there's a problem in paint event

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I have a user control on my project. But it seems that the paint event handler has some problems when it comes to creating a line. After creating a line, I scroll down the user control. Then it create several lines. What should I do?

Posted 2-Jan-11 15:12pm

yummy02

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jerrykid · Accepted Answer · 2011-01-02T15:18:00

Solution 1

Add this code in the first line in paint event

e.Graphics.Clear(Color.White);

Posted 2-Jan-11 15:18pm

jerrykid

Updated 2-Jan-11 15:20pm

v2

Comments

yummy02 2-Jan-11 21:27pm

I'd tried that one, but it did not work. The images in my pictureboxes disappear.

jerrykid 2-Jan-11 21:30pm

So...what things did you do in paint event?

jerrykid 2-Jan-11 21:35pm

Can you post your full codes in paint event function?

yummy02 2-Jan-11 21:50pm

this is my code in paint event:

Graphics g = e.Graphics;
Pen myPen = new Pen(System.Drawing.Color.Red, 5);
g.DrawLine(myPen, pbox.Right, pbox.Bottom, 0, 0);

jerrykid 2-Jan-11 22:08pm

Is this all codes in paint event? Is this code in paint event of pbox_Paint(object sender, PaintEventArgs e)?

jerrykid 2-Jan-11 22:18pm

To help you solve this problem, I think you need to post all codes in you user control, because, this code in paint event does not cause to any error for creating a line.

yummy02 2-Jan-11 22:43pm

that's it: I hope that info could help. Thanks jerrykid!

namespace ClassLibrary1
{
public partial class UserControl1 : UserControl
{
PictureBox pbox1 = new PictureBox();

public UserControl1()
{
InitializeComponent();
}

private void UserControl1_Load(object sender, EventArgs e)
{

XmlDocument xd = new XmlDocument();
xd.Load(@"\XML.xml");
XmlNodeList xnl = xd.SelectSingleNode("root").ChildNodes;
foreach (XmlNode xN in xnl) //for each node in xml file
{
XmlElement xElem = (XmlElement)xN;
XmlNodeList c = xElem.GetElementsByTagName("c");
XmlNodeList x = xElem.GetElementsByTagName("x");
XmlNodeList y = xElem.GetElementsByTagName("y");
XmlNodeList loc = xElem.GetElementsByTagName("loc");

for (int a = 0; a < c.Count; a++)
{
int x1 = Convert.ToInt32(x[a].InnerText);
int y1 = Convert.ToInt32(y[a].InnerText);
pbox1 = new PictureBox();
pbox1.Location = new Point(x1, y1);
Image image = Image.FromFile(loc[a].InnerText);
pbox1.ImageLocation = loc[a].InnerText;
pbox1.Load(loc[a].InnerText);
pbox1.Height = 100;
pbox1.Width = 100;
pbox1.SizeMode = PictureBoxSizeMode.StretchImage;
pbox1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
pbox1.Paint += new PaintEventHandler(pbox1_Paint);
panel1.Controls.Add(pbox1);

}
}
}

void pbox_Paint(object sender, PaintEventArgs e)
{

Graphics g = e.Graphics;
Pen myPen = new Pen(System.Drawing.Color.Black, 3);
g.DrawLine(myPen, pbox1.Left, pbox1.Top, 1, 1);
myPen.Dispose();

}

}
}

jerrykid 2-Jan-11 23:09pm

Hi,

I try your control in my project, but there isn't any error when creating a line, you make me surprise. Please see other codes in the form which use this user control.

Sandeep Mewara 3-Jan-11 0:59am

5! for the effort and follow up.

yummy02 3-Jan-11 2:28am

Hi,

There's a problem, I wasn't able to view the designer of my form. I can only view the codes. But viewing the codes and the form may be useless because I did not store any codes in my form, only in my user control.

yummy02 3-Jan-11 3:26am

By the way, right now, it does not create several lines but the lines (when I move the mouse downward) dislocate, or may I say the line changes from the line that I assumed to the line that I did not expect.