Yet another save question....

[vcvc]

Sorry.... this is another how to save question.

I have looked in every forum for a solution, and I think I have tried every solution with no success.

I guess I'm a complete idiot or old...same thing I guess.

I'm attempting to perform some simple image manipulation using a simple form with simple controls and 2 images. Image on left is unmodified, image on right is the modified "preview". any changes to the control (slider etc) invalidate the form calling onpaint. So far so good - nice simple UI , preview works nice .......... until I try to save. Then I get the same old "my changes are not being saved".

Well...my changes are not being saved.

No, I am not using picture boxes , and yes I am creating a bitmap and writing to that as opposed to the control.

No...I am not drawing silly little lines or arcs etc on the picture, and YES I have looked at every bit of GDI documentation I could find (most of which is junk!).

Please point out my stupid blunder:

Private Sub Frm_GDI_SUX_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
       Dim ArrayPts As Single()() = {New Single() {1, 0, 0, 0, 0}, _
         New Single() {0, 1, 0, 0, 0}, _
         New Single() {0, 0, 1, 0, 0}, _
         New Single() {0, 0, 0, tpVal, 0}, _
         New Single() {0, 0, 0, 0, 1}}
       Dim colorMat As New ColorMatrix(ArrayPts)
       Dim Attrib As New ImageAttributes()
       Attrib.SetColorMatrix(colorMat, ColorMatrixFlag.Default, ColorAdjustType.Bitmap)
       Dim ModImg As Image = Image.FromFile(GetFileName(Active_Ctl))
       Dim bmp As New Bitmap(ModImg)
       e.Graphics.FromImage(bmp)
       e.Graphics.DrawImage(bmp, New Rectangle(265, 10, 200, 200), 0, 0, bmp.Width, bmp.Height, GraphicsUnit.Pixel, Attrib)
       bmp.Save("c:\GDI_sux.bmp")
End Sub

 

Please forgive my ignorance as I normally write code that does something bigger than playing with silly little pictures or worse..games.

My wife has requested a small app to manipulate some images...I wisely replied with a "Yes dear"....here we are....

Help me..... the sooner I can get this thing behind me the sonner I can get out of this silly GDI thing,.

Edited November 16, 2003 by Volte

[Volte]

Graphics.FromImage() returns a Graphics object. You need to change the last few lines of code to this:

Dim bmp As New Bitmap(ModImg)
Dim g As Graphics = Graphics.FromImage(bmp)
g.DrawImage(bmp, New Rectangle(265, 10, 200, 200), 0, 0, bmp.Width, bmp.Height, GraphicsUnit.Pixel, Attrib)
bmp.Save("c:\blah.bmp")

[vcvc]

Thanks...but been there done that (but tried it again anyway)

The graphics do not draw, and the save throws "Object reference not set to an instance of an object"

 

I understand what you are saying and have tried it (and various combinations) countless times.

If I use e.graphics, everything runs, but does not save.

As soon as I create a different graphics object..it blows up.

Makes no sense to me.....

 

Thanks for trying

[Volte]

Can you paste exactly what code gives you the Object Reference Not Set error?

[vcvc]

The object refence error was my bad...had a stray on my OK button.

However the following still shows no image and saves the original:

 

Private Sub FrmImgModify_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint

'Dim curImage As Image = Image.FromFile(GetFileName(Active_Ctl))

'e.Graphics.DrawImage(curImage, 10, 10, 200, 200)

Dim ArrayPts As Single()() = {New Single() {1, 0, 0, 0, 0}, New Single() {0, 1, 0, 0, 0}, New Single() {0, 0, 1, 0, 0}, New Single() {0, 0, 0, tpVal, 0}, New Single() {0, 0, 0, 0, 1}}

Dim colorMat As New ColorMatrix(ArrayPts)

Dim Attrib As New ImageAttributes()

Attrib.SetColorMatrix(colorMat, ColorMatrixFlag.Default, ColorAdjustType.Bitmap)

Dim ModImg As Image = Image.FromFile(GetFileName(Active_Ctl))

Dim bmp As New Bitmap(ModImg)

Dim g As Graphics = Graphics.FromImage(bmp)

g.DrawImage(bmp, New Rectangle(265, 10, 200, 200), 0, 0, bmp.Width, bmp.Height, GraphicsUnit.Pixel, Attrib)

bmp.Save("c:\blah.bmp")

End Sub

 

Thanks