Link to home
Start Free TrialLog in
Avatar of Brian
BrianFlag for United States of America

asked on

Retrieving CheckBoxList values in C#

Hello, I have the following code below that retireves values from my database that I would like to bind to the CheckBoxList control. However, I have a red line under the word "Information" that I can't seem to figure out. Please keep in mind that someone else gave me this code to use which is why i'm having issues.


                    // Check for CheckBox value if empty then the CheckBox is empty
                    foreach (DataRow Row in dtStudent.Rows)
                    {
                        if (!Information.IsDBNull(Row["testid"]))    <------ Message on this line.,
                        {
                            cblTests.Items.FindByValue(Row["testid"].ToString()).Selected = true;
                        }
                    }
Avatar of Carl Tawn
Carl Tawn
Flag of United Kingdom of Great Britain and Northern Ireland image

Well, "Information" in your code sample must refer to either a static class, or some IDataReader derived object. The red line means it isn't recognised, which will either mean you're missing a reference/namespace or the object being refered to is out of scope.
Additionally, just about any time you receive a squiggly in VS (green or red), you can mouse over the offending text and you should receive a popup describing what VS is having an issue with.
Avatar of Brian

ASKER

Well not sure if this helps but I tried to convert the VB code that I used before to C# and that may be where the problem is, but I don' know how to fix it :(.

VB Code:

                    ' Check for CheckBox value if empty then the CheckBox is empty
                    For Each Row As DataRow In dtStudent.Rows
                        If Not IsDBNull(Row("testid")) Then
                            TestList.Items.FindByValue(Row("testid").ToString()).Selected = True
                        End If
                    Next


C# code that was convert from above.

                    foreach (DataRow Row in dtStudent.Rows)
                    {
                        if (!Information.IsDBNull(Row["testid"]))
                        {
                            cblTests.Items.FindByValue(Row["testid"].ToString()).Selected = true;
                        }
                    }
You must use System.Convert.IsDBNull instead of Information.IsDBNull. Information class is in Microsoft.VisualBasic assembly which is not referenced in C# projects by default.
Try:

if (System.Convert.IsDBNull(Row["testid"]))
{
   // code here
}

Open in new window

Avatar of Red-LineNetworks
Red-LineNetworks

Hi,

Information lives in the VB NameSpace. Try the below or a variant of it this.

if (!(IsDbNull(ds.Tables[1].Rows[i]["testid"]))
  {
      cblTests.Items.FindByValue(Row["testid"].ToString()).Selected = true;
  }

Hope this helps.

Thanks,
Red-LineNetworks
use the simplest one
if (ds.Tables[1].Rows[i]["testid"] != null)
  {
      cblTests.Items.FindByValue(Row["testid"].ToString()).Selected = true;
  }
@ghayasurrehman

DBNull is not the same as null. Your example is flawed.
Avatar of Brian

ASKER

hi ghayasurrehman,

When i add your code i'm told that the name "ds" and "i" are not in the current context.
Just use System.Convert.IsDBNull instead of Information.IsDBNull in your first code.
Avatar of Brian

ASKER

Hello everyone,

for some reason when I run my code the values are not getting populated to my CheckBoxList control. Please see what I currently have. I need the code mentioned above to bind the values from the DB to the CheckBoxList control.

                    foreach (DataRow Row in dtStudent.Rows)
                    {
                        if (System.Convert.IsDBNull(Row["testid"]))
                        {
                            cblTests.Items.FindByValue(Row["testid"].ToString()).Selected = true;
                        }
                    }
Avatar of Brian

ASKER

Hi ghayasurrehman,

Your solution in post 33640896 did not work.
Avatar of Brian

ASKER

Hi mehdi_javan,

This did not work either.
>>  Hi ghayasurrehman,

>>  Your solution in post 33640896 did not work.

Of course it did not. Read post #33641588.

Perhaps you can try:
foreach (DataRow Row in dtStudent.Rows)
{
    if (!(Row.IsNull("testid"))
    {
        cblTests.Items.FindByValue(Row["testid"].ToString()).Selected = true;
    }
}

Open in new window

ASKER CERTIFIED SOLUTION
Avatar of kaufmed
kaufmed
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of Brian

ASKER

Thank you. That worked out GREAT!!!!