ComboBoxEdit.set_SelectedItem performs incorrect equality tests

Hello,

Further investigation has not proved the problem. Here is the implementation of the ComboBoxItemCollection.Contains method:

	
[C#]
public virtual bool Contains(object item) {
    return IndexOf(item) != -1;
}

So, there is no problem here.

Below is our code for the ComboBoxEdit.SelectedIndex property:

	
[C#]
public virtual int SelectedIndex {
    get { return Properties.Items.IndexOf(SelectedItem); }
    set {
        if(value < 0 || value >= Properties.Items.Count)
            SelectedItem = null;
        else
            SelectedItem = Properties.Items[value];
    }
}

Both members are virtual and therefore can be overridden in descendants, if you still want to change their behavior.

Thanks,
Nick
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I think you misunderstood what I wrote. It was a complicated explanation, but maybe object identity is an inherently complicated topic. :-)

You pasted source code for Contains() and SelectedIndex, but the problem I reported is in the ComboBoxEdit.SelectedItem property.

Suppose we have a class like this:

  class CExampleItem {
    public string Filename;

    [...]

    public override string ToString() {
      return Filename;
    }

    // CExampleItem instances are considered equivalent if their filenames are the same
    public override bool Equals(object obj) {
      return Filename == ((CExampleItem)obj).Filename;
    }
  }

Now suppose several CExampleItem instances have been added to the ComboBoxEdit.Properties.Items list, and then this happens:

  CExampleItem notInList = new CExampleItem();
  notInList.Filename = "Example.dat";
  
  MyComboBoxEdit.SelectedItem = notInList;

Let's suppose there's a different CExampleItem in the list whose filename is also "Example.dat". Contains() will compare them using Equals() and return true, but the resulting EditValue is the notInList value:

    if (Properties.Items.Contains(value)) EditValue = value;

By contrast, your ListBoxControl uses this approach, which will correctly set EditValue to the matching item in the list:

    int index = Properties.Items.IndexOf(value);
    if (index != -1) SelectedIndex = index;

Hello,

> if (Properties.Items.Contains(value)) EditValue = value;
I cannot find the above code line in our ComboBoxEdit class. Could you please describe your requirements in greater detail?

Thanks,
Nick
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Hi Nick,

This is the DLL:

DevExpress.XtraEditors.v9.2, Version=9.2.6.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a

This is the class:

DevExpress.XtraEditors.ComboBoxEdit

This is the method:

public virtual object SelectedItem {
  get { }
  set { ... } <----- this one
}

Let me know if you need anything else. Thanks!