DataGrid not showing the values it is invisible in WPF

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C#

Visual-Studio

MySQL

VS2010

Hi,

I have some value in categorymaster table when i execute below code the data is filling to datagrid but the value is not visible.

This is my code

MySqlConnection con = new MySqlConnection(GlobalClass._ConStr);
con.Open();
string sql = string.Format("select * from categorymaster");
MySqlDataAdapter adp = new MySqlDataAdapter(sql, con);
DataSet ds = new DataSet();
adp.Fill(ds, "emp");
con.Close();
DepartmentGridView.ItemsSource = ds.Tables[0].DefaultView;
DepartmentGridView.SelectedIndex = -1;