System.NullReferenceException

tanvirtonu's Avatar, Join Date: Aug 2007
Newbie Member
f I just add a simple textbox/richtext box in C# design window and run it, An exception occures- " System.NullReferenceException"

My code frm the code window is as follows-
Code:
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace TestDemo2
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.RichTextBox richTextBox1;
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			//Exception shows here- Highlighted after compile
			this.richTextBox1 = new System.Windows.Forms.RichTextBox();

			this.SuspendLayout();
			//
			// richTextBox1
			//
			this.richTextBox1.Location = new System.Drawing.Point(128, 40);
			this.richTextBox1.Name = "richTextBox1";
			this.richTextBox1.TabIndex = 0;
			this.richTextBox1.Text = "richTextBox1";
			//
			// Form1
			//
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(456, 286);
			this.Controls.AddRange(new System.Windows.Forms.Control[] {
				this.richTextBox1});
				this.Name = "Form1";
				this.Text = "Form1";
				this.Load += new System.EventHandler(this.Form1_Load);
				this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main()
		{
			Application.Run(new Form1());
		}

		private void Form1_Load(object sender, System.EventArgs e)
		{

		}
	}
}
After I run the same code the following message is shown-

"An unhandled exception of type 'System.NullReferenceException' occurred in system.windows.forms.dll

Additional information: Object reference not set to an instance of an object. "

It highlights the following line of the code-

"this.richTextBox1 = new System.Windows.Forms.RichTextBox();"


IT IS really getting on my nerves.What the hell is this exception about. I didnt write a single code in it. I did it frm design window. THen why do they show such an exception. What else to do to get it right. PLs help me.

Last edited by shabbir; 24Aug2007 at 17:22.. Reason: Code block
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
I am not sure why there is an error but it looks like you have just used the Generated code and nothing of your own.
tanvirtonu's Avatar, Join Date: Aug 2007
Newbie Member
Brother where the .Net software cant make it out with its own generated code,You r telling me to add my code. If it cant run a simple program made/coded all by itself, there is no use writing my code.
tanvirtonu's Avatar, Join Date: Aug 2007
Newbie Member
One thing is dat I hav two operating systems.One in drive c and another one(XP)is in drive D and I have installed .Net in XP, I mean drive D. But in Xp I installed MS.Net in drive E bcos there was little space in the system drive-D. Is it making anu problem. I even reinstalled .Net and tried again just after adding a richtextbox.It says the same thing-

"An unhandled exception of type 'System.NullReferenceException' occurred in system.windows.forms.dll

Additional information: Object reference not set to an instance of an object. "

See the problem is in the system.windows.forms.dll.
I dont know what it means. Whatever I add makes no problem except for RichTextBox-this is the main problem of every RICH!! object of the world
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Quote:
Originally Posted by tanvirtonu
Brother where the .Net software cant make it out with its own generated code,You r telling me to add my code. If it cant run a simple program made/coded all by itself, there is no use writing my code.
Try to read the replies. If you are not a good reader you should be trying it out of your own. I have told just the opposite.