You find this example project in your Plugins Download as a Xojo project file within the examples folder: /Images/LargePicture/PNG Load and Save
Class Window1 Inherits Window
Control Canvas1 Inherits Canvas
ControlInstance Canvas1 Inherits Canvas
End Control
Control PushButton2 Inherits PushButton
ControlInstance PushButton2 Inherits PushButton
EventHandler Sub Action()
dim p as Picture
p=LogoMBS(500)
current=new PictureMBS(p)
run
End EventHandler
End Control
Control PushButton3 Inherits PushButton
ControlInstance PushButton3 Inherits PushButton
EventHandler Sub Action()
dim p as Picture
dim q as PictureMBS
p=LogoMBS(500)
q=new PictureMBS(p)
current=new PictureMBS(p.Width, p.Height, picturembs.ImageFormatG)
call Current.CopyPixels(q)
run
End EventHandler
End Control
Control PushButton1 Inherits PushButton
ControlInstance PushButton1 Inherits PushButton
EventHandler Sub Action()
SavePNG
End EventHandler
End Control
Control PushButton5 Inherits PushButton
ControlInstance PushButton5 Inherits PushButton
EventHandler Sub Action()
OpenPNG
End EventHandler
End Control
Control PushButton6 Inherits PushButton
ControlInstance PushButton6 Inherits PushButton
EventHandler Sub Action()
Current=nil
run
End EventHandler
End Control
Sub OpenPNG()
dim f as FolderItem
f=GetopenFolderItem(FileTypes.Png)
if f<>Nil then
Current=nil
dim p as new PNGReaderMBS
if p.OpenFile(f) then
if p.ApplyOptions(0) then
Current=new PictureMBS(p.Width,p.Height,PictureMBS.ImageFormatRGB)
dim i,c as integer
c=p.Height-1
for i=0 to c
Current.RowInFormat(i, PictureMBS.ImageFormatRGBA)=p.ReadRow()
next
end if
end if
run
end if
End Sub
Protected Sub SavePNG()
dim f as FolderItem
f=GetsaveFolderItem(FileTypes.Png,"test.png")
if f<>Nil then
const PNG_COLOR_MASK_PALETTE = 1
const PNG_COLOR_MASK_COLOR = 2
const PNG_COLOR_MASK_ALPHA = 4
dim p as new PNGWriterMBS
p.Width=Current.Width
p.Height=Current.Height
p.Type=PNG_COLOR_MASK_COLOR
p.bpc=3
p.Rowbytes=p.Width*p.bpc
if p.OpenWriteDestination(f) then
if p.SetHeader(false, -1) then
if p.SetGamma(0) then
if p.WriteInfo then
dim i,c as integer
c=p.Height-1
for i=0 to c
p.WriteRow current.RowInFormat(i, Current.ImageFormatRGB)
next
if p.WriteEnd then
MsgBox "OK"
end if
end if
end if
end if
end if
end if
End Sub
Protected Sub run()
if Current=nil then
canvas1.Backdrop=nil
else
Canvas1.Backdrop=current.CopyPicture
end if
End Sub
Property Protected current As PictureMBS
End Class
MenuBar Menu
MenuItem UntitledMenu3 = ""
MenuItem UntitledMenu2 = "File"
MenuItem FileQuit = "Quit"
MenuItem UntitledMenu0 = "Edit"
MenuItem EditUndo = "Undo"
MenuItem UntitledMenu1 = "-"
MenuItem EditCut = "Cut"
MenuItem EditCopy = "Copy"
MenuItem EditPaste = "Paste"
MenuItem EditClear = "Clear"
End MenuBar
Class App Inherits Application
End Class