Code For dataGridView CellClick Event

amber

Hi,

m trying to fix my code for datagridview cell click event, first i've get set properties in a separate class named as PROPXI, then in another class(fee_endow) i've made a method named getfields(string field) as follows:

public static DataTable getfields(string field)
        {
            DataTable dt = new DataTable();
            using (OleDbConnection conn = new OleDbConnection(Program.constr))
            {
                if (conn.State == ConnectionState.Closed)
                    conn.Open();
                string ambi1 = "Select * FROM XI WHERE Field=@Field";
                OleDbCommand cmd = new OleDbCommand(ambi1, conn);
                cmd.Parameters.AddWithValue("@Field", field);
                OleDbDataAdapter dap = new OleDbDataAdapter(cmd);
                dap.Fill(dt);
                if (conn.State == ConnectionState.Open)
                    conn.Close();
                conn.Dispose();
            }
            return dt;
        }
Then on dataGrid Cell click event:

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            string field = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
            PROPXI pxi = fee_endow.getfields(field);
            textBox4.Text = pxi.SNO.ToString();
            textBox1.Text = pxi.NewName;
            textBox2.Text = pxi.FatherName;
            textBox3.Text = pxi.Profession;
            textBox18.Text = pxi.AcademicRecord.ToString();
            comboBox3.Text = pxi.OwnsCar;
            comboBox1.Text = pxi.ResArea;
            textBox19.Text = pxi.PerReq.ToString();
            comboBox4.Text = pxi.Dependents.ToString();
            comboBox6.Text = pxi.Widow_Divorcee;
            textBox5.Text = pxi.ResSize.ToString();
            comboBox2.Text = pxi.Unit;
            avgtotal.Text = pxi.UtilityBill.ToString();
            totalbox.Text = pxi.Edu_Expenses.ToString();
            inctotal.Text = pxi.MonthlyIncome.ToString();
            radioEarning.Checked = pxi.Earning;
            radioNoearning.Checked = pxi.NonEarning;
            radioOwned.Checked = pxi.Owned;
            radioRented.Checked = pxi.Rented;
            radioHouse.Checked = pxi.House;
            radioFlat.Checked = pxi.Flat;
            if (pxi.Earning)
            {
                radioNoearning.Checked = false;
            }
            else
            {
                radioNoearning.Checked = true;
            }
            if (pxi.Owned)
            {
                radioRented.Checked = false;
            }
            else
            {
                radioRented.Checked = true;
            }
            if (pxi.House)
            {
                radioFlat.Checked = false;
            }
            else
            {
                radioFlat.Checked = true;
            }

        }

but it's giving error:

Cannot implicitly convert type 'System.Data.DataTable' to 'Endowment.PROPXI'
plz help wts wrong with my method getfields() n code plz highlight,
Thnx

16 Replies

Know the answer? Post it — somebody with the same question will find it here.

Iftikar Hussain13y ago
Hi,
Can you please provide me the code? so that I will debug it and fix it.

Regards,
Iftikar
Vulpes13y ago
On the face of it, there are just two possible reasons for the textboxes not being updated:

1. The event-handler is not wired up to the event which can happen when code is added manually rather than via the VS designer.

2. There are no rows in the DataTable and so the code which is updating the textboxes is being by-passed.

You can check for both of these possibilities by inserting a MessageBox.Show as the first line of the method and as the first line of the 'if' block.
amber13y ago
ys i did, bt m getting nthng no syntax or logical error or exception error. nthn happens when i click on record in any cell in dataGridView, i js want dt when i click on any cell all contents should be displayed in textboxes for updation, Regards
Iftikar Hussain13y ago
what error you are getting now? Did you modify the return for getfields methods?

Regards,
Iftikar
amber13y ago
No, it didnt solve my problem:(
Iftikar Hussain13y ago
Hi,
You first need to change the return type of the method getfields from DataTable to PROPXI. and assign the value as like below
public static PROPXI getfields(int id)
{
DataTable dt = new DataTable();
using (OleDbConnection conn = new OleDbConnection(Program.constr))
{
if (conn.State == ConnectionState.Closed)
conn.Open();
string ambi1 = "Select * FROM XI WHERE Field=@Field";
OleDbCommand cmd = new OleDbCommand(ambi1, conn);
cmd.Parameters.AddWithValue("@Field", field);
OleDbDataAdapter dap = new OleDbDataAdapter(cmd);
dap.Fill(dt);
if (conn.State == ConnectionState.Open)
conn.Close();
conn.Dispose();
}
PROPXI pxi = new PROPXI();
if (dt.Rows.Count > 0)
{
DataRow dr = dt.Rows[0];
pxi.SNO = dr["SNO"].ToString();
pxi.NewName = dr["NewName"].ToString();
pxi.FatherName = dr["FatherName"].ToString();
pxi.Profession = dr["Profession"].ToString();
pxi.AcademicRecord = dr["AcademicRecord"].ToString();
}
return pxi;
}

Then it will start work.

