Android Question Solved - Can multiple File.OpenOutput yield 1 file?

anOparator · Sep 1, 2015

display image 1, then image 2, etc from db.

B4X:

Sub Button1_Click
If pos = 61 Then
   pos = 0
   ReadBlob
   prnt2                         '
Else
   pos = pos + 1
   ReadBlob
   prnt2                ' Save to file.
End If
End Sub

And save the OutputStream to file, ending up with all the images on SD Card.

B4X:

Sub prnt2
Dim Cursor3 As Cursor = SQL1.ExecQuery("select image FROM MyTable WHERE name = name")
  Cursor3.Position = pos
  Dim Bmp As Bitmap           '
     If Cursor3.RowCount > pos Then
  Dim binImage() As Byte, Otpt As InputStream
  binImage = Cursor3.GetBlob("Image")
  Otpt.InitializeFromBytesArray(binImage, 0, binImage.Length)
  Bmp.Initialize2(Otpt)
  Otpt.Close
  End If
  Cursor3.Close
     
Dim out As OutputStream = File.OpenOutput(File.DirDefaultExternal, pos & ".png" , True)  

out.WriteBytes(binImage, 0, binImage.Length)
out.Close
End Sub

I tried

B4X:

Dim out As OutputStream = File.OpenOutput(File.DirDefaultExternal, 8 & ".png" , True)

but ended up with only the first file named 8.png.

How would I have each OutputStream overwrite the previous one so that I always have only one file in DirDefaultExternal?
Something like the MS-DOS command prompt:
Dir > 1.png
Many thanks in advance for all tips.

DonManfred · Sep 2, 2015

i would try it like this.

B4X:

Sub prnt2
    Dim Cursor3 As Cursor = SQL1.ExecQuery("select image FROM MyTable WHERE name = name")
    Cursor3.Position = pos
    Dim Bmp As Bitmap           '
    If Cursor3.RowCount > pos Then
        Dim binImage() As Byte, Otpt As InputStream
        binImage = Cursor3.GetBlob("Image")
        Otpt.InitializeFromBytesArray(binImage, 0, binImage.Length)
        Bmp.Initialize2(Otpt)
        Otpt.Close
        Dim out As OutputStream = File.OpenOutput(File.DirDefaultExternal, pos & ".png" , True)
        Bmp.WriteToStream(out, 100, "JPEG") ' write the bitmap to the stream
        out.Close
    End If
    Cursor3.Close
End Sub

anOparator · Sep 2, 2015

DonManfred said:

i would try it like this.

B4X:

Sub prnt2
    Dim Cursor3 As Cursor = SQL1.ExecQuery("select image FROM MyTable WHERE name = name")
    Cursor3.Position = pos
    Dim Bmp As Bitmap           '
    If Cursor3.RowCount > pos Then
        Dim binImage() As Byte, Otpt As InputStream
        binImage = Cursor3.GetBlob("Image")
        Otpt.InitializeFromBytesArray(binImage, 0, binImage.Length)
        Bmp.Initialize2(Otpt)
        Otpt.Close
        Dim out As OutputStream = File.OpenOutput(File.DirDefaultExternal, pos & ".png" , True)
        Bmp.WriteToStream(out, 100, "JPEG") ' write the bitmap to the stream
        out.Close
    End If
    Cursor3.Close
End Sub

Thanks for the Tag reminder, the Sub should end with the starting Tag (Cursor3).
However all the images get written to SD card.

Is there a way to force

B4X:

Dim out As OutputStream = File.OpenOutput(File.DirDefaultExternal, pos & ".png" , True)

to overwrite the previously written file and only have the last seen file on SD card?
Yes

B4X:

Dim out As OutputStream = File.OpenOutput(File.DirDefaultExternal, "Picture" & ".png" , False)

Thanks, you're a genius. I will donate.

DonManfred · Sep 3, 2015

anOparator said:
However all the images get written to SD card.

If you do it right it just will work

Android Question Solved - Can multiple File.OpenOutput yield 1 file?

anOparator

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DonManfred

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anOparator

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DonManfred

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Android Question Solved - Can multiple File.OpenOutput yield 1 file?

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