BOOL FLAG Problem in Paint Handler - C# Discussion Boards

1-Oct-05 9:16

Suppose I have this:

public Pen[] activePen = new Pen[] { new Pen( Color.Blue ), new Pen( Color.Green ), new Pen(Color.Red) };

How to infinitely cycle through the 3 Pens?

thanx

Robert Rohde1-Oct-05 10:20

1-Oct-05 10:20

Like this?

int i = 0;
while (true) {
i = i % 3;
Pen nextPen = activePen[i];
//Do something with nextPen
i++;
}

Anonymous1-Oct-05 10:30

1-Oct-05 10:30

That works-thanks-- but I have one Pen array for the form and
several different g.DrawLine calls to put a few different colored
lines on the form due tied to text boxes --- thanks again

Robert Rohde1-Oct-05 11:45

1-Oct-05 11:45

Well you don't need the while loop. Instead make a private member out of i and put call this method to get a Pen:

//member of your form
private int _penIndex = -1;

private Pen GetNextPen() {
_penIndex = (_penIndex + 1) % 3;
return activePen[_penIndex];
}

BOOL FLAG Problem in Paint Handler

Member 23224411-Oct-05 11:53

Member 2322441

1-Oct-05 11:53

HI, I WAS WONDERING IF YOU KNOW HOW TO WRITE A CODE TO A DOWNLOAD PAGE?
IF SO CAN YOU PLEASE HELP ME?
I JUST DON'T UNDERSTAND HOW TO DO IT...

dontunderstand

Anonymous1-Oct-05 7:28

Re: BOOL FLAG Problem in Paint Handler

1-Oct-05 7:28

I have code that will draw a line on a form. When I hard code it to draw the line it works fine, meaning every time
the form launches a line is drawn. Now i want to set a bool flag and pass it in as a conditional statement to drawn the
line when the Button1 is clicked. I know I'm missing something obvious.

public class Form1 : System.Windows.Forms.Form
{
//Member fields.
private bool drawLine1 = false;..............etc
///////////////////////////////////////////////////////////////////////////

private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
if(drawLine1) //DRAW LINE 1 IS ALWAYS FALSE.....
DrawComplexNumber(e.Graphics);.............etc

//////////////////////////////////////////////////////////////////////////

private void Button_1OK_Click(object sender, System.EventArgs e)
{
drawLine1 = !drawLine1;
Invalidate();
}

How do I fix it? Please -- need a "nuts and bolts" answer, not an "abstract" explanation. Thanks a lot in advance....

Robert Rohde1-Oct-05 7:42

Re: BOOL FLAG Problem in Paint Handler

1-Oct-05 7:42

The code seems to be ok but I noticed that your button click eventhandler has a strange name. You should probably check if the click event of the button is really bound to that method.
Just check (eg by setting a brakepoint) if the drawLine1 = !drawLine1 is being hit and if drawLine1 has the correct contents afterwards.
Then check if you prpbably set drawLine1 back to false somewhere else in your code. Doing some Console.WriteLine("DrawLine1: " + drawLine1.ToString()) here and there should also help you to trace down the problem.

Hope you don't feel this answer is abstract but if you test this code in an empty form you will see that it works and that the error must come from somewhere else.