Let me know if you need still more information

Regards,
Iftikar

Remember to click "Mark as Answer" on the post, if it helps you.
Vulpes13y ago
I thought we'd already figured this out from various posts above:

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
string field = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
DataTable dt = fee_endow.getfields(field);
if (dt.Rows.Count > 0) // check there is at least one row returned
{
DataRow dr = fee_endow.getfields(field).Rows[0];
textBox4.Text = dr["SNO"].ToString();
textBox1.Text = dr["NewName"].ToString();
textBox2.Text = dr["FatherName"].ToString();
textBox3.Text = dr["Profession"].ToString();
textBox18.Text = dr["AcademicRecord"].ToString();
comboBox3.Text = dr["OwnsCar"].ToString();
comboBox1.Text = dr["ResArea"].ToString();
textBox19.Text = dr["PerReq"].ToString();
comboBox4.Text = dr["Dependents"].ToString();
comboBox6.Text = dr["Widow_Divorcee"].ToString();
textBox5.Text = dr["ResSize"].ToString();
comboBox2.Text = dr["Unit"].ToString();
avgtotal.Text = dr["UtilityBill"].ToString();
totalbox.Text = dr["Edu_Expenses"].ToString();
inctotal.Text = dr["MonthlyIncome"].ToString();
radioEarning.Checked = Convert.ToBoolean(dr["Earning"]);
radioNoearning.Checked = Convert.ToBoolean(dr["NonEarning"]);
radioOwned.Checked = Convert.ToBoolean(dr["Owned"]);
radioRented.Checked = Convert.ToBoolean(dr["Rented"]);
radioHouse.Checked = Convert.ToBoolean(dr["House"]);
radioFlat.Checked = Convert.ToBoolean(dr["Flat"]);
if (radioEarning.Checked)
{
radioNoearning.Checked = false;
}
else
{
radioNoearning.Checked = true;
}
if (radioOwned.Checked)
{
radioRented.Checked = false;
}
else
{
radioRented.Checked = true;
}
if (radioHouse.Checked)
{
radioFlat.Checked = false;
}
else
{
radioFlat.Checked = true;
}

}
}
amber13y ago
ok like i said b4 i hav already written a code to retreive records and display in a datagridview i.e.:
in class(fee_endow):

public static DataTable getfields(string field)
        {
            DataTable dt = new DataTable();
            using (OleDbConnection conn = new OleDbConnection(Program.constr))
            {
                if (conn.State == ConnectionState.Closed)
                    conn.Open();
                string ambi1 = "Select * FROM XI WHERE Field=@Field";
                OleDbCommand cmd = new OleDbCommand(ambi1, conn);
                cmd.Parameters.AddWithValue("@Field", field);
                OleDbDataAdapter dap = new OleDbDataAdapter(cmd);
                dap.Fill(dt);
                if (conn.State == ConnectionState.Open)
                    conn.Close();
                conn.Dispose();
            }
            return dt;
        }
in another(pswd) class:

public static DataTable getfields(string field)
        {
            return fee_endow.getfields(field);
        }

on search_btn event:

private void button8_Click(object sender, EventArgs e)
        {
            dataGridView1.DataSource = pswd.getfields(comboBox5.Text);
        }

and it's working for record retreival either single or multiple, i js want a code for CELL_CLICK event, so dt after retreival when i click on any record den it should be displayed in text boxes,,
Regards,
Vulpes13y ago
It looks like the query is not returning any rows for that particular 'field' value.

