Rowan

Rowan

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DataGridView bound to BindingSource bound to KeyedCollection

Mar 13 2009 6:34 AM

Hi folks,

I am completely stuck on how to bind a KeyedCollection to a DataGridView.  I can get it to work for the first record but then it has unpredictable results when I add subsequent records.  It ends up throwing an exception at the line of code that opened the form, be that Form.ShowDialog() or Application.Run(new Form) - when the exception is thrown, it might be an InvalidOperationException or sometimes an OutOfRangeException.

I would love to find an example of how to do this, but I have not been able to find one.

Below I have included complete example of the code that causes the problem.  The following instructions will have you replicate this:

 Please do the following:

1. Create a new project using the Template "Empty Project"

2. Add a Class called Program.cs

3. open the class and delete everything in it.

4. Paste the contents of the Code Snippet below

5. Add references for:
   System.Windows.Forms
   System.Drawing

Run the program.

Click the add button

Click OK

Double click in a Cell of the DataGridView.

What am I doing wrong!?!?!?!

Begin Code

using System;
using System.Windows.Forms;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
 
namespace Project1
{
    /// <summary>
    /// The SubForm which the user sees when he adds a record.
    /// </summary>
    public partial class frmAdd : Form
    {
        public GridViewRecord gvr { get; set; }
        public frmAdd()
        {
            InitializeComponent();
            this.gvr = new GridViewRecord();
            tbFirstname.Text = gvr.FirstName;
            tbSurname.Text = gvr.Surname;
            tbOccupation.Text = gvr.Occupation;
        }
        private void btnOK_Click(object sender, EventArgs e)
        {
            gvr.FirstName = tbFirstname.Text;
            gvr.Surname = tbSurname.Text;
            gvr.Occupation = tbOccupation.Text;
            this.Close();
        }
 
    }
 
    /// <summary>
    /// the Main Form presented to the user with all the data
    /// </summary>
    public partial class frmDataGridViewDemo : Form
    {
        private RecordCollection Items;
        public frmDataGridViewDemo()
        {
            InitializeComponent();
            this.Items = new RecordCollection();
            bindingSource1.DataSource = this.Items;
            dataGridView1.DataSource = bindingSource1;
        }
        private void btnAdd_Click(object sender, EventArgs e)
        {
            frmAdd Add = new frmAdd();
            Add.ShowDialog();
            this.Items.Add(Add.gvr);
        }
    }
 
    /// <summary>
    /// The individual records that are displayed in the datagridview
    /// </summary>
    public class GridViewRecord
    {
        public string FirstName { get; set; }
        public string Surname { get; set; }
        public string Occupation { get; set; }
        public GridViewRecord()
        {
            this.FirstName = System.Guid.NewGuid().ToString();
            this.Surname = System.Guid.NewGuid().ToString();
            this.Occupation = System.Guid.NewGuid().ToString();
        }
    }
    /// <summary>
    /// The Keyed Collection with the BindingSource binds too.
    /// </summary>
    public class RecordCollection : KeyedCollection<string, GridViewRecord>
    {
        public RecordCollection() : base() { }
 
        protected override string GetKeyForItem(GridViewRecord item)
        {
            return item.FirstName;
        }
    }
 
    // ===================================================
    // BEGIN WINDOWS Designer Code
    //   Everything below this line was built by the Windows
    //   designer IDE Conglobulator.
 
 
    static class Program
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new frmDataGridViewDemo());
        }
    }
 
    partial class frmAdd
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;
 
