How to get result return from a staic funtions in static class?

Question

0.00/5 (No votes)

See more:

I am confused by an error in the following code:

public static class PublicFunct
{
        public static bool CheckTxtIsNull(Control ctrl)
        {
            bool x;
            
            if (ctrl.GetType() == typeof(TextBox))
            {
                if (ctrl.Text == null || ctrl.Text == "")
                    x = false;
                else
                    x = true;                
            }
                    
            foreach (Control ctrlChild in ctrl.Controls)
            {
                CheckTxtIsNull(ctrlChild);
            }
            
            return x;
        }

Error CS0165 Use of unassigned local variable 'x'

What I have tried:

I can't resolve error. Help me please. Thank!

Posted 19-Jan-18 22:30pm

Member 13451441

Updated 20-Jan-18 7:06am

Add a Solution

Comments

Dotnet_Dotnet 20-Jan-18 4:42am

sir simple define bool x = false;

public static bool CheckTxtIsNull(Control ctrl)
{
bool x = false;

if (ctrl.GetType() == typeof(TextBox))
{
if (ctrl.Text == null || ctrl.Text == "")
x = false;
else
x = true;
}

foreach (Control ctrlChild in ctrl.Controls)
{
CheckTxtIsNull(ctrlChild);
}

return x;
}

3 solutions

Solution 1

x gets assigned only if ctrl.GetType() == typeof(TextBox) is true (because all assignment operations happen inside that if block). If that is false, x will stay unassigned, and that's why the error happens. Make sure to assign something to x also if that statement is false.

(And, unrelated to the error, and perhaps you know, but worth pointing out anyway: you recursively run CheckTxtIsNull in the foreach but you don't do anything with that return value, so that function call is entirely useless at the moment).

Posted 19-Jan-18 22:32pm

Thomas Daniels

Updated 19-Jan-18 22:34pm

v2

Comments

Member 13451441 20-Jan-18 10:29am

Thank you for reply.
I fixed same solution 2 but it's impossible.

Thomas Daniels 20-Jan-18 10:31am

Uhh.. what exactly is impossible?

Solution 2

Simply Define your Boolean variable as

bool x = false instead of bool x;

public static class PublicFunct
        {
            public static bool CheckTxtIsNull(Control ctrl)
            {
                bool x = false;

                if (ctrl.GetType() == typeof(TextBox))
                {
                    if (ctrl.Text == null || ctrl.Text == "")
                        x = false;
                    else
                        x = true;
                }

                foreach (Control ctrlChild in ctrl.Controls)
                {
                    CheckTxtIsNull(ctrlChild);
                }

                return x;
            }
        }

Posted 20-Jan-18 0:54am

Sagar Tajpara

Updated 30-Aug-19 6:33am

v2

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Member 13451441 · Accepted Answer · 2018-01-20T07:06:00

I tried and reached the goal
Check all textbox on form, if textbox null/empty, to be cursor to location null.
Messagebox and break;
AT FORM

namespace LabWinForm
{
    public partial class frmTxtNull : Form
    {
        public frmTxtNull()
        {
            InitializeComponent();
        }

        
        private void btnCheckNull_Click(object sender, EventArgs e)
        {
			///1 - Browse all control
            foreach (Control item in this.Controls)
            {
				///2 - If control is textbox is call static funtion (CheckTxtNull) at class PublicFunct
                if (item.GetType() == typeof(TextBox))
                {
					///3 - If result = True then break;
                    if (iBookFunct.CheckTxtNull(item))
                        return;
                }
            }
			///4 - Execute when all textbox not null/empty
            MessageBox.Show("Hello world");
        }

    }	
}

AT STATIC CLASS

namespace LabWinForm
	public static class PublicFunct
    {
        /// <summary>
        /// Check textbox control is null or empty
        /// </summary>
        /// <param name="ctrl">control textbox</param>
        /// <returns></returns>
        public static bool CheckTxtNull(Control ctrl)
        {
            bool result;
            if (string.IsNullOrEmpty(ctrl.Text))
            {
                MessageBox.Show("Data fields should not be blank.");
                result = true;
                ctrl.Focus();
            }

            else
            {
                result = false;
            }
            return result;
        }


    }

Thank everyone!