Develop Reference

Can't get the total row count

I have a table which has 3 columns and each column has 5 rows.Now I wanna get those total numbers of rows in c# to create that number of labels dynamically as well as get the rows value for labels name.Similarly, creates same numbers of the textbox as well.Then in the runtime, i wanted to submit the value to the database by this textbox.
Note: here, if I increase the rows of the table,then the label and textbox will be increased automatically/dynamically as well as submitting value through textbox will perfectly work.
But , all I have done is only getting count value 1 , I just tried a lot but not getting the total count value which is actually 5 .
here, is my code...
private void Form1_Load(object sender, EventArgs e)
{
string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
//string cmText = "select ProductId,ProductName,UnitPrice from tblProductInventory";
string cmText = "Select Count(ProductId) from tblProductInventory";
SqlCommand cmd = new SqlCommand(cmText, con);
con.Open();
using (SqlDataReader rdr = cmd.ExecuteReader())
{
int count = rdr.FieldCount;
while (rdr.Read())
{
//System.Windows.Forms.Label MyLabel;
{
int y = 50;
Label myLabel = new Label();
for (int i = 0; i < count; i++)
{
myLabel = new Label();
myLabel.Location = new Point(88, y);
myLabel.Name = "txtVWReadings" + i.ToString();
myLabel.Size = new Size(173, 20);
myLabel.TabIndex = i;
myLabel.Visible = true;
myLabel.Text = rdr[i].ToString();
y += 25;
this.Controls.Add(myLabel);
}
}
}
}
}
}
And I got this output.

The issue seems that you are using query as count but you want the values of the field. So you can probably change it to
string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
//string cmText = "select ProductId,ProductName,UnitPrice from tblProductInventory";
string cmText = "Select Count(ProductId) from tblProductInventory";
SqlCommand cmd = new SqlCommand(cmText, con);
con.Open();
Int32 count = (Int32) cmd.ExecuteScalar();
int i = 1;
cmText = "select ProductId,ProductName,UnitPrice from tblProductInventory";
SqlCommand cmd1 = new SqlCommand(cmText, con);
using (SqlDataReader rdr = cmd1.ExecuteReader())
{
int y = 50;
Label myLabel = new Label();
TextBox MyTxt = New TextBox();
while (rdr.Read())
{
myLabel = new Label();
myLabel.Location = new Point(88, y);
myLabel.Name = "txtVWReadings" + i.ToString();
myLabel.Size = new Size(173, 20);
myLabel.TabIndex = i;
myLabel.Visible = true;
myLabel.Text = rdr[1].ToString(); //Since you want ProductName here
y += 25;
this.Controls.Add(myLabel);
//Same Way Just include the TextBox
//After all Position of TextBox
MyTxt.Text = rdr[2].ToString(); // I believe you need UnitPrice of the ProductName
i++;
}
}
}

Count(columname) :
Will count only the NOT NULL values in that column.
Count(*) :
Will count the number of records in that table.
So I guess you have some NULL values in ProductId column. Change it to
Select Count(*) from tblProductInventory

AutoGenrate the code

protected void Button1_Click(object sender, EventArgs e)
{
string cs = ConfigurationManager.ConnectionStrings["Dum01"].ConnectionString;
using (var scon = new SqlConnection(cs))
{
string codevalue = TextBox1.Text.Substring(0, 1);
var query = "SELECT MAX(CODE) AS TCODE FROM AgentMast WHERE LEFT(CODE,1)= #SearchText";
using (var cmd = new SqlCommand(query, scon))
{
cmd.Parameters.AddWithValue("#SearchText",codevalue);
cmd.CommandType = CommandType.Text;
cmd.Connection = scon;
scon.Open();
using (SqlDataReader sdr = cmd.ExecuteReader())
{
while (sdr.Read())
{
TextBox2.Text= sdr["TCODE"].ToString();
}
string codewithnumber = TextBox2.Text.Substring(1, 4);
Label2.Text = codewithnumber;
Label1.Text = (int.Parse(Label2.Text) + 1).ToString();
string firstchar=TextBox2.Text.Substring(0,1);
Label3.Text = firstchar + Label1.Text+"A" ;
}
scon.Close();
}
}
}
When in the textbox some text is entered then according to the first letter it selects the max code from AgentMast table. When I get the max code then I need to increment by one. For example if code found Z0001A then on next insert it should be Z0002A. 'A' is fixed for the agent table and also when TCODE is not found then I need to create new code with first character of textbox text and then 0001 and then fix character 'A'. How to solve? Thanks in Advance.

