[RESOLVED] Screenshot-Help me

I want to get the whole screen in image control and then save it to my folder.
Every thing is working fine except the image saved in the folder. Is there any problem in the following code? I also want that the image saved should be overwritten.

vb Code:

Private Sub Command1_Click()
Timer1.Enabled = True
Me.WindowState = vbMinimized
End Sub
 
Private Sub Timer1_Timer()
On Error GoTo errhandler
Label1.Caption = Val(Label1.Caption) + 1
For i = 1 To 10
    Clipboard.Clear
    keybd_event vbKeySnapshot, 0, 0, 0
    DoEvents
        Set Image1.Picture = Clipboard.GetData(vbCFBitmap)
        SavePicture Image1.Picture, "C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp"
    
     Next i
errhandler:
    MsgBox " completed"
    Timer1.Enabled = False
End Sub

I'm not sure you can do it this way. In case it may help I have attached a screen capture project I made some time ago.

By the way, there's a mistake in the ini file:

Must be:
;Default data directory
Dir=C:

rather than
;Default data directory
Dir=C:\

i.e., the backslash is automatically appended by the code.

Ur project is ok. But i want a program which should save no. of images which are specfied in the textbox and should use timer to save image at particular interval and it should also overwrite it without any error.

It shoudn't be to difficult to modify the project so as to have the program minimize the window state and, using a timer, set the code to capture the screen as many times as needed. To be sure, it's going to require a bit of work, of course.

Ya. Because i will have to go through the whole code and i have just few months exp. in vb its bit diff. for me. can u modify my above code so that i can save it to a folder with interval and the files should also be overwritten

Sorry, don't have much time now, but I can have a go at it maybe tomorrow in case no one provides any more suitable code. But I don't think you have to understand much of the code, just place the "shooting" code in the timer event to start with. See what's going on in the "Crop/Capture" button's click event handler. Thereafter modify as necessary, i.e., try to deal with all the errors that will pop up.

To overwrite the files

Code:

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If Dir("C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp") > vbNullString Then Kill "C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp"
SavePicture Image1.Picture, "C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp"

---

Ok. I have got the code.its working fine except it generates error sometimes.The error is "Can't open clipboard" in the line "Set Image1.Picture = Clipboard.GetData(vbCFBitmap)". The code is:

vb Code:

Private Sub Timer1_Timer()
i = i + 1
Label1.Caption = Val(Label1.Caption) + 1
    Clipboard.Clear
    keybd_event vbKeySnapshot, 0, 0, 0
    DoEvents
   Set Image1.Picture = Clipboard.GetData(vbCFBitmap)
        SavePicture Image1.Picture, "C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp"
    Image1.Picture = Nothing
    If i = 10 Then
    Timer1.Enabled = False
    End If
End Sub

I typed "On error resume next".Now its working.But i m not satisfied. i dont want to get that error.Help!

When am i clicking on another window then the error is displaying otherwise when i am just kepping my pc idle then no error is dispalyed. Should i use api function other than timer?

Hi vivek ...
Is it must to use this code to capture window. or you can accept a different code to do the same jop.

Quote:

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Is it must to use this code to capture window. or you can accept a different code to do the same jop.

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This is for what i am asking for? Is there any other way i could do or by making some modifications in my code?

I think it's better to use more advanced API that gives you the ability to capture window. and to get such a code just search the forum for a Capture word .
or get this direct link to ready project made by Moeur member
http://www.vbforums.com/attachment.p...8&d=1123272285

Hey! I want to capture images at intervals and save them in a folder. i have done it. but the only prob is the error.

can you explain what error ...?

Quote:

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Originally Posted by vivek_master146

Hey! I want to capture images at intervals and save them in a folder. i have done it..

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Does that mean it actually worked in some cases?

Hi krtxmrtz ...
It works if you used the right code.!!!