To guard against that you can do:

string field = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
DataTable dt = fee_endow.getfields(field);
if (dt.Rows.Count > 0) // check there is at least one row returned
{
DataRow dr = fee_endow.getfields(field).Rows[0];
textBox4.Text = dr["SNO"].ToString();
textBox1.Text = dr["NewName"].ToString();
textBox2.Text = dr["FatherName"].ToString();
textBox3.Text = dr["Profession"].ToString();
textBox18.Text = dr["AcademicRecord"].ToString();
comboBox3.Text = dr["OwnsCar"].ToString();
// etc to the end
}

Also, you can change your getfields method slightly so that it can either deal with a single row or all rows in the database table. For the latter, pass in a field value which is null or empty:

public static DataTable getfields(string field)
{
DataTable dt = new DataTable();
bool allRows = String.IsNullOrEmpty(field);

using (OleDbConnection conn = new OleDbConnection(Program.constr))
{
if (conn.State == ConnectionState.Closed)
conn.Open();
string ambi1;
if (allRows)
{
ambi1 = "Select * FROM XI";
}
else
{
ambi1 = "Select * FROM XI WHERE Field=@Field";
}

OleDbCommand cmd = new OleDbCommand(ambi1, conn);
if(!allRows)
{
cmd.Parameters.AddWithValue("@Field", field);
}

OleDbDataAdapter dap = new OleDbDataAdapter(cmd);
dap.Fill(dt);
if (conn.State == ConnectionState.Open)
conn.Close();
conn.Dispose();
}
return dt;
}
amber13y ago
i have tried ds as u mentioned:

string field = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
            DataRow dr = fee_endow.getfields(field).Rows[0];
            textBox4.Text = dr["SNO"].ToString();
            textBox1.Text = dr["NewName"].ToString();
            textBox2.Text = dr["FatherName"].ToString();
            textBox3.Text = dr["Profession"].ToString();
            textBox18.Text = dr["AcademicRecord"].ToString();
            comboBox3.Text = dr["OwnsCar"].ToString();
            comboBox1.Text = dr["ResArea"].ToString();
            textBox19.Text = dr["PerReq"].ToString();
            comboBox4.Text = dr["Dependents"].ToString();
            comboBox6.Text = dr["Widow_Divorcee"].ToString();
            textBox5.Text = dr["ResSize"].ToString();
            comboBox2.Text = dr["Unit"].ToString();
            avgtotal.Text = dr["UtilityBill"].ToString();
            totalbox.Text = dr["Edu_Expenses"].ToString();
            inctotal.Text = dr["MonthlyIncome"].ToString();
            radioEarning.Checked = Convert.ToBoolean(dr["Earning"]);
            radioNoearning.Checked = Convert.ToBoolean(dr["NonEarning"]);
            radioOwned.Checked = Convert.ToBoolean(dr["Owned"]);
            radioRented.Checked = Convert.ToBoolean(dr["Rented"]);
            radioHouse.Checked = Convert.ToBoolean(dr["House"]);
            radioFlat.Checked = Convert.ToBoolean(dr["Flat"]);
            if (radioEarning.Checked == true)
            {
                radioNoearning.Checked = false;
            }
              else..........

now there is an exception error:
there is no row at position 0 :(
amber13y ago
hmm alright, bt my datbase contains multiple rows when select field on my form for e.g commerce or pre-medical, then shows all records in datagrid view where field is what i select, then m trying 2 write code for cell click event when i click on any record it shows dt record in textboxes,
Vulpes13y ago
I think you may have misunderstood my previous post.

If your query contains multiple rows, then it's OK for your getfields method to return a DataTable as you can then bind the DGV directly to that:

dataGridView1.DataSource = fee_endow.getfields().DefaultView;

However, if only want to get a single row, then you'd need to return a PROIPXI object (as per the code in my first post) which you can then assign to your 'pxi' variable.

An alternative way of getting a single row would be to not to bother with the PROPXI class at all but to leave the getfields method to return a DataTable and then extract the data from the first (and only) row:

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
string field = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
DataRow dr = fee_endow.getfields(field).Rows[0];
textBox4.Text = dr["SNO"].ToString();
textBox1.Text = dr["NewName"].ToString();
// etc
}
amber13y ago
No, it didnt slve my prob. still its producing that same error, i have inserted more records to the database bt dt same error:

Cannot implicitly convert type 'System.Data.DataTable' to 'Endowment.PROPXI'

on the following highlighted line:

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            string field = dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString();
            PROPXI pxi = fee_endow.getfields(field);
            textBox4.Text = pxi.SNO.ToString();
            textBox1.Text = pxi.NewName;
            textBox2.Text = pxi.FatherName;
            textBox3.Text = pxi.Profession;
            textBox18.Text = pxi.AcademicRecord.ToString();
            comboBox3.Text = pxi.OwnsCar;
            comboBox1.Text = pxi.ResArea;
            textBox19.Text = pxi.PerReq.ToString();
            comboBox4.Text = pxi.Dependents.ToString();
            comboBox6.Text = pxi.Widow_Divorcee;
            textBox5.Text = pxi.ResSize.ToString();
            comboBox2.Text = pxi.Unit;
            avgtotal.Text = pxi.UtilityBill.ToString();
            totalbox.Text = pxi.Edu_Expenses.ToString();
            inctotal.Text = pxi.MonthlyIncome.ToString();
            radioEarning.Checked = pxi.Earning;
            radioNoearning.Checked = pxi.NonEarning;
            radioOwned.Checked = pxi.Owned;
            radioRented.Checked = pxi.Rented;
            radioHouse.Checked = pxi.House;
            radioFlat.Checked = pxi.Flat;
            if (pxi.Earning)
            {
                radioNoearning.Checked = false;
            }
            else
            {
                radioNoearning.Checked = true;
            }
            if (pxi.Owned)
            {
                radioRented.Checked = false;
            }
            else
            {
                radioRented.Checked = true;
            }
            if (pxi.House)
            {
                radioFlat.Checked = false;
            }
            else
            {
                radioFlat.Checked = true;
            }

        }
can u help me fix ds and why error for the method on that line???
Vulpes13y ago
Yes, if your query produces multiple rows, then your method should work if it returns a DataTable.

You can then bind the DataTable to the DataGridView with a line such as this:

dataGridView1.DataSource = fee_endow.getfields().DefaultView
amber13y ago
thnx i appreciate it bt i have to retrieve more than one record bt ya now i ws js checking da codes so i js enetered one record there to check if it will be displayed in data grid or not :) well could it b a problem den if i enter more records in database will my code work?? plz tell Thnx in advnce
Vulpes13y ago
Well, the problem is that your getfields method is returning a DataTable but you're trying to assign it to a PROPXI variable which isn't possible.

If your query is returning (at most) one row from the database table, then I think you'd be better using a DataReader rather than a DataAdapter, populating a PROPXI object's properties with the column values for that row and then returning that. Your CellClick eventhandler should then (assuming there are no other errors) work without further ado.

I'm guessing a bit here as I don't know the types of some of the columns but something like the following. Note that if the query should return more than one row then the last one will be used:

public static PROPXI getfields(string field)
{
PROPXI pxi = new PROPXI(); // assuming constructor takes no parameters

using (OleDbConnection conn = new OleDbConnection(Program.constr))
{
if (conn.State == ConnectionState.Closed)
conn.Open();
string ambi1 = "Select * FROM XI WHERE Field=@Field";
OleDbCommand cmd = new OleDbCommand(ambi1, conn);
cmd.Parameters.AddWithValue("@Field", field);
OleDbDataReader reader = cmd.ExecuteReader();

while (reader.Read())
{
pxi.SNO = Convert.ToInt32(reader["SNO"]);
pxi.NewName = reader["NewName"].ToString();
pxi.FatherName = reader["FatherName"].ToString();
pxi.Profession = reader["Profession"].ToString();
pxi.AcademicRecord = Convert.ToInt32(reader["AcademicRecord"]);
pxi.OwnsCar = reader["OwnsCar"].ToString();
pxi.ResArea = reader["ResArea"].ToString();
pxi.PerReq = Convert.ToInt32(reader["PerReq"]);
pxi.Dependents = Convert.ToInt32(reader["Dependents"]);
pxi.Widow_Divorcee = reader["Widow_Divorcee"].ToString();
pxi.ResSize = Convert.ToInt32(reader["ResSize"]);
pxi.Unit = reader["Unit"].ToString();
pxi.UtilityBill = Convert.ToDecimal(reader["UtilityBill"]);
pxi.Edu_Expenses = Convert.ToDecimal(reader["Edu_Expenses"]);
pxi.MonthlyIncome = Convert.ToDecimal(reader["MonthlyIncomce"]);
pxi.Earning = Convert.ToBoolean(reader["Earning"]);
pxi.NonEarning = Convert.ToBoolean(reader["NonEarning"]);
pxi.Owned = Convert.ToBoolean(reader["Owned"]);
pxi.Rented = Convert.ToBoolean(reader["Rented"]);
pxi.House = Convert.ToBoolean(reader["House"]);
pxi.Flat = Convert.ToBoolean(reader["Flat"]);
}

reader.Close();

if (conn.State == ConnectionState.Open)
conn.Close();
conn.Dispose();
}

return pxi;
}