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }
 
        #region Windows Form Designer generated code
 
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.tbFirstname = new System.Windows.Forms.TextBox();
            this.tbSurname = new System.Windows.Forms.TextBox();
            this.tbOccupation = new System.Windows.Forms.TextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.label2 = new System.Windows.Forms.Label();
            this.label3 = new System.Windows.Forms.Label();
            this.btnOK = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // tbFirstname
            // 
            this.tbFirstname.Location = new System.Drawing.Point(79, 23);
            this.tbFirstname.Name = "tbFirstname";
            this.tbFirstname.Size = new System.Drawing.Size(184, 20);
            this.tbFirstname.TabIndex = 0;
            // 
            // tbSurname
            // 
            this.tbSurname.Location = new System.Drawing.Point(79, 49);
            this.tbSurname.Name = "tbSurname";
            this.tbSurname.Size = new System.Drawing.Size(184, 20);
            this.tbSurname.TabIndex = 1;
            // 
            // tbOccupation
            // 
            this.tbOccupation.Location = new System.Drawing.Point(79, 75);
            this.tbOccupation.Name = "tbOccupation";
            this.tbOccupation.Size = new System.Drawing.Size(184, 20);
            this.tbOccupation.TabIndex = 2;
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(16, 26);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(55, 13);
            this.label1.TabIndex = 3;
            this.label1.Text = "First name";
            // 
            // label2
            // 
            this.label2.AutoSize = true;
            this.label2.Location = new System.Drawing.Point(16, 52);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(49, 13);
            this.label2.TabIndex = 4;
            this.label2.Text = "Surname";
            // 
            // label3
            // 
            this.label3.AutoSize = true;
            this.label3.Location = new System.Drawing.Point(16, 78);
            this.label3.Name = "label3";
            this.label3.Size = new System.Drawing.Size(62, 13);
            this.label3.TabIndex = 5;
            this.label3.Text = "Occupation";
            // 
            // btnOK
            // 
            this.btnOK.Location = new System.Drawing.Point(165, 101);
            this.btnOK.Name = "btnOK";
            this.btnOK.Size = new System.Drawing.Size(98, 28);
            this.btnOK.TabIndex = 6;
            this.btnOK.Text = "OK";
            this.btnOK.UseVisualStyleBackColor = true;
            this.btnOK.Click += new System.EventHandler(this.btnOK_Click);
            // 
            // frmAddForm
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(284, 141);
            this.Controls.Add(this.btnOK);
            this.Controls.Add(this.label3);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.tbOccupation);
            this.Controls.Add(this.tbSurname);
            this.Controls.Add(this.tbFirstname);
            this.Name = "frmAddForm";
            this.Text = "Add Record";
            this.ResumeLayout(false);
            this.PerformLayout();
 
        }
 
        #endregion
 
        private System.Windows.Forms.TextBox tbFirstname;
        private System.Windows.Forms.TextBox tbSurname;
        private System.Windows.Forms.TextBox tbOccupation;
        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.Label label2;
        private System.Windows.Forms.Label label3;
        private System.Windows.Forms.Button btnOK;
    }
 
    partial class frmDataGridViewDemo
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;
 
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }
 
        #region Windows Form Designer generated code
 
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.components = new System.ComponentModel.Container();
            this.dataGridView1 = new System.Windows.Forms.DataGridView();
            this.btnAdd = new System.Windows.Forms.Button();
            this.bindingSource1 = new System.Windows.Forms.BindingSource(this.components);
            ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).BeginInit();
            ((System.ComponentModel.ISupportInitialize)(this.bindingSource1)).BeginInit();
            this.SuspendLayout();
            // 
            // dataGridView1
            // 
            this.dataGridView1.AllowUserToOrderColumns = true;
            this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
            this.dataGridView1.Location = new System.Drawing.Point(15, 17);
            this.dataGridView1.Name = "dataGridView1";
            this.dataGridView1.Size = new System.Drawing.Size(488, 202);
            this.dataGridView1.TabIndex = 0;
            // 
            // btnAdd
            // 
            this.btnAdd.Location = new System.Drawing.Point(423, 224);
            this.btnAdd.Name = "btnAdd";
            this.btnAdd.Size = new System.Drawing.Size(80, 28);
            this.btnAdd.TabIndex = 1;
            this.btnAdd.Text = "Add";
            this.btnAdd.UseVisualStyleBackColor = true;
            this.btnAdd.Click += new System.EventHandler(this.btnAdd_Click);
            // 
            // frmDataGridViewDemo
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(522, 264);
            this.Controls.Add(this.btnAdd);
            this.Controls.Add(this.dataGridView1);
            this.Name = "frmDataGridViewDemo";
            this.Text = "DataGridView Demo";
            ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).EndInit();
            ((System.ComponentModel.ISupportInitialize)(this.bindingSource1)).EndInit();
            this.ResumeLayout(false);
 
        }
 
        #endregion
 
        private System.Windows.Forms.DataGridView dataGridView1;
        private System.Windows.Forms.Button btnAdd;
        private System.Windows.Forms.BindingSource bindingSource1;
    }
}