

derez · Aug 12, 2015

This

Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = name", Array As String("name"))

should be:

B4X:

Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))

anOparator · Aug 12, 2015

derez said:
This
should be:

B4X:

Cursor1 = SQL1.ExecQuery2("SELECT image FROM stuff WHERE name = ?", Array As String("name"))

Thanks I got it working with,

B4X:

Cursor1 = SQL1.ExecQuery("SELECT image FROM stuff WHERE name = name").

Didn't need the 'Array As String("name"))' argument because that is the Value of the smiley_face.jpg in the sample.

Now I have

B4X:

Cursor2 = SQL1.ExecQuery("SELECT name FROM stuff WHERE name = name").

in 'Sub ReadBlob' to place the records text on Label1 at the same time the image goes on Imageview1.

And lastly, Button2_Click fires 'Sub ReadBlob' and does Cursor1.Position=Cursor1.Position + 1 to show the next recordset, etc.
Maybe tomorrow Button1 gets replaced by a timer.
Kudos for the reading material everyone.

Android Question blob on Imageview? - Solved

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