Why Does My WinForms Listbox Display \'System.Data.DataRowView\' Instead of Actual Values?

Why System.Data.DataRowView Instead of Real Values in WinForms Listbox?

In WinForms development, encountering System.Data.DataRowView instead of actual values in a listbox can be puzzling. Understanding the underlying issue will empower you to resolve this problem efficiently.

In the provided code snippet:

<code class="csharp">MySqlDataAdapter dAdapter = new MySqlDataAdapter(sqlStr, myConn);
DataTable dTable = new DataTable();
dAdapter.Fill(dTable);
dAdapter.Dispose();
lstNames.DisplayMember = "NameAndScore";
lstNames.DataSource = dTable;</code>

The code appears correct, as the DataTable is filled through a MySqlDataAdapter and then assigned as the data source for the ListBox control. However, the DisplayMember property is set to "NameAndScore", which is a column alias.

When binding data to a listbox, the DisplayMember property specifies the column that provides the text displayed in the list. By setting it to the alias "NameAndScore", you instruct the listbox to display the string System.Data.DataRowView instead of the actual data, because the underlying data structure is a DataRowView representation of the table.

Solution:

To correct this issue and display the actual values from the database:

• Set the DisplayMember to the actual column name:

<code class="csharp">lstNames.DisplayMember = "Score";</code>

• Retrieve the specific values using the DataRowView representation:

<code class="csharp">DataRowView drv = (DataRowView)lstNames.SelectedItem;
String valueOfItem = drv["NameAndScore"].ToString();</code>

This approach allows you to access individual values associated with the selected item, enabling you to work with the underlying data as needed.

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