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Multicolumn Combobox Lookup Error

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MultiColumn ComboBox

This is a migrated thread and some comments may be shown as answers.

Edwin asked on 20 May 2009, 10:46 AM

Hi,

I would like to use the multicolumn combobox as a lookup combobox. If I setup the mc combo with the same properties as a normal combobox it gives me the following message.
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RadGridView Default Error Dialog
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The following exception occurred in the RadGridView:

System.Data.ReadOnlyException: Column 'BusID' is read only.
   at System.Data.DataRow.set_Item(DataColumn column, Object value)
   at System.Data.DataRowView.SetColumnValue(DataColumn column, Object value)
   at System.Data.DataColumnPropertyDescriptor.SetValue(Object component, Object value)
   at Telerik.WinControls.Data.DataAccessComponent.set_Item(GridViewRowInfo row, GridViewDataColumn column, Object value)
To replace this default dialog please handle the DataError event.
---------------------------
OK
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These are the (in my opinion) relevant designer.cs entry's

    
            // cmbJourneyBus(multicolumncombobox)  
        
            this.cmbJourneyBus.DataBindings.Add(new System.Windows.Forms.Binding("SelectedValue", this.journeyBindingSource, "BusID", true));  
        
            this.cmbJourneyBus.DataSource = this.busBindingSource;  
        
            this.cmbJourneyBus.DisplayMember = "BusNumber";  
        
            this.cmbJourneyBus.ValueMember = "BusID";  
        
            // radComboBox1 (standard radcombobox)  
        
            this.radComboBox1.DataBindings.Add(new System.Windows.Forms.Binding("SelectedValue", this.journeyBindingSource, "BusID", true));  
        
            this.radComboBox1.DataSource = this.busBindingSource;  
        
            this.radComboBox1.DisplayMember = "BusNumber";  
        
            this.radComboBox1.ValueMember = "BusID";

Am I doing something wrong or is this a bug?

Kind regards,

Edwin Dirkzwager
CIP Software BV
The Netherlands.

5 Answers, 1 is accepted

answered on 22 May 2009, 08:30 PM

Hi Julian,

BusID is readonly because it is an identity field (autonumber). Wat I do not understand is why the grid complains about this field. The entire grid is readonly so it (in my opinion) should not matter. The normal combobox does not give me this problem.

Further more: handling the dataerror event is not a solution. I do not want to customize the error message, the error should not occur in the first place.

Removing the ID value from the grid might be a solution in some cases (you may want to show the ID value for certain tables). But this raises another question for which I have posted a support ticket.

Kind regards,

Edwin Dirkzwager
CIP Software BV
The Netherlands.