private void btnDelete_Click(object sender, EventArgs e)
{
// get the key of the current product in the data grid view
int rowNum = productDataGridView.CurrentCell.RowIndex; // index of the current row
string prodCode = productDataGridView["dataGridViewTextBoxColumn1", rowNum].Value.ToString(); // Column for ProductCode
DialogResult answer = MessageBox.Show("Are you sure you want to delete " + prodCode + "?", "Confirm", MessageBoxButtons.OKCancel);
if (answer == DialogResult.OK)
{
using (ProductsDataContext dbContext = new ProductsDataContext())
{
try
{
Product currentProduct = (from p in dbContext.Products
where p.ProductCode == prodCode
select p).Single();
//MessageBox.Show("Testing concurrency: update or delete current record from SSMS and click OK");
dbContext.Products.DeleteOnSubmit(currentProduct);
dbContext.SubmitChanges();
RefreshGridView();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
}
}
}
private void btnModify_Click(object sender, EventArgs e)
{
// get the key of the current product in the data grid view
int rowNum = productDataGridView.CurrentCell.RowIndex; // index of the current row
string prodCode = productDataGridView["dataGridViewTextBoxColumn1", rowNum].Value.ToString(); // Column for ProductCode
Product currentProduct;
using (ProductsDataContext dbContext = new ProductsDataContext())
{
currentProduct = (from p in dbContext.Products
where p.ProductCode == prodCode
select p).Single();
}
frmAddModifyProduct secondForm = new frmAddModifyProduct();
secondForm.isAdd = false; // it Modify
secondForm.currentProduct = currentProduct;
DialogResult result = secondForm.ShowDialog(); // display second form modal
if (result == DialogResult.OK || result == DialogResult.Retry) // successful update or concurrency exception
{
RefreshGridView();
}
}
private void Form1_Load(object sender, EventArgs e)
{
using (ProductsDataContext dbContext = new ProductsDataContext())
{
productDataGridView.DataSource = dbContext.Products; // entire table - no need for LINQ query
//productDataGridView.DataSource = from prod in dbContext.Products
// orderby prod.Description
// select prod;
}
}
private bool IsUniqueCode(TextBox productCodeTextBox)
{
Product prod = null;
using (ProductsDataContext dbContext = new ProductsDataContext())
{
prod = (from p in dbContext.Products
where p.ProductCode == productCodeTextBox.Text
select p).SingleOrDefault();
//dbContext.Products.Single(p => p.ProductCode == productCodeTextBox.Text);
if (prod != null) // there is another product with same code
{
MessageBox.Show("Product code must be unique", "Entry Error");
return(false);
}
else
{
return(true);
}
}
}
private void btnSave_Click(object sender, EventArgs e)
{
if (isAdd)
{
if (Validator.IsPresent(productCodeTextBox) &&
Validator.IsCorrectLength(productCodeTextBox, 10) &&
IsUniqueCode(productCodeTextBox) && // coded below in this form
Validator.IsPresent(descriptionTextBox) &&
Validator.IsCorrectLength(descriptionTextBox, 50) &&
Validator.IsPresent(unitPriceTextBox) &&
Validator.IsDecimal(unitPriceTextBox) &&
Validator.IsNonNegativeDecimal(unitPriceTextBox) &&
Validator.IsPresent(onHandQuantityTextBox) &&
Validator.IsInt32(onHandQuantityTextBox) &&
Validator.IsNonNegativeInt(onHandQuantityTextBox)
)
// replace with data validation: all fields provided, code unique,
// price and quantity appropriate numeric type and non-negative
{
Product newProduct = new Product // create product using provided data
{
ProductCode = productCodeTextBox.Text,
Description = descriptionTextBox.Text,
UnitPrice = Convert.ToDecimal(unitPriceTextBox.Text),
OnHandQuantity = Convert.ToInt32(onHandQuantityTextBox.Text)
};
using (ProductsDataContext dbContext = new ProductsDataContext())
{
// insert through data context object from the main form
dbContext.Products.InsertOnSubmit(newProduct);
dbContext.SubmitChanges(); // submit to the database
}
DialogResult = DialogResult.OK;
}
else // validation failed
{
DialogResult = DialogResult.Cancel;
}
}
else // it is Modify
{
if (Validator.IsPresent(descriptionTextBox) &&
Validator.IsCorrectLength(descriptionTextBox, 50) &&
Validator.IsPresent(unitPriceTextBox) &&
Validator.IsDecimal(unitPriceTextBox) &&
Validator.IsNonNegativeDecimal(unitPriceTextBox) &&
Validator.IsPresent(onHandQuantityTextBox) &&
Validator.IsInt32(onHandQuantityTextBox) &&
Validator.IsNonNegativeInt(onHandQuantityTextBox)
)
{
try
{
using (ProductsDataContext dbContext = new ProductsDataContext())
{
// get the product with Code from the current text box
Product prod = dbContext.Products.Single(p => p.ProductCode == productCodeTextBox.Text);
//MessageBox.Show("Testing concurrency: update or delete current record from SSMS and click OK");
if (prod != null)
{
// make changes by copying values from text boxes
prod.Description = descriptionTextBox.Text;
prod.UnitPrice = Convert.ToDecimal(unitPriceTextBox.Text);
prod.OnHandQuantity = Convert.ToInt32(onHandQuantityTextBox.Text);
// submit changes
dbContext.SubmitChanges();
DialogResult = DialogResult.OK;
}
}
}
catch (ChangeConflictException)
{
MessageBox.Show("Another user changed or deleted the current record", "Concurrency Exception");
DialogResult = DialogResult.Retry;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, ex.GetType().ToString());
}
}
else // validation failed
{
DialogResult = DialogResult.Cancel;
}
}
}
private void RefreshGridView()
{
ProductsDataContext dbContext = new ProductsDataContext();
productDataGridView.DataSource = dbContext.Products;
}
