Define your own dialog box : Dialog : GUI Windows Forms C# Examples

    
using  System;
using  System.Drawing;
using  System.Collections;
using  System.ComponentModel;
using  System.Windows.Forms;
using  System.Data;

public  class  FormInvokeDialog  :  System.Windows.Forms.Form
{
    private  System.ComponentModel.Container  components  =  null;

    private  System.Windows.Forms.MenuItem  mnuModalBox;
    private  System.Windows.Forms.MenuItem  menuItem1;
    private  System.Windows.Forms.MainMenu  mainMenu1;
    
    private  string  dlgMsg  =  "Pick  a  menu  item";

    public  FormInvokeDialog()
    {
        InitializeComponent();
        CenterToScreen();
    }

    protected  override  void  Dispose(  bool  disposing  )
    {
        if(  disposing  )
        {
            if  (components  !=  null)  
            {
                components.Dispose();
            }
        }
        base.Dispose(  disposing  );
    }

    private  void  InitializeComponent()
    {
        this.menuItem1  =  new  System.Windows.Forms.MenuItem();
        this.mnuModalBox  =  new  System.Windows.Forms.MenuItem();
        this.mainMenu1  =  new  System.Windows.Forms.MainMenu();
        //  
        //  menuItem1
        //  
        this.menuItem1.Index  =  0;
        this.menuItem1.MenuItems.AddRange(new  System.Windows.Forms.MenuItem[]  {
                                                                                    this.mnuModalBox});
        this.menuItem1.Text  =  "Dialogs";
        //  
        //  mnuModalBox
        //  
        this.mnuModalBox.Index  =  0;
        this.mnuModalBox.Text  =  "Show  Modal  Box";
        this.mnuModalBox.Click  +=  new  System.EventHandler(this.mnuModalBox_Click);
        //  
        //  mainMenu1
        //  
        this.mainMenu1.MenuItems.AddRange(new  System.Windows.Forms.MenuItem[]  {
                                                                                    this.menuItem1});
        //  
        //  FormInvokeDialog
        //  
        this.AutoScaleBaseSize  =  new  System.Drawing.Size(5,  13);
        this.ClientSize  =  new  System.Drawing.Size(240,  105);
        this.Menu  =  this.mainMenu1;
        this.Name  =  "FormInvokeDialog";
        this.Text  =  "Parent  Form";
        this.Resize  +=  new  System.EventHandler(this.FormInvokeDialog_Resize);
        this.Paint  +=  new  System.Windows.Forms.PaintEventHandler(this.FormInvokeDialog_Paint);

    }
    [STAThread]
    static  void  Main()  
    {
        Application.Run(new  FormInvokeDialog());
    }

    protected  void  FormInvokeDialog_Resize  (object  sender,  System.EventArgs  e)
    {
        Invalidate();
    }

    protected  void  FormInvokeDialog_Paint  (object  sender,  System.Windows.Forms.PaintEventArgs  e)
    {
        Graphics  g  =  e.Graphics;
        g.DrawString(dlgMsg,  new  Font("times  New  Roman",  24),Brushes.Blue,  this.ClientRectangle);
    }

    protected  void  mnuModalBox_Click  (object  sender,  System.EventArgs  e)
    {
                DialogForm  myForm  =  new  DialogForm();
        myForm.Message  =  dlgMsg;

        myForm.ShowDialog(this);

        if(myForm.DialogResult  ==  DialogResult.OK)
        {
            dlgMsg  =  myForm.Message;
            Invalidate();
        }
    }
}
public  class  DialogForm  :  System.Windows.Forms.Form
{
        private  System.ComponentModel.Container  components  =  null;
    private  System.Windows.Forms.Button  btnCancel;
    private  System.Windows.Forms.Button  btnOK;
    private  System.Windows.Forms.Label  label1;
    private  System.Windows.Forms.TextBox  txtMessage;

        public  DialogForm()
        {
                InitializeComponent();
        this.StartPosition  =  FormStartPosition.CenterParent;            
        }

    private  string  strMessage;

    public  string  Message
    {
        get{  return  strMessage;}
        set
        {  
            strMessage  =  value;
            txtMessage.Text  =  strMessage;
        }
    }


    protected  override  void  Dispose(  bool  disposing  )
    {
        if(  disposing  )
        {
            if  (components  !=  null)  
            {
                components.Dispose();
            }
        }
        base.Dispose(  disposing  );
    }

        private  void  InitializeComponent()
    {
        this.label1  =  new  System.Windows.Forms.Label();
        this.btnOK  =  new  System.Windows.Forms.Button();
        this.btnCancel  =  new  System.Windows.Forms.Button();
        this.txtMessage  =  new  System.Windows.Forms.TextBox();
        this.SuspendLayout();
        //  
        //  label1
        //  
        this.label1.Font  =  new  System.Drawing.Font("Microsoft  Sans  Serif",  12F,  System.Drawing.FontStyle.Bold);
        this.label1.Location  =  new  System.Drawing.Point(12,  8);
        this.label1.Name  =  "label1";
        this.label1.Size  =  new  System.Drawing.Size(240,  48);
        this.label1.TabIndex  =  1;
        this.label1.Text  =  "Type  in  your  message,  and  the  main  window  will  use  it...";
        //  
        //  btnOK
        //  
        this.btnOK.DialogResult  =  System.Windows.Forms.DialogResult.OK;
        this.btnOK.Location  =  new  System.Drawing.Point(16,  104);
        this.btnOK.Name  =  "btnOK";
        this.btnOK.Size  =  new  System.Drawing.Size(96,  24);
        this.btnOK.TabIndex  =  2;
        this.btnOK.Text  =  "OK";
        this.btnOK.Click  +=  new  System.EventHandler(this.btnOK_Click);
        //  
        //  btnCancel
        //  
        this.btnCancel.DialogResult  =  System.Windows.Forms.DialogResult.Cancel;
        this.btnCancel.Location  =  new  System.Drawing.Point(152,  104);
        this.btnCancel.Name  =  "btnCancel";
        this.btnCancel.Size  =  new  System.Drawing.Size(96,  24);
        this.btnCancel.TabIndex  =  3;
        this.btnCancel.Text  =  "Cancel";
        //  
        //  txtMessage
        //  
        this.txtMessage.Location  =  new  System.Drawing.Point(16,  72);
        this.txtMessage.Name  =  "txtMessage";
        this.txtMessage.Size  =  new  System.Drawing.Size(232,  20);
        this.txtMessage.TabIndex  =  0;
        this.txtMessage.Text  =  "";
        //  
        //  DialogForm
        //  
        this.AutoScaleBaseSize  =  new  System.Drawing.Size(5,  13);
        this.ClientSize  =  new  System.Drawing.Size(266,  151);
        this.ControlBox  =  false;
        this.Controls.Add(this.btnCancel);
        this.Controls.Add(this.btnOK);
        this.Controls.Add(this.label1);
        this.Controls.Add(this.txtMessage);
        this.FormBorderStyle  =  System.Windows.Forms.FormBorderStyle.FixedDialog;
        this.MaximizeBox  =  false;
        this.MinimizeBox  =  false;
        this.Name  =  "DialogForm";
        this.Text  =  "Some  Custom  Dialog";
        this.ResumeLayout(false);

    }

    protected  void  btnOK_Click  (object  sender,  System.EventArgs  e)
    {
        strMessage  =  txtMessage.Text;
    }
}