How can I fix this error:
Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index
In this code:
dataGridView1.AllowUserToAddRows = false;
dataGridView1.Columns.Add("ID", "ID");
dataGridView1.Columns.Add("Firstname", "Firstname");
dataGridView1.Columns.Add("MI", "MI");
dataGridView1.Columns.Add("Lastname", "Lastname");
dataGridView1.Columns.Add("Username", "Username");
dataGridView1.Columns.Add("Rights", "Rights");
c.Open();
OleDbCommand cmd = new OleDbCommand();
cmd.Connection = c;
cmd.CommandText = "SELECT * From Account";
OleDbDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells["ID"].Value = reader[0].ToString();
dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells["Firstname"].Value = reader[1].ToString();
dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells["MI"].Value = reader[2].ToString();
dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells["Lastname"].Value = reader[3].ToString();
dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells["Username"].Value = reader[7].ToString();
dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells["Rights"].Value = reader[9].ToString();
}
c.Close();
You'll get the Indexerror: list index out of range error when you try and access an item using a value that is out of the index range of the list and does not exist. This is quite common when you try to access the last item of a list, or the first one if you're using negative indexing.
The Python "IndexError: list assignment index out of range" occurs when we try to assign a value at an index that doesn't exist in the list. To solve the error, use the append() method to add an item to the end of the list, e.g. my_list.
We can resolve this by simply changing the operator a less than symbol, < . This prevents the loop from looping over the index from going out of range.
Are you trying to display data from database to datagridview
? Why not use databind
?
See my sample code:
string connStr = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=the directory or the path of your database";
string query = "SELECT * From Table Name";
using (OleDbConnection conn = new OleDbConnection(connStr))
{
using (OleDbDataAdapter adapter = new OleDbDataAdapter(query, conn))
{
DataSet ds = new DataSet();
adapter.Fill(ds);
dataGridView1.DataSource = ds.Tables[0];
}
conn.Close();
}
The Rows collection has an 'Add' method that takes an object array. It is definitely a simpler and more straightforward approach that the code sample in your question:
http://msdn.microsoft.com/en-us/library/fbs04kbx.aspx
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