How can i avoid the flickering while generating screenshots?

Question

1.00/5 (1 vote)

See more:

hi
my goal is to generate screenshots in regular interval of time and save it in a folder.

i am generating screenshots using the following code.

C#

private void timer1_Tick(object sender, EventArgs e)
      {
          this.Hide();
          System.Drawing.Bitmap Bitmap;
          Graphics Graps;
          Bitmap = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);
          Graps = Graphics.FromImage(Bitmap);
          string s = comboBox1.SelectedItem.ToString()+" "+ DateTime.Now.ToString();
          s = s.Replace(':', '.');
          Graps.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);
          Bitmap.Save(@"\\192.168.1.10\Temparea\Screenshotseg\" + s + ".Jpeg", ImageFormat.Jpeg);

          //Bitmap.Save(@"Z:\\Screenshotseg\" + s + ".jpeg", ImageFormat.Jpeg);

          //MessageBox.Show(Application.StartupPath.ToString());
          //Bitmap.Save(@"Screenshots\" + s + ".jpeg", ImageFormat.Jpeg);
          //MessageBox.Show("Your Screen Shot Save in Desktop");
          this.Show();
      }

but when each screenshot is generated flickering of the screen occurs.
How can i avoid the flickering?

Posted 22-Jan-12 18:05pm

jasen.selvaraj

Updated 22-Jan-12 19:59pm

koolprasad2003

v3

Add a Solution

Comments

Sergey Alexandrovich Kryukov 23-Jan-12 0:34am

Just unbelievable! Why doing so? Why?!
--SA

koolprasad2003 23-Jan-12 2:00am

added <pre> tag only.

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Answer 1 · 2012-01-22T18:53:00

This code is just designed to flicker.

If flickers due to Hide/Show and there is nothing you can do. This is not a real flicker though, this is normal rendering of a window when you hide and show it again. Try to run any normally behaving application and quickly hide and show it using the click on the system taskbar. Do you call it "flicker"? No. So, what your application does is not a flicker.

All you can do is re-design your application.

First, I cannot believe you really need to capture a screen periodically. Even if you need so many screen shots, I would assume you only need to make the screen short which are different, when something is changed on the screen. To trigger taking the screenshot, you need to use a global Window Hook. Please see:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms632589%28v=vs.85%29.aspx[^],
http://msdn.microsoft.com/en-us/library/windows/desktop/ms644990%28v=vs.85%29.aspx[^],
http://support.microsoft.com/kb/318804[^].

Now, you cannot install the global Windows Hook in .NET code. According to Microsoft documentation, it should be a native DLL. It can communicate with your application. Some simple approach could be this: your application can run a polling thread taking the screenshot (by the way, since this moment, forget the idea of writing such application without extensive use of threading). The thread should be kept in the wait state by the call to a event wait handle WaitOne method, and a hook handler should simply set this handle (change it to its signaled state).

This part is not easy to implement at all. The detailed description of it would take a really big CodeProject article. You don't have much luck — it is not interesting enough to waste time on it. Your purpose is not clear, please see above.

Finally, let's address what you called "flicker". Your application does not need UI. Even if by some reason it does, you can minimize its window and never show during the acquisition. Show the window again only when a user restores it explicitly using Alt+TAB, Windows+Tab or taskbar. Yes, as simple as that.

At the end, I would like to tell that I cannot believe making a sequence of screenshots using a timer or a periodic thread with Sleep may make any sense. You really need to share your ultimate goal and explain why would you need to do such a weird thing.

—SA

jasen.selvaraj · Answer 2 · 2012-01-26T19:35:00

C#

int screenWidth = Screen.GetBounds(new Point(0, 0)).Width;
            int screenHeight = Screen.GetBounds(new Point(0, 0)).Height;
            Bitmap bmpScreenShot = new Bitmap(screenWidth, screenHeight);
            Graphics gfx = Graphics.FromImage((Image)bmpScreenShot);
            gfx.CopyFromScreen(0, 0, 0, 0, new Size(screenWidth, screenHeight));
            bmpScreenShot.Save("test.jpg", ImageFormat.Jpeg);

How can i avoid the flickering while generating screenshots?

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0