Anonymous1-Oct-05 9:11

Re: BOOL FLAG Problem in Paint Handler

1-Oct-05 9:11

You were absoutely right. Thought I was going nuts-- thanks
works fine now

Mahesh Kumar V K2-Oct-05 23:16

Mahesh Kumar V K

2-Oct-05 23:16

Try out this code as an example -

public class Form1 : System.Windows.Forms.Form<br />
	{<br />
		private System.Windows.Forms.Button button1;<br />
		private bool drawline = false;<br />
		private int radius = 25;<br />
		private int green = 10;<br />
		private int red = 10;<br />
		private int blue = 10;<br />
         }<br />
<br />
<br />
private void Button_1OK__Click(object sender, System.EventArgs e)<br />
{<br />
drawline = !drawline;<br />
			Random r = new Random(100);<br />
			Int32 x = Int32.Parse(r.Next().ToString().Substring(1,2));<br />
			Int32 y = Int32.Parse(r.Next().ToString().Substring(1,3));<br />
			<br />
			if (green < 230)<br />
                green += 10;<br />
			<br />
			if (blue < 230)<br />
				blue += 10;<br />
			<br />
			if (red < 230)<br />
				red += 10;<br />
<br />
			if (drawline)<br />
			{<br />
				System.Drawing.Graphics g = this.CreateGraphics();<br />
				Point P = new Point(x,100);<br />
				Point p1 = new Point (100,y);<br />
				Color j = Color.FromArgb(red,green,blue);<br />
				Pen Pe = new Pen(j);<br />
				<br />
				g.DrawEllipse(Pe,x,x ,radius, radius);<br />
				radius += 20;<br />
			}<br />
			else<br />
			{<br />
				System.Drawing.Graphics g = this.CreateGraphics();<br />
				Point P = new Point(x,100);<br />
				Point p1 = new Point (100,y);<br />
				Color j = Color.FromArgb(red,green,blue);<br />
				Pen Pe = new Pen(j);<br />
				<br />
				g.DrawEllipse(Pe,y,y ,radius, radius);<br />
				radius += 20;<br />
				this.Refresh();<br />
			}<br />
}

Regards
Mahesh

Property Builder?

Sled Dog1-Oct-05 5:46

Sled Dog

1-Oct-05 5:46

Is there a property build for a DataGrid in a C# Windows Application?

I have used this feature when building web applications, but it does not appear to be present as I am building a Windows application and want to do a basic layout for my datagrid without manually constructing the data columns and features.

Thanks.

SD

Re: Property Builder?

David Stone1-Oct-05 19:38

David Stone

1-Oct-05 19:38

The WinForms DataGrid is really inflexible if you're used to using the asp:DataGrid control. I'm afraid you're going to have to manually construct the stuff you want.

Picture a huge catholic cathedral. In it there's many people, including a gregorian monk choir. You know, those who sing beautifully. Then they start singing, in latin, as they always do: "Ad hominem..."
-Jörgen Sigvardsson

Re: Property Builder?

Sled Dog2-Oct-05 2:38

Sled Dog

2-Oct-05 2:38

Thanks...I was afraid of that.

William

Resize the user defined control

Ming Luo1-Oct-05 5:45

Ming Luo

1-Oct-05 5:45

Hi all
I want to make a user defined control which combine a textbox and DateTimepicker. I write the following code for the Resize event

Size wholesize = this.Size;
int x = wholesize.Width;
wholesize.Height = 21;
Point location = new Point(x - 20, 21);
this.calendar.Location = location;

Size newsize = new Size(wholesize.Width-20, 21);
this.textbox.Size = newsize;

But this code doesn't work, could anybody tell me how to redraw the user control, when I resize it???
Thanks in advance!

Asura

Re: Resize the user defined control

Robert Rohde1-Oct-05 7:50

Re: modify Lunar Lander game

1-Oct-05 7:50

Hmmm... you give us some code which you say doesn't do what you want it to do. But you also don't describe what you exactly want to do... Are we going to guess what you want?

You'll have to explain a bit more if we should help you. But here is a more general tip:

Instead of calculating the new sizes yourself you should use the docking and/or anchoring mechansims of .Net controls. If you want a DateTimePicker at the top and a TextBox filling out the rest of the control you would assign DockStyle.Top to the Dock property of the DateTimePicker and DockStyle.Fill to the TextBox.
Note that when using docking the order of the controls in the form are relevant (and can be changed via the designer).

modify Lunar Lander game

nume1-Oct-05 5:41

nume

1-Oct-05 5:41

Guys,

I need your help..

I need to modify the difficulty level of the lunar lander game..
is it possible to change the dy to .5?? is there any better suggestions in here??

private void timer1_Tick(object sender, System.EventArgs e) {
//code that should happen on every timer tick (10 times/sec)

//account for gravity
dy+= .5;

//increment score for being alive
score += 100;

//show ordinary (no flames) lander
picLander.Image = myPics.Images[0];

moveShip();
checkLanding();
showStats();
} // end timer tick

thanks...

Robert Rohde1-Oct-05 7:56