ComboBox Data Binding and Case Sensitivity

Provided by Dave Juth, Senior System Architect

The ValueMember property of the Combo Box allows users to set the binding column of the combo box. The .ValueMember property of a ComboBox is case sensitive. If you mis-type the column name, or type the correct column name with the wrong case for this property your code will throw an exception, "Could not bind to the new value member." Without knowing that this is a likely cause of the exception, this can be very difficult to track down.  

An example: if the value column is named "EmployeeId" and you use "EmployeeID," this will trigger the error:

comboBoxEmployee.DataSource = dtEmployee;

comboBoxEmployee.DisplayMember = "Name";

comboBoxEmployee.ValueMember = "EmployeeID";