pass values

hey everyone,

okay, once again with the application. i think i should just make one thread for this thing, but the question today is: how do i send out a request to an SQL database from a form, return the data, pass that data to the original form, and then open a new form with the data passed to the orignal form?

i know its tricky so i will try and explain.


original form = form1
new form = form2
search form = form3

so form1 is told to open form3
form3 inputs data to use to search the database with
form3 completes the search
database returns matching records to form3
form3 passes these values back to form1
form1 opens a new form2 and has the data form3 passed it fill in form2


best i can do to explain what i need, i know its gonna require some public variables and probably a new class but i need to know how to make this work.

thanks

rockking

Code:

---

public partial class frmOne : Form
{
        // Constructor
        public frmOne(){}
       
        // Button click event but the code could go anywhere
        private void btnSearch_Click(object sender, EventArgs e)
        {
                DataTable searchResults;
                searchResults = frmThree.Search();
               
                frmTwo myDisplay = new frmTwo();
                myDisplay.ShowResults(searchResults);
        }
}

public partial class frmTwo : Form
{
        private DataTable m_Results;
       
        // Constructor
        public frmTwo(){}
       
        public void frmTwo_Load(object sender, EventArgs e)
        {
                // Display results in DataGridView
                dgvResults.Datasource = m_Results;
        }
       
        // Point of entry
        public void ShowResults(DataTable results)
        {
                m_Results = results;
        }
}

public partial class frmThree : Form
{
        private DataTable m_Results;
       
        // Constructor
        public frmThree
        {
                m_Results = new DataTable();
        }
       
        // Point of entry
        public DataTable Search()
        {
                this.ShowDialog();
                return m_Results;
        }
       
        // Button to search
        private void btnSearch_Click(object sender, EventArgs e)
        {
                DataSet ds = new DataSet();
                SqlConnection sqlConn = new SqlConnection("Your connection string");
                SqlDataAdapter sqlAdapter = new SqlDataAdapter("Your SQL Query", sqlConn);

                try
                {
                        sqlConn.Open();
                        sqlAdapter.Fill(ds);
                        m_Results = ds.Tables[0];

                        // User could stay on form if there is an error but close if results are there
                        this.Close();       
                }
                catch (Exception ex)
                {
                        MessageBox.Show(ex.Message);
                }
                finally
                {
                        sqlConn.Close();
                        sqlConn.Dispose();
                        sqlAdapter.Dispose();
                }
        }
}

---

Keep in mind that you cannot set UI's properties like TextBox.Text in other thread than the UI one, so if you need to do it (e.g. for displaying results computed/fetched in other thread), you have to use Control.Invoke() method.

so, now could i create a partial class that was spread across all three forms in use? or would that be a little to risky?

how do i make object references? i cant get them to work correctly, here is the code i have so far:

Code:

---

        string connectString = ConfigurationSettings.AppSettings["DbPath"];
        string icon = ConfigurationSettings.AppSettings["ciIcon"];
        object A;
        private string lastName;
        string firstName;

        public frmMBCI()
        {
            A = new object();
            A = CS_CheckInCheckOut.Search.lastName;
            ReferenceConverter a;
            a.ConvertToString(A);
            lastName = a.ConvertToString(a);
            InitializeComponent();
            this.Icon = new Icon(icon);
            textBox1.Text =  lastName.ToString();
        }

---

Do you think the ReferenceConverter? It's purpose is desing time. Just cast the reference

Code:

---

lastName = (string)a;
// OR
lastName = a as strng;

---

No, this isn't possible. Parts must form together single class.

okay so i have it working between form1 and form3

so how do i get it so that form2 tells form1 the value for form3 to read?

form1

Code:

---

public partial class frmMain : Form
    {
        public static string lastName;
        string firstName;
        string connectString = ConfigurationSettings.AppSettings["DbPath"];
        string mainIcon = ConfigurationSettings.AppSettings["mainIcon"];
        public frmMain()
        {
            InitializeComponent();
            this.KeyDown += new KeyEventHandler(frmMain_KeyDown);
            this.PreviewKeyDown += new PreviewKeyDownEventHandler(frmMain_PreviewKeyDown);
            textBox1.Text = "Last Name";
            textBox2.Text = "First Name";
            this.Icon = new Icon(mainIcon);
        }

        void frmMain_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.End:
                    {
                        e.IsInputKey = true;
                        break;
                    }
            }
        }