Try this:
oldCode = sdr["TCODE"].ToString();
if (string.IsNullOrEmpty(oldCode))
{
newCode = codevalue + "0001A";
}
else
{
int newIncrement = Convert.ToInt32(oldCode.Substring(1, 4)) + 1;
newCode = codevalue + newIncrement.ToString().PadLeft(4, '0') + oldCode.Substring(5, 1);
}

Updating DATAGRID row to save to SQL

Hi Guys I am trying to understand how to save and edited row to the database
private void BudgetGrid_RowEditEnding(object sender,
DataGridRowEditEndingEventArgs e)
{
SqlCommand gridcmd = new SqlCommand();
SqlConnection rwConn = null;
rwConn = new SqlConnection("server=localhost;" +
"Trusted_Connection=yes;" + "database=Production; " + "connection
timeout=30");
gridcmd.Connection = rwConn;
rwConn.Open();
//gridcmd.CommandText =
//"SELECT Id, Name, Quantity, Rate, Time FROM Budget";
gridcmd.CommandText =
"UPDATE Budget SET Id = #id, Name = #Name, " +
"Quantity = #Qty, Rate = #Rte WHERE Time = #Time";
SqlDataAdapter gridda = new SqlDataAdapter(gridcmd);
string strId = "#id".ToString();
int intID;
bool bintID = Int32.TryParse(strId, out intID);
string strName = "#Name".ToString();
string strQty = "#Qty".ToString();
int intQty;
bool bintQty = Int32.TryParse(strQty, out intQty);
string strRte = "#Rte".ToString();
int intRte;
bool bintRte = Int32.TryParse(strRte, out intRte);
string strTime = "#Time".ToString();
gridda.SelectCommand.Parameters.Add(
new SqlParameter("#id", SqlDbType.Int));
gridda.SelectCommand.Parameters["#id"].SqlValue = intID;
gridda.SelectCommand.Parameters.Add(
new SqlParameter("#Name", SqlDbType.VarChar));
gridda.SelectCommand.Parameters["#Name"].SqlValue = strName;
gridda.SelectCommand.Parameters.Add(
new SqlParameter("#Qty", SqlDbType.Int));
gridda.SelectCommand.Parameters["#Qty"].SqlValue = strQty;
gridda.SelectCommand.Parameters.Add(
new SqlParameter("#Rte", SqlDbType.Int));
gridda.SelectCommand.Parameters["#Rte"].SqlValue = strRte;
gridda.SelectCommand.Parameters.Add(
new SqlParameter("#Time", SqlDbType.VarChar));
gridda.SelectCommand.Parameters["#Time"].SqlValue = strTime;
DataTable griddt = new DataTable("Budget");
gridda.Fill(griddt);
gridda.UpdateCommand =
new SqlCommandBuilder(gridda).GetUpdateCommand();
BudgetGrid.ItemsSource = griddt.DefaultView;
gridda.Update(griddt);
rwConn.Close();
}
it displays fine. I can edit its but when I click on the other tab it does not update it goes back to the original data.
Most of the code I have been going through its either out dated.. or not what I am looking for.
so here is the database
and here is the app
so basically if i hit tab to the next row. under the event BudgetGrid_RowEditEnding it should update the database.. but now its not.

