[c#] Index was out of range. Must be non-negative and less than the size of the collection parameter name:index

I'm trying to add data as one by one row to a datagridview here is my code and it says:

"Index was out of range. Must be non-negative and less than the size of the collection parameter name:index"

What does this mean? What is the problem in my code?

String Sqlstr2 = "select ItemName from Item where ItemID = '" + tbItemID.Text + "'";
db.DataRead(Sqlstr2);
string ItemName = db.dr["ItemName"].ToString(); 

DataGridView dataGridView1 = new DataGridView();

dataGridView1.Columns[0].Name = "ItemID";
dataGridView1.Columns[1].Name = "ItemName";
dataGridView1.Columns[2].Name = "Qty";
dataGridView1.Columns[3].Name = "UnitPrice";
dataGridView1.Columns[4].Name = "Amount";

string firstColum = tbItemID.Text;
string secondColum = ItemName;
string thirdColum = tbQuantity.Text;
string fourthColum = Convert.ToString(UnitPrice);
string fifthColum = Convert.ToString(sum);

string[] row = new string[]{ firstColum, secondColum, thirdColum, fourthColum, fifthColum };
dataGridView1.Rows.Add(row);

This error is caused when you have enabled paging in Grid view. If you want to delete a record from grid then you have to do something like this.

int index = Convert.ToInt32(e.CommandArgument);
int i = index % 20;
// Here 20 is my GridView's Page Size.
GridViewRow row = gvMainGrid.Rows[i];
int id = Convert.ToInt32(gvMainGrid.DataKeys[i].Value);
new GetData().DeleteRecord(id);
GridView1.DataSource = RefreshGrid();
GridView1.DataBind();

Hope this answers the question.

dataGridView1.Columns is probably of a length less than 5. Accessing dataGridView1.Columns[4] then will be outside the list.

The error says "The index is out of range". That means you were trying to index an object with a value that was not valid. If you have two books, and I ask you to give me your third book, you will look at me funny. This is the computer looking at you funny. You said - "create a collection". So it did. But initially the collection is empty: not only is there nothing in it - it has no space to hold anything. "It has no hands".

Then you said "the first element of the collection is now 'ItemID'". And the computer says "I never was asked to create space for a 'first item'." I have no hands to hold this item you are giving me.

In terms of your code, you created a view, but never specified the size. You need a

dataGridView1.ColumnCount = 5;

Before trying to access any columns. Modify

DataGridView dataGridView1 = new DataGridView();

dataGridView1.Columns[0].Name = "ItemID";

to

DataGridView dataGridView1 = new DataGridView();
dataGridView1.ColumnCount = 5;
dataGridView1.Columns[0].Name = "ItemID";

See http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.columncount.aspx

what this means ? is there any problem in my code

It means that you are accessing a location or index which is not present in collection.

To find this, Make sure your Gridview has 5 columns as you are using it's 5th column by this line

dataGridView1.Columns[4].Name = "Amount";

Here is the image which shows the elements of an array. So if your gridview has less column then the (index + 1) by which you are accessing it, then this exception arises.