What is keybd_event?

it's an API function to send buttons press event for keyboard
Private Declare Sub keybd_event Lib "user32.dll" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long)

Quote:

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Originally Posted by ashraf fawzy

it's an API function to send buttons press event for keyboard
Private Declare Sub keybd_event Lib "user32.dll" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long)

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I see.
All I can say is I've found this site http://www.cgi-interactive-uk.com/sc..._creation.html with code very similar to Vivek_Master146's, only there is a slight difference: rather than

Set Image1.Picture = Clipboard.GetData(vbCFBitmap)

they have this other statement,

ScreenCapture.Picture = Clipboard.GetData(vbCFBitmap)

i.e., without the "Set" command. I wonder if that could make a difference such as to cause the error. On the other hand, the code on that site is using a picturebox. I wonder if Image1 in Vivek_Master146's code is an Image control or a Picturebox.

It is a image control

I think if you like , you should use the the link I provided above , it gives you more abilities to capture windows or just part of it.

vivek_master, i don't want to have you change your whole way of thinking, but the only useful function i can think of for this is you have two computers any you are monitoring the snapshot from another computer. If this is why you are doing this, windows has built-in tools for this.

I am attaching the project. The error is not displaying if the project is in focus and when i m mizimizing the project then the error is displaying.Help!

I just want to keep a check on the activities of the cpomputer by capturing screenshot at intervals and saving it to a folder?

Quote:

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Originally Posted by Lord Orwell

vivek_master, i don't want to have you change your whole way of thinking, but the only useful function i can think of for this is you have two computers any you are monitoring the snapshot from another computer. If this is why you are doing this, windows has built-in tools for this.

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Try to add this without any modification :and let me know :

Private Sub Timer1_Timer()
keybd_event vbKeySnapshot, 0, 0, 0
Set Image1.Picture = Clipboard.GetData(vbCFBitmap)
SavePicture Image1.Picture, "C:\image1.bmp"
End Sub

Quote:

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Originally Posted by ashraf fawzy

Try to add this without any modification :and let me know :

Private Sub Timer1_Timer()
keybd_event vbKeySnapshot, 0, 0, 0
Set Image1.Picture = Clipboard.GetData(vbCFBitmap)
SavePicture Image1.Picture, "C:\image1.bmp"
End Sub

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Ur code will generate error as the name image1.bmp is same. and if u write a code to overwrite it then also it will save 1 image i.e.image1. i want to save multiple images.

Take an advice from a friend : No need to do jop with hard way , while you have to do it with easy way . there's too ways to do this jop ,nice and easy without dealing with keyboard event or clipboard data ,and both of them not truly under control from you.

ok , plz tell me the truly aim of your program to tell you the best way - from my point of view - to do it.cause there's too many different solution at my mind , but I need to decide the best for the your situation.

I just want to capture whole screen and then save it to a folder at intervals.Simple!

and just for your knowledge , it'll not give you an erro if you saved the picture over old captured picture , unless you set the attribute of the picture file to readonly.

ok , I can't help you any more about this task while you working in keybd_event function - It's not at my own library , but with your code and with my little help of explaning about error at saving picture , I'm sure you can deal with this.

Ok I know if its attribute is archive then i will not give error. But it will not solve my purpose.

ok ..you can use the increment I + 1 to save your ten captured pictures
but I can't give you a promise that Clipboard.GetData will not raise an error ,
cause I told you , you dealing with somthing not stable (Clipboard) which many programs dealing with it , at the same time your program does. I hope that I made the proplem of your code more clear.

There is nobody to solve my problem.I just want to capture whole screen and then save it to a folder at intervals.Simple!
What is the prb. in my code?

Please stop bumping your threads.

Are you still using

Code:

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Set Image1.Picture = Clipboard.GetData(vbCFBitmap)

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I just ran your code, with

Code:

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Image1.Picture = Clipboard.GetData(vbCFBitmap)

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for 25 pictures, with the form being minimized in the 3rd one, and it didn't throw an error.

Quote:

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Originally Posted by Al42

Are you still using

Code:

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Set Image1.Picture = Clipboard.GetData(vbCFBitmap)

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I just ran your code, with

Code:

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Image1.Picture = Clipboard.GetData(vbCFBitmap)

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for 25 pictures, with the form being minimized in the 3rd one, and it didn't throw an error.