Just copy below codes. I've created all the thing of you and tested successfully. Rather than the first way, I tried to let you go more popular way. Therefore, it took me time to adopt..
Hope this helps you !
SqlDataAdapter da;
DataTable dt;
private void Window_Loaded(object sender, RoutedEventArgs e)
{
SqlConnection Conn = new SqlConnection();
Conn.ConnectionString = yourConnectionString;
Conn.Open();
SqlCommand gridcomm = new SqlCommand();
gridcomm.Connection = Conn;
gridcomm.CommandText = "SELECT Id, Name, Quantity, Rate, Time FROM Budget";
da = new SqlDataAdapter(gridcomm);
SqlDataReader gridreader = gridcomm.ExecuteReader();
while (gridreader.Read())
{
}
gridreader.Close();
dt= new DataTable("Budget");
da.Fill(dt);
dataGrid_Budget.ItemsSource = dt.DefaultView;
Conn.Close();
}
private void dataGrid_Budget_RowEditEnding(object sender, System.Windows.Controls.DataGridRowEditEndingEventArgs e)
{
DataGridRow editedrow = e.Row;
int row_index = (DataGrid)sender).ItemContainerGenerator.IndexFromContainer(editedrow);
for (int k=0;k< 5;k++)
{
DataGridCell cell = GetCell(row_index, k);
TextBlock tb = cell.Content as TextBlock;
if (k==1)
{
dt.Rows[row_index][k] = tb.Text;
}
else if (k == 4)
{
if (tb.Text != "")
{
dt.Rows[row_index][k] = Convert.ToDateTime(tb.Text);
}
}
else
{
dt.Rows[row_index][k] = Convert.ToInt32(tb.Text);
}
}
da.UpdateCommand = new SqlCommandBuilder(da).GetUpdateCommand();
da.Update(dt);
}
public DataGridCell GetCell(int row, int column)
{
DataGridRow rowContainer = GetRow(row);
if (rowContainer != null)
{
DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
if (cell == null)
{
dataGrid_Budget.ScrollIntoView(rowContainer, dataGrid_Budget.Columns[column]);
cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
}
return cell;
}
return null;
}
public DataGridRow GetRow(int index)
{
DataGridRow row = (DataGridRow)dataGrid_Budget.ItemContainerGenerator.ContainerFromIndex(index);
if (row == null)
{
dataGrid_Budget.UpdateLayout();
dataGrid_Budget.ScrollIntoView(dataGrid_Budget.Items[index]);
row = (DataGridRow)dataGrid_Budget.ItemContainerGenerator.ContainerFromIndex(index);
}
return row;
}
public static T GetVisualChild<T>(Visual parent) where T : Visual
{
T child = default(T);
int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < numVisuals; i++)
{
Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
child = v as T;
if (child == null)
{
child = GetVisualChild<T>(v);
}
if (child != null)
{
break;
}
}
return child;
}

Your SQL syntax has to be corrected like,
SqlCommand update_comm = new SqlCommand();
update_comm.Connection = Conn;
update_comm.CommandText = "UPDATE Budget SET id= #u_id, Name= #u_name WHERE person= #psn";
var update_da = new SqlDataAdapter(update_comm);
update_da.SelectCommand.Parameters.Add(new SqlParameter("#u_id", SqlDbType.Int));
update_da.SelectCommand.Parameters["#u_id"].Value = yourintvalue;
update_da.SelectCommand.Parameters.Add(new SqlParameter("#u_name", SqlDbType.NVarChar));
update_da.SelectCommand.Parameters["#u_name"].Value = yourstringvalue;
update_da.SelectCommand.Parameters.Add(new SqlParameter("#psn", SqlDbType.NVarChar));
update_da.SelectCommand.Parameters["#psn"].Value = yourstringvalue;
var update_ds = new DataSet();
update_da.Fill(update_ds);
'UPDATE' should be used with 'SET' together.
And if you want to update the actual SQL database with the value of edited rows of DataGrid, please try this.
da.UpdateCommand = new SqlCommandBuilder(da).GetUpdateCommand();
da.Update(griddt);

SqlConnection uniConn = null;
SqlCommand cmd = null;
SqlDataAdapter sda = null;
DataTable dt = new DataTable();
uniConn = new SqlConnection(
"server=localhost;" + "Trusted_Connection=yes;" +
"database=Production; " + "connection timeout=30");
cmd = new SqlCommand("UPDATE Budget(id, Name, Quantity, Rate, Time)",
uniConn);
uniConn.Open();
sda = new SqlDataAdapter(cmd);
sda.Fill(dt);
BudgetGrid.ItemsSource = dt.DefaultView;
uniConn.Close();
Did you forget to close the connection?

