out of memory exception in C#?

//  frmBaseClass.cs

public delegate void ProgressStartEventHandle(object sender, int maxValue, int minValue);

public delegate void ProgressChangeEventHandle(object sender,int currentValue,string tips);

public delegate void ProgressEndEventHandle(object sender, string tips);

public partial class frmBaseClass : Form

{

public event ProgressStartEventHandle OnProgressStart;

public event ProgressChangeEventHandle OnProgressChange;

public event ProgressEndEventHandle OnProgressEnd;

private frmProgressBar frmPB = null;

public frmBaseClass()

{

InitializeComponent();

frmPB = new frmProgressBar();

OnProgressStart += new ProgressStartEventHandle(frmPB.ProgressStart);

}

protected virtual void TriggerProgressStart(object sender, int maxValue, int step)

{

if (OnProgressStart != null)

{

frmPB.Show(); // Show ProgressBar Form.

OnProgressStart(sender,maxValue,step);

}

}

protected virtual void TriggerProgressChange(object sender,int currentValue, string tips)

{

OnProgressChange += new ProgressChangeEventHandle(frmPB.ProgressChange);

OnProgressChange(sender,currentValue,tips);

}

protected virtual void TriggerProgressEnd(object sender, string tips)

{

OnProgressEnd += new ProgressEndEventHandle(frmPB.ProgressEnd);

OnProgressEnd(sender, tips);

}

}

 

// frmProgressBar.cs

public partial class frmProgressBar : Form

{

System.Threading.ParameterizedThreadStart pts;

System.Threading.Thread thread;

public frmProgressBar()

{

InitializeComponent();

}

public void ProgressStart(object sender, int maxValue, int minValue)

{

this.progressBar1.Maximum = maxValue;

this.progressBar1.Minimum = minValue;

this.progressBar1.Value = 1;

}

public void ProgressChange(object sender, int currentValue, string tips)

{

this.progressBar1.Value = currentValue;

pts = new System.Threading.ParameterizedThreadStart(SetProgressTips);

thread = new System.Threading.Thread(pts);

thread.IsBackground = true;

thread.Start((object)tips);  // An error has occurred here.

}

public void ProgressEnd(object sender, string tips)

{

pts = new System.Threading.ParameterizedThreadStart(SetProgressTips);

thread = new System.Threading.Thread(pts);

thread.IsBackground = true;

thread.Start((object)tips);

System.Threading.Thread.Sleep(1000);

this.Close(); // Close the ProgressBar Form.

}

private void SetProgressTips(object tips)

{

this.label1.Invoke((Action)(() => label1.Text = (string)tips));

}

}

 

public partial class Form1 : Test.frmBaseClass

{

public Form1()

{

InitializeComponent();

}

private void button2_Click(object sender, EventArgs e)

{

TriggerProgressStart(this, 100, 1);

for (int i = 1; i <=100; i++)

{

TriggerProgressChange(this,i,"Current Progress is:" + i.ToString());

System.Threading.Thread.Sleep(100);

}

TriggerProgressEnd(this, "Completed.");

}

}