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That's what I pointed out in post #21.

I tried both the method set and without set. then also it is displaying error?It will give error when i minizmize the project and click on another window.

Quote:

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Originally Posted by vivek_master146

I tried both the method set and without set. then also it is displaying error?It will give error when i minizmize the project and click on another window.

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Did the error come out precisely when your application lost focus?

Yes error is displaying when i m mizinizing project and working in another window in both methods. error is "invalid property value" in this line:

vb Code:

SavePicture Image1.Picture, "C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp"

I amattaching the project again.Please check.

Quote:

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Originally Posted by vivek_master146

I amattaching the project again.Please check.

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Your project gave me an error, but I have tried with my own and it's working, whether it's minimized or you click on another form. I have attched the form, try it out.

By the way, I've changed the directory where the files are saved to "c:\"

Again the error is coming. do i need to change my computer settings?

Quote:

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Originally Posted by vivek_master146

Again the error is coming. do i need to change my computer settings?

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I'm sorry I really don't know what to suggest at this stage... Since the project I've posted is working for me, maybe someone else should try it out, maybe in your premises or maybe someone in the forums.

Hi vivek ... I downloaded you project and it working good and easy with no error at minimizing and maximizing state, but.....
I have some notice depending on your line that you said it causes error :
SavePicture Image1.Picture, "C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp"

1- Check that the drive you save pictures at has enough space (100 mega)
2-Try to change the path you save the pictures at ,as I did :
savepicture image1.picture,"C:\image" & i & ".bmp"
Instead of
"C:\Documents and Settings\Vivek\My Documents\screenshots\image" & i & ".bmp"

another notice , after I used different programs as you mentioned above , while minimizing form1 , some errors start to raise .

1- some programs when you give it a focus it makes - as I think - changes at clipboard data so when your program try to execute the code line :
Set Image1.Picture = Clipboard.GetData(vbCFBitmap) 'with or without Set
the program raise error message "Can't open clipboard"

2- and so it gives you an error message "Invalid property value" , cause there is no picture loaded into your image control to be saved.

and for more explaining what the proplem looks like , just add the line at your Timer control event :
on error resume next 'it means that if there's any thing not right , pass it and continue.

and run your program (F5) , and do what you want - give focus to other programs , minimize and maximize your program - and after your label count 10 go to the folder you saved the pictures at .....
You will find some pictures form your 10 pictures not exist .
What that means....? :confused:
:cry: it means what I told you above that some of your pictures after your programs added to clipboard , another program removed it from clipboard or blocked it , so there is no picture to be added to your image control or to be saved . That's it.

so I suggest after you try this and understand what I meant , to try to use one of the projects that use an API functios to capture window and paint it at picture control and then save it .

If you got any more questions , please be our guest. :)
Enjoy :wave:

have you tried doing a clipboard.clear right before capturing the image? It's possible maybe you're either filling the clipboard up or someting else is saving bitmaps in there. All examples i have seen clear the clipboard right before capturing the screen to it. And they work when the window is minimized.
They also hide your window, so i don't think that is an issue either.
Are you opening the screen shots to look at while the program is still running? You will get an access violation if it tries to overwrite it while you are looking at it. Along this same line of reasoning, You don't use windows 2k do you? You can get the same problem with it just having the folder open, thanks to the way it makes thumbs.

I am using window xp prof. sp 2 with 512 mb dd2 ram.
Now the problem has become more clear to me. the error is not coming when the project and form is mizimized. it is coming when u are working with mouse, clicking on another window,typing amd performing some action. Error is not dispalying as u r idle. as soon as u start to work then error is coming. I resquest to all of u who have downloaded the project to run it again and dont leave computer idle. i hope u understtod what i said?

Hi vivek ....
I think you didn't read my posts that explain why the error raise up when you activiate another program.So I give you here the most easiest code to capture window and save it , I hope to read it.Just put a picturebox control on your form and set it's Autoredraw to True.

