Re: Change color of ten or more PictureBoxes - C# Discussion Boards

27-Aug-09 0:48

Hi, all,

I am doing a project like this. I have ten or more PictureBoxes, and I have customed methods for both MouseDown and MouseUp of those PictureBoxes, then when I MouseDown one PictureBox and MouseUp the other, I need to change the color of those PictureBoxes between these two. I am thinking to do this by one method like ColorChanged(), and I want this method can always change color of those PictureBoxes even though user trigger the MouseDown and MouseUp events over and over, is this possible? Pls, give me some coding suggestions! Thank you! Best Regards.

------------------------
I won't never ever give up!

Henry Minute27-Aug-09 1:05

27-Aug-09 1:05

Leapsword wrote:
Pls, give me some coding suggestions!

What have you tried already?
Show us some code that is giving problems with an explanation of the exact problem.

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Lyon Sun27-Aug-09 1:50

27-Aug-09 1:50

Hi,
Here is part of the code for that user control which I am working on. Truely there are some bugs here, but never mind. What I need to know is how I can code in that ColorChanged() method so that I can change the color of those PictureBoxes in between. Thank you and BR!

public DateTime getTimeAt(int x, int y)
{
    DateTime selectedTime = new DateTime();
    Random rnd=new Random();

    int hour = (y - 10) / 20 + 8;
    int minute = Convert.ToInt32((x - 25) / 50) * 10 + rnd.Next(1,9);

    if (minute>59)
    {
        minute = 59;
    }

    selectedTime = DateTime.Today;
    selectedTime = selectedTime.AddHours(hour);
    selectedTime = selectedTime.AddMinutes(minute);

    return selectedTime;
}

private void OnMouseDown(object sender, MouseEventArgs e)
{
       StartTime = getTimeAt(e.X, e.Y);
       Updating();
}

private void OnMouseUp(object sender, MouseEventArgs e)
{
    EndTime = getTimeAt(e.X, e.Y);
    Updating();
}

public void ColorChanged(int x, int y)
{
    ////What I need is how to code here...
}

public void Updating()
{
    maskedTextBox1.Text = StartTime.ToString("hhmm");
    maskedTextBox2.Text = EndTime.ToString("hhmm");
}

---------------------------
I won't never ever give up!!

Henry Minute27-Aug-09 2:14

27-Aug-09 2:14

There are two approaches that spring to mind, but before I suggest them would you please confirm the impression I got from your first post.

You want to do this when the user presses the mouse button in one picturebox (MouseDown), moves the mouse (without releasing the button) to another picturebox and then releases the button (MouseUp).

Please confirm that I have understood this correctly.

Lyon Sun27-Aug-09 2:38

27-Aug-09 2:38

Hi, Henry,
Thank you for your quick reply! YES! That's what I mean, I really need your help. Thank you so much.

I won't never ever give up!!

Henry Minute27-Aug-09 3:00

27-Aug-09 3:00

Option 1 (probably the easiest)

Declare two class level PictureBox variables, one for the first (mousedown) and one for the second (mouseup).
In the MouseDown and MouseUp event handlers, identify the PictureBox where the event occurred and assign it to the correct variable.
Add a call to ColorChanged() at the end of the MouseUp handler

I'll do the MouseDown, from that you can work out how to do MouseUp

private PictureBox firstBox = null;
private PictureBox secondBox = null;
private void OnMouseDown(object sender, MouseEventArgs e)
{
    PictureBox pb = sender as PictureBox;
    if (pb != null)
    {
        firstBox = pb;
    }
    else
    {
        firstBox = null;
    }
    StartTime = getTimeAt(e.X, e.Y);
    Updating();
}

after making the changes to MouseUp your ColorChanged() should firstly check if firstBox or secondBox is null, and if so return (nothing to do if you don't have two PictureBoxes). then it is simply a matter of firstBox.BackColor = Color.Blue; (same for secondBox), or however you want to set the color.

I won't give you the second idea unless you don't think this will work as it is far more complicated.

Lyon Sun27-Aug-09 3:53

27-Aug-09 3:53

Heh,
Great! Thank you, Henry! I will try this option now. After I do this, I will post what I got here then, pls keep an eye on this post. Thanks a lot.

Liang

I won't never ever give up!!

Lyon Sun27-Aug-09 20:34

27-Aug-09 20:34

Hi,Henry,
I am sorry to say this. But it seems we had some misunstanding, I guess I need you option two. In my project, I have more than two PictureBoxes, and I want to make it to have the function that user press button on one PictureBox without releasing(MouseDown), and move to another one, then release it(MouseUp). But there might be also PictureBoxes between these two PictureBoxes. Here I cut a sample picture of part of my design, I hope you can give me some help.

Oh, NO! I can't insert a picture into this post. Damn.
Henry, if you still confuse what I am saying cuz my english is so sucks. Could you pls reply me by e-mail: sunly917@gmail.com. I can send the picture to your mailbox.

Thank you and BR!
Liang

Henry Minute28-Aug-09 2:45

28-Aug-09 2:45

I'm afraid that Option 2 would not help in the circumstances as you now describe them, since it was simply a more complicated way to do the same as Option 1.

The only way to do what you want, in the way that you want to do it, that I can think of, is to slightly modify the code I have already given you. Basically what you need to do is to handle the MouseMove event of the control hosting your PictureBoxes. Each time the event fires it should iterate over all the PictureBoxes and test if the cursor location is within the PB pb1.Bounds.Contains(e.Location), or similar and if so, add it to a list and break out of the iteration. Therefore instead of the firstBox and secondBox you will need a collection, I would suggest List<PictureBox>. Don't forget to Clear() it on MouseDown and to add the first and second boxes to it. then in your ChangeColour iterate over the collection and do your recolouring stuff on each PB in it.

The problem with doing things in the way that you want is that if the user moves the mouse very, very quickly, one of the PBs could get missed.

[Edit]
An alternative to my suggested MouseMove approach, would be to calculate a path from the MouseDown point to the MouseUp point and then test for a PB at intervals along that path. The interval would depend on the size of the PBs.
[/Edit]

[Edit * 2]
You could of course combine the two approaches. Have a class level GraphicsPath instance, on MouseDown create a new GraphicsPath e.g. myClassLevelGP = new GraphicsPath(). Make a note of the MouseDown point. myClassLevelStartPoint = e.Location;. Then in the MouseMove handler.

myClassLevelGP.AddLine(myClassLevelStartPoint, e.Location);
myClassLevelStartPoint = e.Location;

Then in the MouseUp handler put the same two lines of code.

What you will end up with is a GraphicsPath containing lots and lots of tiny lines, tracking the path the mouse has taken.
Then in the ColorChange method you will have to iterate over the points contained in the path (look up GraphicsPath.PathPoints and GraphicsPath.PathData for suitability), and for each point iterate over the PBs and pb.Bounds.Contains(point) as mentioned above.

That's a lot of points * a lot of PBs and could take some time, not to mention the problems from fast mousing mentioned above.

You might be better off by rethinking your approach. For example, allowing users to Ctrl-Click on the PBs they want to recolour adding them to the list. They would of course have to click a button or something to trigger the recolouring and any click without Ctrl should clear the list.
[/Edit * 2]

I hope that at least part of my ramblings is of use. Smile | :)

Lyon Sun28-Aug-09 9:27