Keep stuck at the reading the data from database

I would like to minus the data from the database with the value that I give when I run the program. Everything works, but I keep stuck at the newVal. I already did it like this, but the newVal keep appear 0 (because I declared decimal newVal = 0, but on this question, I just used decimal newVal;). Two more problems: if I move the newVal = ... to the top, it is useless, because one of the calculations in the newVal is reading data from the database (since I want database minus with the new value given when i run the program, required dReader = cmd.ExecuteReader();), but if I put the newVal at the bottom after reading data, it is useless as well, because I set the Quantity = ? and the value of ? is newVal.. Well, here is the code:
private void AddObjects(object sender, EventArgs e, Form theForm)
{
button1.Visible = true;
textBoxQuantityContainer = new List<NumericUpDown>();
textBoxCodeContainer = new List<NumericTextBox>();
textBoxDescContainer = new List<TextBox>();
textBoxSubTotalContainer = new List<TextBox>();
textBoxTotalContainer = new List<TextBox>();
textBoxAllTotalContainer = new TextBox();
OleDbDataReader dReader;
OleDbConnection conn = new OleDbConnection(connectionString);
conn.Open();
OleDbCommand cmd = new OleDbCommand("SELECT [Code] FROM [Seranne]", conn);
dReader = cmd.ExecuteReader();
AutoCompleteStringCollection codesCollection = new AutoCompleteStringCollection();
while (dReader.Read())
{
string numString = dReader[0].ToString().PadLeft(4, '0');
codesCollection.Add(numString);
}
dReader.Close();
conn.Close();
if (firstForm.comboBox1.SelectedIndex == 0)
{
label1.Text = "Code:";
label1.Location = new Point(60, 125);
label2.Text = "Welcome to the Selling System.";
label2.Location = new Point(600, 30);
label3.Text = "Quantity:";
label3.Location = new Point(155, 125);
label4.Text = "Description:";
label4.Location = new Point(580, 125);
label5.Text = "Sub Total on Rp:";
label5.Location = new Point(1020, 125);
label6.Text = "Total on Rp:";
label6.Location = new Point(1210, 125);
label7.Text = "Total on Rp:";
label7.Location = new Point(1080, 580);
}
else if (firstForm.comboBox1.SelectedIndex == 1)
{
label1.Text = "Kode:";
label1.Location = new Point(60, 125);
label2.Text = "Selamat datang di Selling System.";
label2.Location = new Point(600, 30);
label3.Text = "Banyaknya:";
label3.Location = new Point(145, 125);
label4.Text = "Keterangan:";
label4.Location = new Point(580, 125);
label5.Text = "Sub Total di Rp:";
label5.Location = new Point(1020, 125);
label6.Text = "Total di Rp:";
label6.Location = new Point(1210, 125);
label7.Text = "Total di Rp:";
label7.Location = new Point(1080, 580);
}
//****TextBox for Code****
for (int y = 0; y <= 16; y++)
{
textBoxCodeContainer.Add(new NumericTextBox());
textBoxCodeContainer[y].Size = new Size(100, 50);
textBoxCodeContainer[y].Location = new Point(25, 150 + (y * 25));
textBoxCodeContainer[y].TextChanged += new System.EventHandler(this.textBox_TextChanged);
textBoxCodeContainer[y].AutoCompleteMode = AutoCompleteMode.Suggest;
textBoxCodeContainer[y].AutoCompleteSource = AutoCompleteSource.CustomSource;
textBoxCodeContainer[y].AutoCompleteCustomSource = codesCollection;
theForm.Controls.Add(textBoxCodeContainer[y]);
}
//****TextBox for Quantity****
for (int y = 0; y <= 16; y++)
{
textBoxQuantityContainer.Add(new NumericUpDown());
textBoxQuantityContainer[y].Size = new Size(100, 50);
textBoxQuantityContainer[y].Location = new Point(125, 150 + (y * 25));
textBoxQuantityContainer[y].TextChanged += new System.EventHandler(this.textBox_TextChanged);
textBoxQuantityContainer[y].Maximum = 1000;
theForm.Controls.Add(textBoxQuantityContainer[y]);
}
//****TextBox for Description****
for (int y = 0; y <= 16; y++)
{
textBoxDescContainer.Add(new TextBox());
textBoxDescContainer[y].Size = new Size(750, 50);
textBoxDescContainer[y].Location = new Point(225, 150 + (y * 25));
theForm.Controls.Add(textBoxDescContainer[y]);
}
//****TextBox for Sub Total****
