Display if statement variable in messagebox

Question

I'm having issues with displaying the variable within a Message box. What I want to do is display in a messagebox which Combobox hasn't been filled in, it will display this in a list within the messagebox and then stop the user from saving to the database. The error is stating that it is a use of an unassigned variable but I have assigned it at the top of the 'if' statement.

private void btnSaveDB_Click(object sender, EventArgs e)
    {
        if (cmbPolType.SelectedItem == null || 
            cmbPolNum.SelectedItem == null ||
            cmbTPReg.SelectedItem == null || 
            cmbLossType.SelectedItem == null || 
            cmbLossDesc.SelectedItem == null ||
            cmbInsdFault.SelectedItem == null)
        {
            string polType, polNum, lossType, lossDesc, tpReg, insdFault = null;

            if (cmbPolType.SelectedItem==null)
            {
                polType = "Policy Type";
            }

            if (cmbPolNum.SelectedItem==null)
            {
                 polNum = "Policy Number";
            }
            if (cmbLossType.SelectedItem==null)
            {
                lossType = "Loss Type";
            }
            if (cmbLossDesc.SelectedItem ==null)
            {
                lossDesc = "Loss Description";
            }
            if (cmbTPReg.SelectedItem==null)
            {
                tpReg = "TP Reg";
            }
            if (cmbInsdFault.SelectedItem==null)
            {
                insdFault = "Insd at Fault";
            }

            MessageBox.Show("You have not selected options for the following: " + lossDesc );
        }

You have insdFault assigned to null, but lossDesc only declared. Multiple variable declaration and definition doesn't work like that. — Maximilian Gerhardt
– Maximilian Gerhardt, Commented Aug 27, 2016 at 13:35
Just another quick note, if you're wanting to print out which options are at fault, you may want to use a StringBuilder then append to it in each if statement. — Swemoph
– Swemoph, Commented Aug 27, 2016 at 13:42

Steve · Accepted Answer · 2016-08-27 13:59:58Z

3

No lossDesc is not initialized in that way as well as the other strings variables but the insdFault. (The error message points to lossDesc because is the only one used in the remainder of the code).

Instead of initializing each one, I suggest to use a simple List<string> where you add your error messages and type all of them at the end of the test

List<string> missingData = new List<string>();
if (cmbPolType.SelectedItem == null)
    missingData.Add("Policy Type");
if (cmbPolNum.SelectedItem == null)
    missingData.Add("Policy Number");
if (cmbLossType.SelectedItem == null)
    missingData.Add("Loss Type");
if (cmbLossDesc.SelectedItem == null)
    missingData.Add("Loss Description");
if (cmbTPReg.SelectedItem == null)
    missingData.Add("TP Reg");
if (cmbInsdFault.SelectedItem == null)
    missingData.Add("Insd at Fault");

if(missingData.Count > 0)
{
   MessageBox.Show("You have not selected options for the following: " + 
                    Environment.NewLine + 
                    string.Join(Environment.NewLine, missingData.ToArray()));
}
else
{

   ... save to database ? ....
}

This removes the need to use and initialize a bunch of string variables and uses the string.Join method to get the whole error message in a single string with each error on a separate line.

edited Aug 27, 2016 at 13:59

answered Aug 27, 2016 at 13:42

Steve

217k22 gold badges242 silver badges296 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Gecko Over a year ago

This approach is good. It allows for easy adding of extra validation.

Steve Over a year ago

Yes, @stefchri I would also remove that ugly if statement at the beginning because adds only another point of possible errors in case of new combos to check and the gain (if any) is minimal.

Griff Over a year ago

Many thanks for all of your prompt replies. The list is a much better way to proceed with..Thank you !

Collectives™ on Stack Overflow

Display if statement variable in messagebox

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related