C# delegates problem
- by Mick Taylor
Hello I am getting the following error from my C# Windows Application:
Error 1 No overload for 'CreateLabelInPanel' matches delegate 'WorksOrderStore.ProcessDbConnDetailsDelegate' H:\c\WorksOrderFactory\WorksOrderFactory\WorksOrderClient.cs 43 39 WorksOrderFactory
I have 3 .cs files that essentially:
Opens a windows
Has an option for the users to connect to a db
When that is selected, the system will go off and connect to the db, and load some data in (just test data for now)
Then using a delegate, the system should do soemthing, which for testing will be to create a label. However I haven't coded this part yet.
But I can't build until I get this error sorted.
The 3 fiels are called:
WorksOrderClient.cs (which is the MAIN)
WorksOrderStore.cs
LoginBox.cs
Here's the code for each file:
WorksOrderClient.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using WorksOrderStore;
namespace WorksOrderFactory
{
using WorksOrderStore;
public partial class WorksOrderClient : Form
{
LoginBox lb = new LoginBox();
private static WorksOrderDB wodb = new WorksOrderDB();
private static int num_conns = 0;
public WorksOrderClient()
{
InitializeComponent();
}
private void connectToADBToolStripMenuItem_Click(object sender, EventArgs e)
{
lb.ShowDialog();
lb.Visible = true;
}
public static bool createDBConnDetObj(string username, string password, string database)
{
// increase the number of connections
num_conns = num_conns + 1;
// create the connection object
wodb.AddDbConnDetails(username, password, database, num_conns);
// create a new delegate object associated with the static
// method WorksOrderClient.createLabelInPanel
wodb.ProcessDbConnDetails(new ProcessDbConnDetailsDelegate(CreateLabelInPanel));
return true;
}
static void CreateLabelInPanel(DbConnDetails dbcd)
{
Console.Write("hellO");
string tmp = (string)dbcd.username;
//Console.Write(tmp);
}
private void WorksOrderClient_Load(object sender, EventArgs e)
{
}
}
}
WorksOrderStore.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using WorksOrderFactory;
namespace WorksOrderStore
{
using System.Collections;
// Describes a book in the book list:
public struct WorksOrder
{
public string contractor_code { get; set; } // contractor ID
public string email_address { get; set; } // contractors email address
public string date_issued { get; set; } // date the works order was issued
public string wo_ref { get; set; } // works order ref
public string status { get; set; } // status ... not used
public job_status js { get; set; } // status of this worksorder within this system
public WorksOrder(string contractor_code, string email_address, string date_issued, string wo_ref) : this()
{
this.contractor_code = contractor_code;
this.email_address = email_address;
this.date_issued = date_issued;
this.wo_ref = wo_ref;
this.js = job_status.Pending;
}
}
// Declare a delegate type for processing a WorksOrder:
//public delegate void ProcessWorksOrderDelegate(WorksOrder worksorder);
// Maintains a worksorder database.
public class WorksOrderDB
{
// List of all worksorders in the database:
ArrayList list = new ArrayList();
// Add a worksorder to the database:
public void AddWorksOrder(string contractor_code, string email_address, string date_issued, string wo_ref)
{
list.Add(new WorksOrder(contractor_code, email_address, date_issued, wo_ref));
}
// Call a passed-in delegate on each pending works order to process it:
/*public void ProcessPendingWorksOrders(ProcessWorksOrderDelegate processWorksOrder)
{
foreach (WorksOrder wo in list)
{
if (wo.js.Equals(job_status.Pending))
// Calling the delegate:
processWorksOrder(wo);
}
}*/
// Add a DbConnDetails to the database:
public void AddDbConnDetails(string username, string password, string database, int conn_num)
{
list.Add(new DbConnDetails(username, password, database, conn_num));
}
// Call a passed-in delegate on each dbconndet to process it:
public void ProcessDbConnDetails(ProcessDbConnDetailsDelegate processDBConnDetails)
{
foreach (DbConnDetails wo in list)
{
processDBConnDetails(wo);
}
}
}
// statuses for worksorders in this system
public enum job_status
{
Pending,
InProgress,
Completed
}
public struct DbConnDetails
{
public string username { get; set; } // username
public string password { get; set; } // password
public string database { get; set; } // database
public int conn_num { get; set; } // this objects connection number.
public ArrayList woList { get; set; } // list of works orders for this connection
// this constructor just sets the db connection details
// the woList array will get created later .. not a lot later but a bit.
public DbConnDetails(string username, string password, string database, int conn_num) : this()
{
this.username = username;
this.password = password;
this.database = database;
this.conn_num = conn_num;
woList = new ArrayList();
}
}
// Declare a delegate type for processing a DbConnDetails:
public delegate void ProcessDbConnDetailsDelegate(DbConnDetails dbConnDetails);
}
and LoginBox.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WorksOrderFactory
{
public partial class LoginBox : Form
{
public LoginBox()
{
InitializeComponent();
}
private void LoginBox_Load(object sender, EventArgs e)
{
this.Visible = true;
this.Show();
//usernameText.Text = "Username";
//new Font(usernameText.Font, FontStyle.Italic);
}
private void cancelBtn_Click(object sender, EventArgs e)
{
this.Close();
}
private void loginBtn_Click(object sender, EventArgs e)
{
// set up a connection details object.
bool success = WorksOrderClient.createDBConnDetObj(usernameText.Text, passwordText.Text, databaseText.Text);
}
private void LoginBox_Load_1(object sender, EventArgs e)
{
}
}
}
Any ideas??
Cheers,
m
