C# ASP.NET Webforms: TextBox(Not Textbox.Text) is coming out null. How do you fix this?

Question

I am testing out a webform to save strings from a textbox. The program stops running when I press a button programmed to save the info into an array. Here's the error:

System.NullReferenceException occurred HResult=0x80004003 Message=Object reference not set to an instance of an object. Source=TS_Webform StackTrace: at TS_Webform.Forms.Login.registerUser() in C:\Users\k20\Source\Repos\TS_Webform\TS_Webform\Forms\Login.aspx.cs:line 105 at TS_Webform.Forms.Register2.Button1_Click(Object sender, EventArgs e) in C:\Users\k20\Source\Repos\TS_Webform\TS_Webform\Forms\Register2.aspx.cs:line 25

heres the method that it the message directs me to:

   public static void registerUser()
   {
        User newUser = new User();
        Register2 register2 = new Register2();
        newUser.strName = register2.TextBox1.Text;//Stops here 
        newUser.strPW = register2.TextBox2.Text;
        //newUser.strEmail = textBox3.Text;
        newUser.strPhone = register2.TextBox3.Text;
        newUser.strHas = register2.TextBox4.Text;
        newUser.strNeeds = register2.TextBox5.Text;
        userArray[I(userArray)] = newUser;
   }

I tried numerous things like changing the Textbox-declaration line on Register2.aspx.designer.cs from protected to public and public static and neither has worked.

Possible duplicate of [What is a NullReferenceException, and how do I fix it?](https://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Tetsuya Yamamoto, Aug 02 '17 at 03:47
@Tetsuya Yamamoto. I don't think a regular nullReference Exception applies here. It's a control. — Kevin Serrano, Aug 02 '17 at 03:59
First delete the control in Register2.aspx. after that take new textbox. then go to Register2.aspx.designer.cs file and change "private System.Windows.Forms.TextBox textBox1;" to "public System.Windows.Forms.TextBox textBox1;" — Durgesh Pandey, Aug 02 '17 at 04:05

score 0 · Answer 1 · answered Aug 02 '17 at 03:55

This sort of thing can happen when your code behind gets out of sync with your web form markup. For every control that is in your markup, there is supposed to be a protected member in the code behind class; if they do not match up properly, you can get an orphaned control, or the member can return null.

The simplest way to fix this is to completely delete the control (from both markup and code behind) and add it again using the form designer.

score 0 · Answer 2 · answered Aug 02 '17 at 04:28

I fixed the problem. The method, registerUser(), is on a different page, Login.aspx.cs. I moved that method to Register2.aspx.cs. For whatever reason when the button on Register2 calls the method from Login.aspx.cs it resets the textboxes to null or the method isn't really responding to the fact that Register2 is open/loaded.

C# ASP.NET Webforms: TextBox(Not Textbox.Text) is coming out null. How do you fix this?

2 Answers2