Two bindings in the collection to bind to the same property: Exception

[sudhanshu]

Hi there,

I have created a windows form through which user can update delete or add records in the table. I have made in such a way that if user chooses update or delete option in the form all the textboxes and comboboxes get populated with the data automatically from the database I am using databinding properties. It works fine but if I choose delete after choosing update application crashes with the exception: This causes two bindings in the collection to binf\d to the same property.

I am even clearing the databindings before using them.

Here is the code...Since I m a newbie in C# please answer in simple terms..

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;

namespace RMC
{
    public partial class frmdatabaserole : Form
    {
       public string rolename,exp,qualification,skillset;
       public bool Add = false,update=false,Delete=false;
       private OleDbConnection connection;
       private OleDbCommand cmd = new OleDbCommand();
       cmd.Connection = connection;
       cmd.CommandType = CommandType.Text;
       cmd.CommandText = "select * from Role_Desc;";
       private OleDbDataAdapter da1= new OleDbDataAdapter(cmd);    
       private DataSet ds=new DataSet();
       private DataViewManager dsView;
       MDIParent1 parentrl;
        public frmdatabaserole(MDIParent1 parent)
        {
            parentrl = parent;
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {    
            if (Add == true)
            {
                parentrl.updateroledb('a',textBox1.Text, textBox2.Text, maskedTextBox1.Text, textBox4.Text);  
            }

            else if (update == true)
            {
                MessageBox.Show(comboBox1.Text + textBox4.Text + maskedTextBox1.Text);
                parentrl.updateroledb('c', comboBox1.Text, textBox2.Text, maskedTextBox1.Text, textBox4.Text);
            }
            else if (Delete == true)
            {
                if(MessageBox.Show(this, "Are you sure you want to delete" + comboBox1.Text + "record", "Warning",MessageBoxButtons.YesNo)==DialogResult.Yes)

                    parentrl.updateroledb('d',comboBox1.Text, textBox2.Text, maskedTextBox1.Text, textBox4.Text);
                else
                    return;            
            }       
            this.Close();
        }
        private void radioButton1_CheckedChanged(object sender, EventArgs e)

        {

            button1.Text = "Add";
            comboBox1.Hide();
            textBox1.Show();
            groupBox2.Enabled = true;
            Add = true;
        }
        private void binddata()
        {
            try
            {
                connection = new OleDbConnection("Provider=Microsoft.JET.OleDb.4.0;Data Source=C:\\Documents and Settings\\pavan\\Desktop\\sudhanshu\\MSaccess\\Database1.mdb;");
                connection.Open();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return;
            }
            MessageBox.Show("Connected");
            da1.TableMappings.Clear();
            da1.TableMappings.Add("Table", "Role_Desc");
            da1.Fill(ds, "Role_Desc");
            //da1.TableMappings.Add("Table","Role_Desc");
            dsView = ds.DefaultViewManager;
            comboBox1.DataBindings.Clear();
            comboBox1.DataSource = dsView;
            comboBox1.DisplayMember = "Role_Desc.Rol_name";
            comboBox1.ValueMember = "Role_Desc.Rol_ID";
            comboBox1.Show();
            textBox2.DataBindings.Clear();
            textBox2.DataBindings.Add("Text", dsView, "Role_Desc.Rol_SkillSet");
            textBox2.DataBindings.Clear();
            textBox4.DataBindings.Add("Text", dsView, "Role_Desc.Rol_qlfctn");
            maskedTextBox1.DataBindings.Clear();
            maskedTextBox1.DataBindings.Add("Text", dsView, "Role_Desc.Rol_Exp");
            connection.Close();
        }
        private void radioButton2_CheckedChanged(object sender, EventArgs e)
        {
            textBox1.Hide();
            button1.Text = "Update";
            binddata();
            update = true;
            groupBox2.Enabled = true;
        }
        private void radioButton3_CheckedChanged(object sender, EventArgs e)
        {
            textBox1.Hide();
            comboBox1.Show();
            binddata();
            button1.Text = "Delete";
            Delete = true;
            groupBox2.Enabled = true;
         }
        private void button2_Click(object sender, EventArgs e)
        {
            this.Close();
        }
        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

    }


}

[Hack]

Welcome to the forums

It works fine but if I choose delete after choosing update application crashes with the exception: This causes two bindings in the collection to binf\d to the same property.

What is the exception?

[techgnome]

Not sure what the exception is ... or where... but I did spot an error in the code:

            textBox2.DataBindings.Clear();
            textBox2.DataBindings.Add("Text", dsView, "Role_Desc.Rol_SkillSet");
            textBox2.DataBindings.Clear(); // Did you REALLY mean to do this? Look at the name CAREFULLY!
            textBox4.DataBindings.Add("Text", dsView, "Role_Desc.Rol_qlfctn");

This is why it's generally a good idea to give your controls a meaningful name as soon as possible.

-tg

EDIT - ah... yes.... that line I noted is the source of the problem. It's not clearing out the bindings on Textbox4, so when you try to add a new binding on the next line, the exception is thrown.