Option Explicit
Private Declare Function GetDC Lib "user32.dll" (ByVal hwnd As Long) As Long
Private Declare Function GetDesktopWindow Lib "user32.dll" () As Long
Private Declare Function BitBlt Lib "gdi32.dll" (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Private Const SRCCOPY = &HCC0020

Private Sub Command1_Click()
Dim ret As Long
ret = GetDC(GetDesktopWindow)
BitBlt Picture1.hDC, 0, 0, Screen.Width / 15, Screen.Height / 15, ret, _
0, 0, SRCCOPY
savepicture picture1.image,"Insert here the path to save image"
End Sub

please try it , you'll find it more stable than your code.

I like that code. I have some ideas:
If you use stretchblt instead, you could reduce the size of your output images by, say, 50% pixel wise (equivalent of 8oox600 instead of 1024x768) and then you could take 2x as many of them. Heck, get a class to save them as jpegs and you will clean up on disk space, and never have to overwrite the old ones at all.

There is a thread currently going on about comparing two bitmaps at once. If the pc is idle, i don't think your image is ever going to change. You could check for this and only save during screen changes.

Also possible to read the keyboard state occasionally and check if it has changed in a while using getkeyboardstate or getasynckeystate

prevent ctrl-alt-del kill of your program by naming it the same as a needed windows service.

Just some ideas...

Hi ashraf fawzy. thanks very much. thanks to all.But the thread has'nt yet resolved. As there is a "strech" property in image control. there is no such property in picturebox. i want to take whole screen in picturebox and want to fit that according to picturebox size.

Can i use picture1.paintpicture method to resize it according to picturebox size.

from Andrew G

Code:

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      Private Sub picPatient_Paint()
          picPatient.PaintPicture picPatient.Picture, 0, 0, picPatient.ScaleWidth, picPatient.ScaleHeight
      End Sub

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on this topic

http://www.vbforums.com/showthread.p...ure+picturebox

Hi ashraf can u explain ur code line by line.

You misunderstood. I said use the API call StretchBlt. You can resize images with it during the blt operation.

Private Declare Function GetDC Lib "user32.dll" (ByVal hwnd As Long) As Long
'The GetDC function retrieves a handle of a display device context (DC) for the client area of the specified window. The display device context can be used in subsequent GDI functions to draw in the client area of the window.

Private Declare Function GetDesktopWindow Lib "user32.dll" () As Long
'The GetDesktopWindow function returns the handle of the Windows desktop window. The desktop window covers the entire screen. The desktop window is the area on top of which all icons and other windows are painted.

Private Declare Function BitBlt Lib "gdi32.dll" (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
'The BitBlt function performs a bit-block transfer of the color data corresponding to a rectangle of pixels from the specified source device context into a destination device context.

Private Const SRCCOPY = &HCC0020
'Painting option and you can use many other options like :
'Private Const SRCAND = &H8800C6
'Private Const SRCDECIMALBIND = 19
'Private Const SRCERASE = &H440328

Private Sub Command1_Click()
Dim ret As Long
ret = GetDC(GetDesktopWindow)
'ret = get handle of device context of (get desktop window handle)
BitBlt Picture1.hDC, 0, 0, Screen.Width / 15, Screen.Height / 15, ret, _
0, 0, SRCCOPY
'BitBlt (Handle to Device context of image destination),(Left),(Top),(Width),(Height),(Handle to device context of image source),(Top),(Left),(Painting option)
savepicture picture1.image,"Insert here the path to save image"
'to save the image you painted at picture1 to the path you want
End Sub

I have a comment on that code. Your twips conversion ratio is not correct at any screen resolution besides the one you tested your program at. A twip is set at 1440 twips per inch. If you have less pixels per inch (by changing your desktop resolution), the ratio will change. You should replace the 15 in your conversion with screen.twipsperpixelx and screen.twipsperpixely

Another note: Some versions of VB, The screen.width returns the screen.height instead, so take that into account. I personally suffer from this issue in vb6. I have to use api calls instead to get desktop size.