Checking if bit value is false with ASP.NET MVC

Question

0.00/5 (No votes)

See more:

I am trying to check if a bit value is false but I cannot seem to make this work.
I am connected to a database and am working with entity framework.
I am generating a list with a method 'GetAll()', which returns a full list of the forms in the database. I am then trying to create a foreach list that checks if the deleted field is true or false.

It is important to mention that in my sql database, the value of type bit can be null.

What I have tried:

public List<Form> GetAllForms()
{

    var list = GetAll();
    List<Form>filteredList = new List<Form>();

    foreach(var item in list)
    {
        bool checkingDelete = Convert.ToBoolean(item.Deleted);
        if(checkingDelete == false)
        {
                filteredList.Add(item);
        }

    }

Posted 8-Oct-20 23:07pm

Member 13939297

Updated 8-Oct-20 23:16pm

Add a Solution

1 solution

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)

Richard Deeming · Answer 1 · 2020-10-08T23:16:00

Assuming the property on your Form entity is declared as bool? or Nullable<bool>, you can't use Convert.ToBoolean if the value is null.

Instead, compare the value to true or false:

C#

foreach (var item in list)
{
    if (item.Deleted == false)
    {
        filteredList.Add(item);
    }
}

// Or, using LINQ:
List<Form> filteredList = list.Where(item => item.Deleted == false).ToList();

NB: Values which are null will not be equal to false, so those items will be included in the filtered list. If you want to exclude them, you can either change your condition:

C#

List<Form> filteredList = list.Where(item => item.Deleted == false || item.Deleted == null).ToList();

// Or:
List<Form> filteredList = list.Where(item => item.Deleted != true).ToList();

Or you can coalesce the nullable value:

C#

List<Form> filteredList = list.Where(item => item.Deleted.GetValueOrDefault() == false).ToList();

// Or:
List<Form> filteredList = list.Where(item => !item.Deleted.GetValueOrDefault()).ToList();

// Or:
List<Form> filteredList = list.Where(item => (item.Deleted ?? false) == false).ToList();

// Or:
List<Form> filteredList = list.Where(item => !(item.Deleted ?? false)).ToList();