multiple classes

Hello,

I want to build a multiple class aplication containing a picturebox.

I want to call OnPaint-Event in this application.

During the debugging-execution I get the error-message "StackOverflowException was not managed"(Form1.Designer.cs; this.ResumeLayout(false)).

my code is the following:

Form1.Designer.cs
namespace WindowsFormsApplication1
{
partial class Form1
{
///
/// Erforderliche Designervariable.
///
private System.ComponentModel.IContainer components = null;
private void InitializeComponent()
{
this.pictureBox1 = new System.Windows.Forms.PictureBox();
((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
this.SuspendLayout();
//
// pictureBox1
//
this.pictureBox1.Location = new System.Drawing.Point(12, 25);
this.pictureBox1.Name = "pictureBox1";
this.pictureBox1.Size = new System.Drawing.Size(268, 229);
this.pictureBox1.TabIndex = 0;
this.pictureBox1.TabStop = false;
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.pictureBox1);
this.Name = "Form1";
((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
this.ResumeLayout(false);
}
public System.Windows.Forms.PictureBox pictureBox1;
}
}
Form1.cs
using System;
using System.Drawing;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
Form2 itsme;
public Form1()
{
InitializeComponent();
itsme = new Form2();
}
}
}
Form2.cs
using System;
using System.Drawing;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
class Form2 : Control
{
Form1 itsme2;
public Form2()
{
itsme2 = new Form1();
itsme2.pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(this.OnPaint);
}
private void OnPaint(object sender, PaintEventArgs e)
{
MessageBox.Show("Hi");
}
}
}

If you can help me, many thanks.

You are creating new Form2() in constructor of Form1():

public partial class Form1 : Form
{
Form2 itsme;
public Form1()
{
InitializeComponent();
itsme = new Form2();
}
}

Then you are creating Form1() in constructor of Form2():

class Form2 : Control
{
Form1 itsme2;
public Form2()
{
itsme2 = new Form1();
itsme2.pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(this.OnPaint);
}

This way it may compile and build, but when you run, it's going to create infinite number of form1() and form2() objects, then it will run out of memory, and you will get StackOverflowException.

You need to modify your code so that the compiler does not go in this infinite cycle.

1 Reply

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Nilesh Shah9y ago
You are creating new Form2() in constructor of Form1():
public partial class Form1 : Form
    {
        Form2 itsme;
        public Form1()
        {
            InitializeComponent();
            itsme = new Form2();
        }
    }
Then you are creating Form1() in constructor of Form2():
class Form2 : Control
    {
        Form1 itsme2;
        public Form2()
        {
            itsme2 = new Form1();
            itsme2.pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(this.OnPaint);
        }
This way it may compile and build, but when you run, it's going to create infinite number of form1() and form2() objects, then it will run out of memory, and you will get StackOverflowException.

You need to modify your code so that the compiler does not go in this infinite cycle.