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Old November 5th, 2003, 05:35 PM
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Default Combo Boxes

When I try to set the value member of a combo box.

cmbCombo.valuemember = "fieldname"

The value that this is returning is the string "fieldname".

It is not actually returning the value that I expected --> "fieldID".

What am i doing wrong?
 
Old November 7th, 2003, 01:37 AM
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The ValueMember property isn't designed to be used in code. You probably have to give it an object of some type. I would use the DataValueField property instead.


Bill Sempf
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Old November 7th, 2003, 11:20 AM
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Could you elaborate, please.

 
Old November 7th, 2003, 11:26 AM
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Are you trying to set the VALUE of a combobox? Or are you trying to set the field name for the value property of the options when you databind it?

Peter
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Old November 7th, 2003, 12:04 PM
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I have already flooded the combobox with the data that I need (FacilityName), this is the information that I want the user to see. Now I want the (FacilityID) to be with each FacilityName, with the FacilityID hidden. I need the FacilityID so I can write that back to SQL when a user chooses a FacilityName.

Hopefully this makes sense, if not let me know.

 
Old November 7th, 2003, 01:03 PM
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(Sorry for the repost, please ignore in email. Somehow I replied quoted instead of fixing something, then deleted both instead of just one. )
Ah ok. I think what you are looking for is DisplayMember.

From the MSDN docs...
To bind a ComboBox or ListBox control
  • Set the DataSource property to a data source object. Possible data sources include a data table, a data view, a dataset, a data view manager, an array, or any class that implements the IList interface.
  • Set the DisplayMember property to the name of a column in the data source object:
    ' Visual Basic

    Private Sub BindComboBox()
      ComboBox1.DataSource = DataSet1.Tables("Suppliers")
      ComboBox1.DisplayMember = "ProductName"
    End Sub

    // C#
    private void BindComboBox()
    {
      comboBox1.DataSource = dataSet1.Tables["Suppliers"];
      comboBox1.DisplayMember = "ProductName";
    }

Peter
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Old November 7th, 2003, 01:43 PM
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I have no problem setting the DisplayMember (FacilityName), that works fine. What I need to do is set the ValueMember (FacilityID).

When I set the ValueMember

(cmbFacilityname.ValueMember = "FacilityID")

I set a text box and set the .text property to

txtFacilityID.text = cmbFacilityname.ValueMember

I am setting the txtFacilityID.text so I can see what ValueMember is being returned. Oddly enough, the value being returned is the string "FacilityID", not the actual integer "FacilityID".

It's almost like .NET thinks I want the ValueMember to be the string "FacilityID" instead of the integer "FacilityID".

I used the help and did exactly what it told me to do, but it still isn't working the way I want it to work.

 
Old November 7th, 2003, 04:45 PM
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Ok, I follow you now I think. You are getting the right thing. The combo box is telling you what the ValueMember is (FacilityID).

The Items collection of a windows form combo box contains a collection of objects (unlike the listbox control of a web form) so you can actually access all the members of whatever object is in the collection.

So...

You have a couple options:
1. Cast comboBox.SelectedItem into the right object, then access the desired property.
2. Use comboBox.SelectedValue. This gets the value of the list item member specified by ValueMember.

Sorry it took so long to get an answer, I wasn't clear on what you were trying to do. It's been one of those days.

Peter
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