making a lock screen in visual c#

Question

5.00/5 (3 votes)

See more:

I need to make a screen which acts as a lockscreen.
what i am trying to make is similar to the following:
'in the utility mosaic which tries to imitate the windows8 start screen, the clock widget when clicked causes a screen to drop down from the top of the screen. this screen is a full screen wallpaper type thing that also shows the time. what is interesting is that it doesn't allow clicks to pass through it to the desktop or to the mosaic app itself. to reach the desktop or the mosaic app, you have to grab this screen at its bottom using the mouse-leftclick-hold and drag the screen upwards to about 3/4 of the screen after which this screen automaticaly retracts. this is somewhat similar to the *slide to unlock* thing on many touchscreen mobiles.'

now, a windows form can be made and dynamically sized to cover the entire screen. It can be set as topmost so that mouse-clicks do not go through it. then one needs to disable alt+tab and 'win' keys to prevent user from directly accessing desktop or taskbar. also disabling form border will disable its minimize, maximize and close buttons.

what i am concerned about is how to make it appear to slide downwards the bottom when the lock is engaged and how to get it to respond to a mouse-click-drag towards the top till some 3/4th of the screen to cause it to retract??? how can i do these animation kind of effect???

plus, i need to have just a single button on this form which can enable the drag-to-retract property so that either a user can engage this slide-to-lock screen and then further lock it in place so that it wont retract or move by dragging until the button is clicked after which the user can slide-it off... like a 2 stage lock.

Posted 14-Jul-11 22:01pm

princektd

Add a Solution

Comments

Manfred Rudolf Bihy 15-Jul-11 4:19am

Ahhh, the scent of specific requirements in the morning ...
Have my 5 for laying out your requirements so nicely.

Philippe Mori 15-Jul-11 21:06pm

Why not make it a screen saver?

princektd 16-Jul-11 8:48am

its kind of a screensaver u can say... but i need it specifically to act as a locking screen for a touchscreen app...

princektd 16-Jul-11 8:48am

thnx Manfred R. Bihy

3 solutions

Solution 1

A slide effect can be achieved by changing the size (and position, in some cases, but sliding to/from the top of the screen doesn't require that) on a timer. All animation of standard controls requires use of a timer.

To respond to a drag, the typical approach is to set a flag on mouse down, unset it on mouse up, and in a mouse move handler perform your drag logic.

Posted 14-Jul-11 22:45pm

BobJanova

Comments

princektd 16-Jul-11 8:49am

i figured i would need a timer. but how do i move the form???

Solution 2

The animation isn't too difficult: all you have to do is cheat.
1) Take a screen grab.

private Bitmap GetScreen()
    {
    Rectangle screenRegiion = Screen.AllScreens[0].Bounds;
    Bitmap grab = new Bitmap(SystemInformation.PrimaryMonitorSize.Width,
                             SystemInformation.PrimaryMonitorSize.Height,
                             PixelFormat.Format32bppArgb);
    using (Graphics screenGraphics = Graphics.FromImage(grab))
        {
        screenGraphics.CopyFromScreen(screenRegiion.Left, screenRegiion.Top, 0, 0, screenRegiion.Size);
        }
    return grab;
    }

2) Make your form cover the entire display, and show the screen grab. This uses a picture box, but you could handle the paint event

private void showPic(Image pic)
    {
    // Get the size of the image
    int xsize = pic.Width;
    int ysize = pic.Height;
    int x = SystemInformation.PrimaryMonitorSize.Width;
    int y = SystemInformation.PrimaryMonitorSize.Height;
    ClientSize = new System.Drawing.Size(x, y);
    FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
    BackColor = System.Drawing.Color.Black;
    Location = new System.Drawing.Point(0, 0);
    int yout = SystemInformation.PrimaryMonitorSize.Height;
    int xout = (int) SystemInformation.PrimaryMonitorSize.Height * xsize / ysize;
    if (xout > SystemInformation.PrimaryMonitorSize.Width)
        {
        //Retain aspect ratio
        yout = (int) SystemInformation.PrimaryMonitorSize.Width * ysize / xsize;
        xout = SystemInformation.PrimaryMonitorSize.Width;
        }
    pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
    pictureBox1.Location = new System.Drawing.Point((SystemInformation.PrimaryMonitorSize.Width - xout) / 2, (SystemInformation.PrimaryMonitorSize.Height - yout) / 2);
    pictureBox1.Size = new System.Drawing.Size(xout, yout);
    pictureBox1.Image = pic;
    }

Don't forget to hide any controls you already have!
4) Using a timer, slowly "slide" your picture down over the screen grab. This is pretty simple: Graphics.DrawImage with an increasing Y offset, and an invalidate.
5) Handle some event so that you can cancel the lock and re-display the normal screen!

Posted 14-Jul-11 22:47pm

OriginalGriff

Comments

princektd 16-Jul-11 8:44am

i need to slide the whole form... say Form1 is the 'home screen' hosting the buttons. one of these buttons is for locking. clicking on this lock button has to create a new instance of a form, say Form2, and have Form2 slide down from the top to the bottom. also, Form2 has to be fullscreen, so size change is not an option... this doesnt mean i have to hide or disable Form1. Form1 must still be active but under Form2 untill Form2 is dragged upwards again to 'unlock'...

Add a Solution

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

lukeer · Accepted Answer · 2011-07-14T22:53:00

To slide down, you need to change Location and/or Size of your wallpaper-showing window. Start near the top, then gradually set your window to move lower and lower.

That for you will need some events to trigger the Location change. Typically you would use a System.Windows.Forms.Timer set to Interval = 40ms.

I personally would also run a System.Diagnostics.Stopwatch to control the window motion. Timer to create the event, Stopwatch to process exact location. This is because Stopwatch.ElapsedMilliseconds's precision is a lot better than that of a Forms.Timer.

So you would have something like

double panningTimeMs = 500D;
private void PanningTimer_Tick( object sender, EventArgs e)
{
    int elapsedMilliseconds = _panningStopwatch.ElapsedMilliseconds;
    if( elapsedMilliseconds > panningTimeMs)
    {
        _panningTimer.Stop();
        elapsedMilliseconds = panningTimeMs;
    }

    int windowTop = -this.Height + ( this.Height * elapsedMilliseconds / panningTimeMs);

    this.Location = new System.Drawing.Point( this.Location.X, windowTop);
}

For detecting the upwards slide, override OnMouseDown. Check mouse position and decide whether it qualifies as movement starting point. Set a member field if it does.

Override OnMouseMove and check whether you're in sliding mode (that's what the member field was for). If so, check mouse position. If it is far enough up the screen, remove the lock.

Finally, override OnMouseUp as well and check for sliding mode. Reset the mentioned member field if mouse position is still to near the bottom to release lock.

For the extra double-lock button, you could use a System.Windows.Forms.CheckBox with Appearance = Appearance.Button. If checked, the button will remain pressed, until you uncheck it. You could then check the Checked property to determine if you do all the other sliding stuff.

making a lock screen in visual c#

3 solutions

Solution 1

Solution 2

Solution 3

Add your solution here

Preview 0

making a lock screen in visual c#

3 solutions

Solution 1

Solution 2

Solution 3

Add your solution here

Preview 0

Existing Members

...or Join us