for (int y = 0; y <= 16; y++)
{
textBoxSubTotalContainer.Add(new TextBox());
textBoxSubTotalContainer[y].Size = new Size(175, 50);
textBoxSubTotalContainer[y].Location = new Point(975, 150 + (y * 25));
theForm.Controls.Add(textBoxSubTotalContainer[y]);
}
//****TextBox for Total****
for (int y = 0; y <= 16; y++)
{
textBoxTotalContainer.Add(new TextBox());
textBoxTotalContainer[y].Size = new Size(175, 50);
textBoxTotalContainer[y].Location = new Point(1150, 150 + (y * 25));
textBoxTotalContainer[y].TextChanged += new System.EventHandler(this.textBox_TextChanged);
theForm.Controls.Add(textBoxTotalContainer[y]);
}
//****TextBox for Total All****
textBoxAllTotalContainer.Size = new Size(175, 50);
textBoxAllTotalContainer.Location = new Point(1150, 575);
textBoxAllTotalContainer.TextChanged += new System.EventHandler(this.textBox_TextChanged);
theForm.Controls.Add(textBoxAllTotalContainer);
}
private void UpdateDatas()
{
int codeValue = 0;
int index = 0;
string query = "SELECT [Quantity], [Description], [Price] FROM [Seranne] WHERE [Code] IN (";
OleDbConnection conn = new OleDbConnection(connectionString);
conn.Open();
if (int.TryParse(this.textBoxCodeContainer[0].Text, out codeValue))
{
query = query + codeValue.ToString();
}
for (int i = 1; i < 17; i++)
{
if (int.TryParse(this.textBoxCodeContainer[i].Text, out codeValue))
{
query = query + "," + codeValue.ToString();
}
}
query = query + ")";
OleDbCommand cmd = new OleDbCommand(query, conn);
OleDbDataReader dReader;
dReader = cmd.ExecuteReader();
while (dReader.Read())
{
if (textBoxCodeContainer[index].TextLength != 0)
{
this.textBoxQuantityContainer[index].Maximum = Convert.ToInt32(dReader["Quantity"].ToString());
this.textBoxDescContainer[index].Text = dReader["Description"].ToString();
this.textBoxSubTotalContainer[index].Text = dReader["Price"].ToString();
}
index += 1;
}
dReader.Close();
conn.Close();
}
private void UpdatePrice()
{
int totalPrice = 0;
int quantity = 0;
int price = 0;
for (int i = 0; i < 17; i++)
{
if (textBoxQuantityContainer[i].Value > 0)
{
quantity = (int)textBoxQuantityContainer[i].Value;
price = Convert.ToInt32(textBoxSubTotalContainer[i].Text);
textBoxTotalContainer[i].Text = (quantity * price).ToString();
}
else
{
textBoxSubTotalContainer[i].Text = "";
textBoxTotalContainer[i].Text = "";
}
}
for (int i = 0; i < 17; i++)
{
if (textBoxTotalContainer[i].TextLength != 0)
{
totalPrice += Convert.ToInt32(textBoxTotalContainer[i].Text);
}
}
textBoxAllTotalContainer.Text = totalPrice.ToString("n2");
}
private void UpdateQuantity()
{
int index = 0;
int codeValue = 0;
decimal newVal;
List<int> integers = new List<int>();
foreach (var tb in textBoxCodeContainer)
{
if (int.TryParse(tb.Text, out codeValue))
{
integers.Add(codeValue);
}
}
string command = "UPDATE [Seranne] SET [Quantity]=? WHERE [Code] IN(" + string.Join(", ", integers) + ")";
OleDbConnection conn = new OleDbConnection(connectionString);
OleDbCommand cmd = new OleDbCommand(command, conn);
cmd.Parameters.Add("Quantity", System.Data.OleDb.OleDbType.Integer);
cmd.Parameters["Quantity"].Value = this.newVal.ToString();
OleDbDataReader dReader;
conn.Open();
dReader = cmd.ExecuteReader();
while (dReader.Read())
{
if (textBoxQuantityContainer[index].Value != 0)
{
newVal = (Convert.ToInt32(dReader["Quantity"].ToString()) -
textBoxQuantityContainer[index].Value);
int numberOfRows = cmd.ExecuteNonQuery();
}
index += 1;
}
if (newVal == 0)
{
System.Media.SoundPlayer sounds = new System.Media.SoundPlayer(#"C:\Windows\Media\Windows Notify.wav");
sounds.Play();
MessageBox.Show("Cannot Update", "Error");
}
else
{
System.Media.SoundPlayer sound = new System.Media.SoundPlayer(#"C:\Windows\Media\Windows Notify.wav");
sound.Play();
MessageBox.Show("Was Updated Successfully", "Success");
}
dReader.Close();
conn.Close();
}
private void textBox_TextChanged(object sender, EventArgs e)
{
UpdateDatas();
UpdatePrice();
}
private void button1_Click(object sender, EventArgs e)
{
UpdateQuantity();
}
Thanks a bunch

