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Editorial Team
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Asked: 2026-06-03T06:15:42+00:00

I’ve found several topics with a similar issue but the contents seemed slightly different

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I’ve found several topics with a similar issue but the contents seemed slightly different and I have not been able to solve my problem as a result.

In my application I have DataTable that contains 4 columns:

  • UInt16
  • UInt64
  • UInt64
  • A self defined enumeration type consisting of 2 values.

In order to display the values of this DataTable I created a DataGridView and set this table as the datasource. So far so good. I wanted the enumeration field column to contain comboboxes instead and ran into the DataGridViewComboBoxColumn type. I had some issues getting it to work but eventualy ended up using the following approach:

// Create the 4 datarows

// Add the datarows to the data table

// Set the data table as the data source for the data grid view

// Remove the column that represents the enumeration

// Add a DataGridViewComboBoxColumn to the DataGridView as replacement

I have created the DataGridViewComboBoxColumn as follows:

DataGridViewComboBoxColumn cb = new DataGridViewComboBoxColumn();
cb.HeaderText   = "My header text";
cb.ValueType    = typeof(MyEnumType);
cb.DataSource   = Enum.GetValues(typeof(MyEnumType));
cb.FlatStyle    = FlatStyle.System;
cb.Name         = "Name"; //Same name as the DataColumn and the now deleted DataGridViewColumn
cb.DataPropertyName = "Name"; //Same name as the DataColumn and the now deleted DataGridViewColumn
cb.DisplayStyle     = DataGridViewComboBoxDisplayStyle.Nothing;

dataGridView.Columns.Add(cb);

Once my application starts I read in data from a text file that get placed into a structure with fields of the 4 datatypes mentioned above. I then add these fields to the DataTable as follows:

DataRow row = dataTable.NewRow();
row["Name of the UInt16 column"]    = mystruct.theUInt16;
row["Name of the UInt64 column"]    = mystruct.theUInt64;
row["Name of the UInt64 column"]    = mystruct.theUInt64_2;
row["Name of the enum column"]      = mystruct.theEnumValue;               
dataTable.Rows.Add(row);

on startup the DataError event gets called repeatedly. The contents of the cells do get filled properly however. (I see this after clicking away the error a couple of times) Disabling the DataError event (assigning an empty handler for example) is something I prefer to not do.

I think there is some sort of type mismatch somehow. (maybe the enum type and a string for display?) This is however only a guess. The dataTable column and the datagridview column both have the type set to the enumeration.

I hope someone can point me in the right direction.

Thanks in advance!

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1 Answer

  1. Editorial Team

    I have managed to find a workaround that suits my needs. The approach is still the same as in my original post. I made gave the enum in the DataTable the name “colMyEnumTypeTable” and the datatype is string instead of MyEnumType. Then I removed this column and added the DataGridViewComboBoxColumn named “colMyEnumType” with DataPropertyName “colMyEnumTypeTable” and also being of type string. I then convert the enumeration values to string when adding them to the data table, and when extracting I use Enum.Parse to retrieve the enum value again. No more DataError calls are made.

    -edit-
    I gave the DataTable and DataGridViewComboBoxColumn different names to ensure that wasn’t causing problems. I have now changed them back so they have the same name and it still works.

    -edit2-
    And instead of setting the DataSource property for the comboboxcolumn I added the enum values by adding them to the Items property. (after converted to string)

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