combobox selected value in c#

2
votes

I am working on C#.net windows application. i am filling combobox on my winform by using follows.

cmbEMPType.DataSource = objEntityManager.EmployeeTypes();
cmbEMPType.DisplayMember = "EMPTypeName";
cmbEMPType.ValueMember = "EMPTypeId";

where objEntityManager.EmployeeTypes(); in the manager method that gets the List from Linq to sql server. this is working fine.

but as i select the item form combo box, and clicked the button then in the button click event i am getting cmbEMPType.SelectedValue as EmpType return type rather than its Id. why should this? I don't want to create one more EmpType object. need simple selected value. also can not keep faith with SelectedIndex. it may varies for item each time.

**Edited**
      public List<EMPType> EmployeeTypes()
        {
            List<EMPType> EMPTypeList = null;
            try
            {
                if (CommonDataObject.dataContext.EMPAllTypes.Any())
                {
                    EMPTypeList = CommonDataObject.dataContext.EMPAllTypes.ToList();
                }
                return EMPTypeList;
            }
            catch
            {

                return EMPTypeList;
            }

        }

Edited

   private void btnSave_Click(object sender, EventArgs e)
        {

iEMPTypeId = cmbEMPType.SelectedValue;
}

here I must get inte. but asking of create the EMPType object.

3
c#winformscomboboxselectedvalue
Are you sure you're not using cmbEMPType.SelectedItem? This would normally get the selected object (EmpType), while cmbEMPType.SelectedValue would get the property specified in 'ValueMember'. – Edwin de Koning
Yes,i am sure. I checked it thrice. but unfortunately there is SelectedValue. in fact you can also check its return type . it showing 'object'. – Red Swan
it will always return object because the value can be of any type so you need to cast it anyway. Please post more code as I asked in my other comment and we'll see what's going on. – Shadow Wizard Is Vaccinated V3
what do you mean by "asking of create the EMPType object"? Do you get error? If so post here the full error message.. – Shadow Wizard Is Vaccinated V3

3 Answers

1
votes

This is the correct and expected behavior, you can't change it.

SelectedValue should return the type of the property, e.g. if EMPTypeId is integer it should return integer - please post more code so that we can try figuring out why you get different return value.

If by any chance you're using SelectedItem then have such code to get the ID:

 int selectedID = (cmbEMPType.SelectedItem as EmpType).EMPTypeId;

To handle cases when there's nothing selected:

object oSelectedEmp = cmbEMPType.SelectedItem;
int selectedID = oSelectedEmp == null ? -1 : (oSelectedEmp as EmpType).EMPTypeId;
1
votes

The problem is the sequence of your code. Please remove the first line code to the last line. You will get an int value (iEMPTypeId) from cmbEMPType.SelectedValue.

cmbEMPType.DisplayMember = "EMPTypeName"; 
cmbEMPType.ValueMember = "EMPTypeId"; 
cmbEMPType.DataSource = objEntityManager.EmployeeTypes();

iEMPTypeId = cmbEMPType.SelectedValue
0
votes

Another option is to override the toString function in your EMPType class. As Edwin de Koning stated "If no ValueMember is specified it gives a ToString() representation."

Something like (I cant test it at the moment):

public override string ToString()
{
    return this.ID;
}

You can check out this article: http://msdn.microsoft.com/en-us/library/ms173154(v=vs.80).aspx