Good day, i got several things here:
1) cmd.Parameters["Quantity"].Value = this.newVal.ToString(); conversion to string is not needed here, because the Value is an object. You already defined that it should be handled as integer.
2) Replace the ? within you query to #Quantity, so it will be filled by the query execution.
3) When updating you don't need to execute it as a reader. use the int numberOfRows = cmd.ExecuteNonQuery(); without the loop. It will update all items.
4) You should execute the if (textBoxQuantityContainer[index].Value != 0 && textBoxQuantityContainer[index].Value >=
Convert.ToInt32(dReader["Quantity"].ToString()))
{ when building the integers list, this way you are only updating the right quantities.
If you only want to update certain rows, you'll have to expand your where clause:
cmd.Parameters.Add("MinimumQuantity", System.Data.OleDb.OleDbType.Integer).Value = minimumQuantity;
string command = "UPDATE [Seranne]
SET [Quantity]=#Quantity
WHERE [Code] IN(" + string.Join(", ", integers) + ")
AND [Quantity] > #MinimumQuantity
The higest risk is: You assume that the order and count of the records are the same between your textBoxCodeContainer and the database.
What is the relation between a textbox and a row. How do you know what textbox links to which row?
I could give you a push in the right direction, if you show me some more code (like where/how is textBoxCodeContainer defined)
UPDATE:
I made some code the read and manipulate your database, this is not tested since i don't have any database here.
I would create these classes, 1 is a data class Product and one is a Handler class ProductHandler.
The data class only contains the data (not in presentation format) The data handler knows how to read and write them.
public class Product
{
public int Code { get; set; }
public string Description { get; set; }
public int Quantity { get; set; }
}
public class ProductHandler
{
public ProductHandler(string connectionString)
{
ConnectionString = connectionString;
}
public bool AddProduct(Product product)
{
return AddProducts(new Product[] { product }) > 0;
}
public int AddProducts(IEnumerable<Product> products)
{
int rowsInserted = 0;
using (OleDbConnection conn = new OleDbConnection(ConnectionString))
{
conn.Open();
string query = "INSERT INTO [Seranne] (Code, Description, Quantity) VALUES(#Code, #Description, #Quantity)";
using (OleDbCommand cmd = new OleDbCommand(query, conn))
{
cmd.Parameters.Add("Code", OleDbType.Integer);
cmd.Parameters.Add("Description", OleDbType.VarChar);
cmd.Parameters.Add("Quantity", OleDbType.Integer);
foreach (var product in products)
{
cmd.Parameters["Code"].Value = product.Code;
cmd.Parameters["Description"].Value = product.Description;
cmd.Parameters["Quantity"].Value = product.Quantity;
rowsInserted += cmd.ExecuteNonQuery();
}
}
}
return rowsInserted;
}
public bool UpdateProduct(Product product)
{
return UpdateProducts(new Product[] { product }) > 0;
}
