ComboBox Items Disappearing while Re binding

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In my application i have a combo-box with list of some data from DB. The combo-box data-source is given set to a binding source. The binding source has a data-set as Data-source and a Data-table as data-member.
I update this combo-box after adding or editing or deleting an entry. The updating is done by again calling the code for binding. Now all the items in the combo-box disappears.
I don't know how it happens.

A sample work is in the link http://www.filedropper.com/students_1. the db is included with it.

Posted 6-Sep-12 21:52pm

good.shankar

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Kuthuparakkal 7-Sep-12 3:56am

post the code buddy

good.shankar 7-Sep-12 4:05am

code in the link...

Kuthuparakkal 7-Sep-12 4:26am

not everybody got time to sign-in to that crap, download your solution, unzip and read it. Would you do this, seriously i do not.

CodeHawkz 7-Sep-12 4:30am

WOahhh Kuthuparakkal. Shouldn't you be a bit concerned about your language in such a public forum? I suggest you reflect more professionalism in future. Btw, you don't have to sign into that site, just click the link and fill in the captcha code and the file is downloaded.

Regards

Kuthuparakkal 7-Sep-12 4:39am

No worries, please do the way you like, no offence. But expectation reduces joy. Thats just happened here!

good.shankar 7-Sep-12 4:46am

sorry My Code

public partial class Students : Form
{
DBOprX dbOpr = new DBOprX();
BindingSource bs = new BindingSource(new System.ComponentModel.Container());
DataSet ds = new DataSet();

public Students()
{
InitializeComponent();
}

private void btnAdd_Click(object sender, EventArgs e)
{
if (Validate())
{
return;
}
dbOpr.ExecuteMSSQLQry("INSERT INTO Stu (Name, Address, Phone) VALUES ('" + txtName.Text + "', '" + txtAddress.Text + "', '" + txtPhone.Text + "')");

Reset();
GetData();
}

private void btnUpdate_Click(object sender, EventArgs e)
{
if (Validate())
{
return;
}
dbOpr.ExecuteMSSQLQry("UPDATE Stu SET Name = '" + txtName.Text + "', Address = '" + txtAddress.Text + "', Phone = '" + txtPhone.Text + "' WHERE Id = " + cboStudents.SelectedValue.ToString() + "");

Reset();
GetData();
}

private void btnDelete_Click(object sender, EventArgs e)
{
dbOpr.ExecuteMSSQLQry("DELETE FROM Stu WHERE Id = " + cboStudents.SelectedValue.ToString() + "");

Reset();
GetData();
}

private void btnReset_Click(object sender, EventArgs e)
{
Add();
Reset();
//RefreshData();
}

private void Students_Load(object sender, EventArgs e)
{
GetData();
Add();
}

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
Int32 q;
if (cboStudents.SelectedIndex == -1 || !Int32.TryParse(cboStudents.SelectedValue.ToString(),out q))
{
return;
}

ds = dbOpr.SelectMSSQLQry("SELECT * FROM Stu WHERE Id = '" + cboStudents.SelectedValue.ToString() + "'", "StuDetails");

if (ds.Tables["StuDetails"].Rows.Count == 0)
{
return;
}

txtName.Text = ds.Tables["StuDetails"].Rows[0]["Name"].ToString();
txtAddress.Text = ds.Tables["StuDetails"].Rows[0]["Address"].ToString();
txtPhone.Text = ds.Tables["StuDetails"].Rows[0]["Phone"].ToString();

Edit();
}

void Reset()
{
txtName.ResetText();
txtAddress.ResetText();
txtPhone.ResetText();
cboStudents.SelectedIndex = -1;
}

void Add()
{
btnAdd.Enabled = true;
btnUpdate.Enabled = false;
btnDelete.Enabled = false;
}

void Edit()
{
btnAdd.Enabled = false;
btnUpdate.Enabled = true;
btnDelete.Enabled = true;
}

void GetData()
{
ds = dbOpr.SelectMSSQLQry("Select * FROM Stu", "Students");

bs.DataMember = "Students";
bs.DataSource = ds;

cboStudents.DataSource = bs;
cboStudents.DisplayMember = "Name";
cboStudents.ValueMember = "Id";

cboStudents.SelectedIndex = -1;
}

bool Validate()
{
if (String.IsNullOrEmpty(txtName.Text))
{
MessageBox.Show("Please Enter Name");
return true;
}
return false;
}

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Kuthuparakkal · Accepted Answer · 2012-09-07T00:08:00

Change the definitions:

C#

DBOprX dbOpr = new DBOprX();
BindingSource bs = new BindingSource(new System.ComponentModel.Container());
DataSet ds = new DataSet();

to:

C#

DBOprX dbOpr;
BindingSource bs;
DataSet ds;

Change the GetData()

C#

void GetData()
{
dbOpr = new DBOprX();
bs = new BindingSource(new System.ComponentModel.Container());
ds = new DataSet();
ds = dbOpr.SelectMSSQLQry("Select * FROM Stu", "Students");
bs.DataMember = "Students";
bs.DataSource = ds;

cboStudents.DataSource = bs;
cboStudents.DisplayMember = "Name";
cboStudents.ValueMember = "Id";

cboStudents.SelectedIndex = -1;
}