        void frmMain_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.End:
                    {
                        this.Close();
                        break;
                    }
            }
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            lastName = textBox1.Text;
        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {
            firstName = textBox2.Text;
        }

        private void button1_Click(object sender, EventArgs e)
        {
          /* SqlConnection dataConnection = new SqlConnection();
            dataConnection.ConnectionString = "Data Source=DELL\\SQLEXPRESS;Initial Catalog=Learning_DB;User ID=jsitz;Password=labR2o6";
            SqlCommand dataCommand = new SqlCommand();
            try
            {
                dataConnection.Open();
                dataCommand.CommandText = "INSERT INTO Learning_Table([last name]) VALUES ('" + lastName + "')";
                dataCommand.ExecuteNonQuery();

            }
            finally
            {
                dataConnection.Close();
            }*/
          /* using (var conn = new SqlConnection("Data Source=DELL\\SQLEXPRESS;Initial Catalog=Learning_DB;User ID=jsitz;Password=labR2o6"))
            {
                using (var cmd = new SqlCommand("INSERT INTO Learning_Table([Last Name], [First Name]) VALUES('"+ lastName +"', '"+ firstName +"')", conn))
                {
                    conn.Open();
                    cmd.ExecuteNonQuery();
                }
            }
            */

            using (var conn = new SqlConnection(connectString))
            {
                using (var cmd = new SqlCommand("[dbo].[Learning.Delete]", conn))
                {
                    conn.Open();

                    //set command type to stored procedure
                    cmd.CommandType = CommandType.StoredProcedure;

                    //Add input parameters
                    cmd.Parameters.AddWithValue("@LastName", lastName);
                    cmd.Parameters.AddWithValue("@FirstName", firstName);

                    //add output parameters
                    cmd.Parameters.Add("@NewLearningId", SqlDbType.Int);
                    cmd.Parameters[2].Direction = ParameterDirection.Output;

                    //execute
                    cmd.ExecuteNonQuery();

                    //retrieve inserted id
                    //newLearningId = (int) cmd.Parameters[2];
                }
            }


            MessageBox.Show("Successfully added " + lastName + ", " + firstName, "Success", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            textBox1.Text = "Last Name";
            textBox2.Text = "First Name";
        }

        private void checkInToolStripMenuItem2_Click(object sender, EventArgs e)
        {
            /*frmMBCI mbci = new frmMBCI();
            mbci.ShowDialog();
            */
            Search search = new Search();
            search.ShowDialog();
            lastName = CS_CheckInCheckOut.Search.lastName;
        }

        private void quitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.Close();
        }
    }

---

form2

Code:

---

    public partial class Search : Form
    {
        string icon = ConfigurationSettings.AppSettings["searchIcon"];
        public static string lastName;
        string firstName;
        public Search()
        {
            InitializeComponent();
            this.Icon = new Icon(icon);
        }

        private void txtLName_TextChanged(object sender, EventArgs e)
        {
            lastName = txtLName.Text;
            CS_CheckInCheckOut.frmMain.lastName = lastName;
        }

        private void btnQuery_Click(object sender, EventArgs e)
        {
            frmMBCI mbci = new frmMBCI();
            mbci.ShowDialog();
            this.Close();
        }

    }

---

form3

Code:

---

public partial class frmMBCI : Form
    {
        string connectString = ConfigurationSettings.AppSettings["DbPath"];
        string icon = ConfigurationSettings.AppSettings["ciIcon"];
        object A;
        string lastName;
        string firstName;

        public frmMBCI()
        {
            InitializeComponent();
            A = new object();
            A = CS_CheckInCheckOut.frmMain.lastName;
            //ReferenceConverter a;
            //a.ConvertToString(A);
            lastName = (string)A;
           
            this.Icon = new Icon(icon);
            textBox1.Text = lastName;//(string)A;
        }
}

---

are there any special variable types that i should be using? or am i just going the wrong way about all this?

so here is what i am trying. i now have the 3 forms and another class named variables

variables has all the variables needed to be used between all the forms
so how do i make the values of the variables in class variables change to whatever is assigned to them from and of the forms? here is how it would go

form3 tells variable studentLastName a value
form3 closes
form2 opens and reads the variable studentLastName
studentLastName now becomes the text of a text box

much simpler and less confusing this time

but what type of variable should i make each variable? currently they are all "public static string"
is this the proper type to use?