public int UpdateProducts(IEnumerable<Product> products)
{
int rowsUpdated = 0;
using (OleDbConnection conn = new OleDbConnection(ConnectionString))
{
conn.Open();
string query = "UPDATE [Seranne] SET Description = #Description, Quantity = #Quantity WHERE [Code] == #Code)";
using (OleDbCommand cmd = new OleDbCommand(query, conn))
{
cmd.Parameters.Add("Code", OleDbType.Integer);
cmd.Parameters.Add("Description", OleDbType.VarChar);
cmd.Parameters.Add("Quantity", OleDbType.Integer);
foreach (var product in products)
{
cmd.Parameters["Code"].Value = product.Code;
cmd.Parameters["Description"].Value = product.Description;
cmd.Parameters["Quantity"].Value = product.Quantity;
rowsUpdated += cmd.ExecuteNonQuery();
}
}
}
return rowsUpdated;
}
public bool DeleteProduct(Product product)
{
return DeleteProducts(new int[] { productCode }) > 0;
}
public int DeleteProducts(IEnumerable<Product> products)
{
using (OleDbConnection conn = new OleDbConnection(ConnectionString))
{
conn.Open();
string productCodeStr = string.Join(", ", products.Select(item => item.Code));
string query = string.Format("DELETE FROM [Seranne] WHERE [Code] in ({0})", productCodeStr);
using (OleDbCommand cmd = new OleDbCommand(query, conn))
{
int rowsDeleted = cmd.ExecuteNonQuery();
return rowsDeleted;
}
}
}
public IEnumerable<Product> ReadAllProducts()
{
List<Product> result = new List<Product>();
using (OleDbConnection conn = new OleDbConnection(ConnectionString))
{
conn.Open();
using (OleDbCommand cmd = new OleDbCommand("SELECT [Code], [Description], [Quantity] FROM [Seranne]", conn))
using (OleDbDataReader dReader = cmd.ExecuteReader())
while (dReader.Read())
{
Product product = new Product();
product.Code = Convert.ToInt32(dReader["Code"]);
product.Description = Convert.ToString(dReader["Description"]);
product.Quantity = Convert.ToInt32(dReader["Quantity"]);
result.Add(product);
}
}
return result;
}
public string ConnectionString { get; private set; }
}
Some example code:
ProductHandler _productHandler = new ProductHandler("connectionstring here or from config");
public void Example()
{
_productList.Clear();
_productList.AddRange(_productHandler.ReadAllProducts());
// displaying
foreach (var product in _productList)
Trace.WriteLine(string.Format("code: {0}, description: {1}, quantity: {2}", product.Code, product.Description, product.Quantity);
// updating
var selectedProduct = _productList.FirstOrDefault(item => item.Code == 15);
if(selectedProduct!= null)
{
selectedProduct.Quantity = 50;
_productHandler.UpdateProduct(selectedProduct);
}
// deleting
_productHandler.DeleteProducts(_productList.Where(item => item.Quantity < 5));
}
How to link the textboxes to the right product:
I would create a UserControl that contains a Product property and the TextBoxes and handles when textbox_changed events occurs. Those event handlers manipulate the Product instance.
You only generate 16 controls and bind a product to it. When you press a button, you only need to save the changed products.

