I'm sure everyone has had enough of my posts but these datagridviews are giving me so much hassle! I have three of them that are used for data collection to do a filtered search of a database. each one has two columns left is a list of manufactures, suppliers or categories the right is checkbox column and I have the code below that is used to form a string of all the entries on the left who were checked in the right column. but it fails and says "object reference not set to an instance of an object"
//manufacturer filter used as example
if (checkBoxManufacturerFilter.Checked == true) //this combobox isn't in the table its just to indicate weather this filter should be applyed or not
{
if (FirstFilter == false)
{
FilteredSearchQuery = FilteredSearchQuery + "and ";
}
string ManufacturerList = string.Empty;
foreach (DataGridViewRow row in DGVmanufacturerFilter.Rows)
{
if ((bool)row.Cells[1].Value == true)
{
ManufacturerList = ManufacturerList + "," + (string)row.Cells[0].Value;
}
}
if (ManufacturerList.Length > 0)
{
if (ManufacturerList.Substring(0, 1) == ",")
{
ManufacturerList = ManufacturerList.Substring(1);
}
}
ManufacturerList = "(" + ManufacturerList + ")";
string ManufacturerFilterClause = "manufacturer in " + ManufacturerList + " ";
FilteredSearchQuery = FilteredSearchQuery + ManufacturerFilterClause;
if (FirstFilter == true)
{
FirstFilter = false;
}
}