c# how to set beginInvoke end?

I have code my system to save a temporary image file to a folder from the pictureBox then I have to make sure that the beginInvoke end and code the system to delete the temporary image file of that folder. Anyone know how to do that?
This is my code:
//Image Selection End Point
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
// Do nothing it we're not selecting an area.
if (!RegionSelect) return;
RegionSelect = false;
//Display the original image.
pictureBox1.Image = bmpImage;
// Copy the selected part of the image.
int wid = Math.Abs(x0 - x1);
int hgt = Math.Abs(y0 - y1);
if ((wid < 1) || (hgt < 1)) return;
Bitmap area = new Bitmap(wid, hgt);
using (Graphics g = Graphics.FromImage(area))
{
Rectangle source_rectangle = new Rectangle(Math.Min(x0, x1), Math.Min(y0, y1), wid, hgt);
Rectangle dest_rectangle = new Rectangle(0, 0, wid, hgt);
g.DrawImage(bmpImage, dest_rectangle, source_rectangle, GraphicsUnit.Pixel);
}
// Display the result.
pictureBox3.Image = area;
Bitmap bm = new Bitmap(area);
bm.Save(#"C:\Users\Shen\Desktop\LenzOCR\TempFolder\tempPic.jpeg", System.Drawing.Imaging.ImageFormat.Jpeg);
singleFileInfo = new FileInfo(#"C:\Users\Shen\Desktop\LenzOCR\TempFolder\tempPic.jpeg");
}
private void ScanBT_Click(object sender, EventArgs e)
{
var folder = #"C:\Users\Shen\Desktop\LenzOCR\LenzOCR\WindowsFormsApplication1\ImageFile";
DirectoryInfo directoryInfo;
FileInfo[] files;
directoryInfo = new DirectoryInfo(folder);
files = directoryInfo.GetFiles("*.jpg", SearchOption.AllDirectories);
var processImagesDelegate = new ProcessImagesDelegate(ProcessImages2);
processImagesDelegate.BeginInvoke(files, processImagesDelegate.EndInvoke, null);
}
private void ProcessImages2(FileInfo[] files)
{
var comparableImages = new List<ComparableImage>();
var index = 0x0;
var operationStartTime = DateTime.Now;
foreach (var file in files)
{
if (exit)
{
return;
}
var comparableImage = new ComparableImage(file);
comparableImages.Add(comparableImage);
index++;
}
index = 0;
similarityImagesSorted = new List<SimilarityImages>();
operationStartTime = DateTime.Now;
var fileImage = new ComparableImage(singleFileInfo);
for (var i = 0; i < comparableImages.Count; i++)
{
if (exit)
return;
var destination = comparableImages[i];
var similarity = fileImage.CalculateSimilarity(destination);
var sim = new SimilarityImages(fileImage, destination, similarity);
similarityImagesSorted.Add(sim);
index++;
}
similarityImagesSorted.Sort();
similarityImagesSorted.Reverse();
similarityImages = new BindingList<SimilarityImages>(similarityImagesSorted);
con = new System.Data.SqlClient.SqlConnection();
con.ConnectionString = "Data Source=SHEN-PC\\SQLEXPRESS;Initial Catalog=CharacterImage;Integrated Security=True";
con.Open();
String getImage = "SELECT ImageName, ImagePath FROM CharacterImage WHERE ImageName='" + similarityImages[0].Destination.ToString() + "'";
String getImage1 = "SELECT ImageName, ImagePath FROM CharacterImage WHERE ImageName='" + similarityImages[1].Destination.ToString() + "'";
String getImage2 = "SELECT ImageName, ImagePath FROM CharacterImage WHERE ImageName='" + similarityImages[2].Destination.ToString() + "'";
SqlCommand cmd = new SqlCommand(getImage, con);
SqlDataReader rd = cmd.ExecuteReader();
while (rd.Read())
{
getPath = rd["ImagePath"].ToString();
pictureBox4.Image = Image.FromFile(getPath);
}
rd.Close();
SqlCommand cmd1 = new SqlCommand(getImage1, con);
SqlDataReader rd1 = cmd1.ExecuteReader();
while (rd1.Read())
{
getPath1 = rd1["ImagePath"].ToString();
pictureBox5.Image = Image.FromFile(getPath1);
}
rd1.Close();
SqlCommand cmd2 = new SqlCommand(getImage2, con);
SqlDataReader rd2 = cmd2.ExecuteReader();
while (rd2.Read())
{
getPath2 = rd2["ImagePath"].ToString();
pictureBox6.Image = Image.FromFile(getPath2);
}
con.Close();
}
private void pictureBox4_Click(object sender, EventArgs e)
{
if (pictureBox4.Image == null)
{
MessageBox.Show("Nothing has been scanned yet!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
else
{
con = new System.Data.SqlClient.SqlConnection();
con.ConnectionString = "Data Source=SHEN-PC\\SQLEXPRESS;Initial Catalog=CharacterImage;Integrated Security=True";
con.Open();
String getText = "SELECT ImagePath, Character FROM CharacterImage WHERE ImagePath='" + getPath + "'";
SqlCommand cmd = new SqlCommand(getText, con);
SqlDataReader rd = cmd.ExecuteReader();
while (rd.Read())
{
for (int i = 0; i < 1; i++)
{
String imageChar = rd["Character"].ToString();
Action showText = () => ocrTB.AppendText(imageChar);
ocrTB.Invoke(showText);
}
}
rd.Close();
}
}

BeginInvoke returns you with an IAsyncResult which you can use to wait for the operation to complete:
IAsyncResult result = processImagesDelegate.BeginInvoke(files, processImagesDelegate.EndInvoke, null);
You can then check whether the operation completed using the result.IsCompleted property, or you can wait on the WaitHandle returned from result.AsyncWaitHandle.